Text message reminders for improving sun protection habits: A systematic review.

BACKGROUND: Excessive exposure to ultraviolet radiation increases the risk of skin cancer and other conditions. SMS text reminders may be a useful tool to improve sun protection habits due to its massive reach, low cost, and accessibility.
OBJECTIVE: To perform a systematic review of randomized controlled trials (RCTs) that evaluated the effects of SMS text reminders in promoting sun protection habits.
METHODS: We performed a systematic search in PubMed, Central Cochrane Library, and Scopus; following the PRISMA recommendations to perform systematic reviews. We included RCTs published up to December 2018, which evaluated the benefits and harms of SMS text reminders to improve sun protection habits. Random-effects meta-analyses were performed whenever possible. The certainty of the evidence was assessed for RCTs estimates using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. The study protocol was registered in PROSPERO (CRD42018091661).
RESULTS: Five RCTs were included in this review. When pooled, the studies found no effect of SMS text reminders in "sunburn anytime during follow-up" (two studies, risk ratio: 0.93; 95% confidence interval: 0.83-1.05). Contradictory results were obtained for sunscreen use (three RCTs) and sun protection habits (two RCTs), however, they could not be meta-analyzed because outcomes were measured differently across studies. The certainty of the evidence was very low for these three outcomes according to GRADE methodology.
CONCLUSIONS: RCTs that assessed effects of SMS text reminders did not find a significant benefit on objective outcomes, such as having a sunburn, sunscreen use and composite score of sun protection habits. Since certainty of the evidence was very low, future high-quality studies are needed to reach a conclusion regarding the balance of desirable and undesirable outcomes. PROTOCOL REGISTRATION NUMBER: PROSPERO (CRD42018091661).

Introduction

Excessive exposure to ultraviolet (UV) radiation increases the risk for developing severe diseases, such as skin cancer (especially melanoma and basal cell carcinoma) [1], macular degeneration, and cataracts [2]. Sun protection habits to diminish this exposure include sunscreen use, wearing a hat, wearing sunglasses, wearing clothes that protects vulnerable skin areas, avoidance of exposure during peak UV hours around solar noon, and seeking shade or staying indoors [3]. Accordingly, educational interventions to enhance compliance with sun protection habits have been proposed, and considerable effects have been observed in certain groups, such as melanoma survivors, parents of young children, and medical professionals [4-6].

Evidence about the effects of mass media interventions in health outcomes, such as oral and print-based health promotion campaigns, suggests their usefulness, but is limited by the study designs and problems in the measurement of the outcome, moreover, these interventions are not usually tailored [7]. In this way, there is growing interest in technology-based interventions, such as the use of mobile applications [8], electronic mails [9] and short message service text message reminders (SMS text reminders) [10, 11]. Some systematic reviews have synthesized the evidence of the effects of SMS text reminders and mobile applications in medication adherence and management, in adolescents [12-14] and adults [15], supporting their feasibility and acceptability. Nevertheless, all of those reviews recommended future studies with a more fitting design.

Using SMS text reminders can be an appropriate strategy to improve sun protection habits due to its massive reach, low cost, accessibility in space and time, the potential for tailoring, and the possibility to interact with the sender [8, 16, 17]. Additionally, an increasing number of people are using mobile devices to obtain health information [8]. Consequently, SMS text reminders have been used in the management of several diseases, such as diabetes and asthma, and on the improvement of different habits, such as weight loss, smoking cessation, exercising or physical activity [8, 18] and sun protection [6].

The effects of SMS text reminders in sun protection habits have been evaluated through randomized controlled trials (RCTs). However, their results have not been synthesized, which hinders the decision-making process on this subject. Thus, the objective of this study was to perform a systematic review of RCTs to evaluate the effects of SMS text reminders in promoting sun protection habits.

Methods

Protocol and registration

We performed a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) recommendations [19]. The study protocol has been registered at PROSPERO (CRD42018091661).

Information sources, search and study selection

For this systematic review, we included all RCTs that directly evaluated the effects of SMS text reminders on outcomes related to sun protection habits in the SMS receivers.

Searching was performed in two steps: 1) a systematic search in three databases, and 2) a review of all documents that have cited any of the studies included in step 1, and of all the references of the studies included in step 1.

To carry out step 1, we performed a literature search in three databases: PubMed, Central Cochrane Library (CENTRAL), and Scopus. No restrictions in language or publication date were applied. The last research update was performed in December 2018. The detailed search strategy for this step is available on S1 Material. We downloaded all found references to an EndNote document, and eliminated duplicated articles using this software. After that, we assessed titles and abstracts to identify potential studies for inclusion. Lastly, we assessed the full-text of these potential studies to determine their eligibility. The complete list of articles that were excluded in the full-text assessment is detailed in S2 Material.

For step 2, during February 2019, we reviewed all documents that have cited any of the studies included in the first step, using Google Scholar (https://scholar.google.com.pe/), and we reviewed all the references of the studies included in step 1. Later, we collected all articles that met the inclusion criteria.

Both steps were performed independently by two reviewers (DCM and WAT). When disagreements occurred, they were discussed by all authors and resolved by consensus.

Data extraction

Two independent authors (DCM and WAT) extracted the following information of the included studies into a Microsoft Excel worksheet: author, year of publication, title, population (inclusion and exclusion criteria), setting, intervention (duration, frequency, and activities), comparator (duration, frequency, and activities), time of follow-up, and effects of SMS text reminders. When disagreements were found, the full-text articles were reviewed again by the authors.

Risk of bias and certainty of the evidence

To evaluate the risk of bias of included RCTs, we used the Revised Cochrane risk of bias tool for randomized trials version 2.0 (RoB 2) [20], published in October 2018. This tool assesses the risk of bias in five domains per outcome of interest: bias arising from the randomization process, bias due to deviations from the intended interventions (effect of assignment to intervention), bias due to missing outcome data, bias in measurement of the outcome, and bias in selection of the reported results; and one overall judgment. For each of the domains, the overall risk of bias (low risk, some concerns, and high risk) was established according to the judgment of their signaling questions.

To assess the certainty of the evidence for each outcome, we used The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology [21], which evaluates the risk of bias, inconsistency, indirectness, imprecision and publication bias.

Statistical analysis

For each outcome of each study, we calculated and reported the intervention effects as mean differences (MDs) or risk ratios (RRs) along with their 95% confidence intervals (95% CIs).

When two or more studies presented the same outcome in a similar fashion, we performed a meta-analysis using random-effects models (Mantel-Haenszel method) due to heterogeneity across studies interventions [22]. Meta-analyses were performed using Review Manager Software Version 5.3.

We assessed heterogeneity using the I2 statistics, and we considered that heterogeneity might not be important when I2 < 40% [23]. Publication bias was not assessed since the number of studies pooled for each meta-analysis was less than ten [23].

Results

Studies selection

We found 1,333 records in databases searching. After duplicates removal, we screened 1,092 records, from which we reviewed 34 full-text documents, and finally included six papers [24-29]. Later, we searched documents that cited any of the initially included studies as well as the references of the initially included studies. However, no extra articles that fulfilled inclusion criteria were found in these searches (Fig 1).

Fig 1

Flowchart of study selection.

The six included papers reported results of five RCTs since two papers reported results from the same RCT: Youl 2015 [26] and Janda 2013 [27]. We will cite only Youl’s paper to refer to this study since it was the one that presented results of interest.

Characteristics

Of these five RCTs, three studies [24, 25, 29] were performed in the United States and two studies [27, 28] in Australia. Two studies [24, 28] were performed during summer months according to its hemisphere. Regarding the population characteristics, three studies [27-29] were performed in community dwellers; the female proportion ranged from 8.4% to 100%, and the mean age ranged from 31.6 to 44.2 years.

Regarding the intervention, it consisted of delivering SMS text reminders on sun protection habits, such as sunscreen use and skin self-examination, with heterogeneous frequency (range: three to seven days) and duration (range: one to twelve months). Of the five RCTs, two of them tailored the messages according to the baseline characteristics of participants, using the health belief model constructs [24, 25].

The control group received a 30-minutes educative PowerPoint presentation in one study [24], while in the other four studies [25, 26, 28, 29] this group received SMS text reminders about other topics, such as physical activity or sex protection (Table 1 and S3 Material).

Table 1

Study and participants’ characteristics in the included RCTs.

First author, year (country)	Design	Study settings	Follow-up period	Intervention details	Funding
Duffy, 2018 (USA) [24]	Parallel RCT	Outdoor workers	5 months	Messages guided by the health belief model constructs	The Blue Cross Blue Shield of Michigan Foundation
Darlow, 2017 (USA) [25]	Parallel RCT	Young adult women from a metropolitan region of the USA northeast	4 weeks	Messages guided by the health belief model constructs	The Aetna Foundation
Youl, 2015 & Janda, 2013 (Australia) [26, 27]	Parallel RCT	Community dwellers (participants from the Queensland electoral and Medicare rolls)	3 & 12 months	Personalized messages based on the social cognitive theory, which used a conversational tone	Australian National Health and Medical Research Council (NHMRC)
Gold, 2011 (Australia) [28]	Parallel RCT	Community dwellers	4 months	Humorous, short, used informal language and were linked to particular annual events where possible	VicHealth Discovery Grant The Australian Government Monash University Faculty of Medicine NHMRC
Armstrong, 2009 (USA) [29]	Parallel RCT	Community dwellers	6 weeks	Two components: a text detailing daily local weather information and a text reminding users to apply sunscreen	Information Systems Council of Massachusetts General Hospital and Brigham and Women’s Hospital

* SMS + mailed sunscreen + education, versus mailed sunscreen + education. SMS + education, versus education only

SSE: skin self-examination

Risk of bias

The risk of bias was assessed using the RoB 2. Regarding the randomization process, three studies had some concerns, while three studies had a high risk of bias in the measurement of the outcome. Only one study had a low risk of bias in most domains [29]. Four studies had a high risk of bias in the overall judgment (Fig 2).

Fig 2

Risk of bias of the included studies.

Outcome effects

Several objective outcomes were reported by the included studies. Some of them were the number of sunburns, sunscreen use, sun protection habits (protecting clothes, wearing sunglasses, wearing a hat, etc.), skin self-examination, attempted suntan and adherence rate of sunscreen application.

In Darlow’s study [25], only two results are briefly presented in the paper text, but the number of participants in each group could not be extracted, so we could not calculate MDs’ confidence intervals (Table 2).

Table 2

Characteristics of the included studies.

First author, year (country)	Number of participants at baseline (intervention/control)	Frequency and duration of SMS	Gender (female %)	Mean age in years	Follow-up	Outcomes effects
Duffy, 2018 (USA) [24]	First comparison: 93/87, second comparison: 86/911	Three random weekdays during 5 months	8.4%	44.2	5 months	At least one sunburn: First comparison1: RR: 1.09 (0.84–1.41) Second comparison1: RR: 0.85 (0.68–1.08) Sunscreen use (5-point Likert scale: from never to always): First comparison1: MD: 0.1 (-0.3 to 0.5) Second comparison1: MD: 0.2 (-0.2 to 0.6) Number of sunburns: First comparison1: MD: 0.0 (-0.4 to 0.4) Second comparison1: MD: -0.2 (-0.6 to 0.2)
Darlow, 2017 (USA) [25]	104 participants distributed in 4 groups	Every day during 2 weeks	100%	Not reported	4 weeks	The paper does not bring enough information to assess the effects of SMS in any outcome
Youl, 2015 & Janda, 2013 (Australia) [26, 27]	187/183	Weekly for the first 3 months and monthly during the following 9 months	67%	31.6 (sun protection), 31.8 (control)	3 months	Sun protection habits index (4-points Likert scale): MD: 0.02 (-0.07 to 0.11) Any skin self-examination (SSE) in the past 3 months: RR: 1.13 (0.84 to 1.51) Whole-body SSE at time of the last SSE: RR: 1.02 (0.66 to 1.57)
					12 months	Sun protection habits index (4-points likert scale): MD: 0.13 (0.03 to 0.23) Any skin self-examination (SSE) in past 3 months: RR: 1.22 (0.95–1.56) Whole-body SSE at time of last SSE: RR: 1.27 (0.72 to 2.25) Any sunburn in the past 12 months: RR: 0.96 (0.84 to 1.10) Two or more sunburns in past 12 months: RR: 0.88 (0.67 to 1.16) Attempted suntan in past 12 months: RR: 0.95 (0.58 to 1.57)
Gold, 2011 (Australia) [28]	200/158	Fortnightly during 4 months	39.9%	Not reported	4 months	Preference for a dark tan: RR: 1.13 (0.59 to 2.16) Consideration of the long-term consequences of prolonged UV exposure: RR: 1.01 (0.84 to 1.20) Usually/always wears hat: RR: 1.11 (0.80 to 1.52) Usually/always wears sunscreen: RR: 0.95 (0.73 to 1.23) Usually/always seeks shade: RR: 1.00 (0.77 to 1.31) Usually/always wears deliberately skimpy clothing: RR: 0.96 (0.66 to 1.41)
Armstrong, 2009 (USA) [29]	35/35	Every day during 6 weeks	70%	32.9 (SMS) / 34.3 (control)	6 weeks	Adherence rate of sunscreen application: MD: 11 (6.5 to 15.5)

1 (intervention: SMS + mailed sunscreen + education) vs (control: mailed sunscreen + education). (intervention: SMS + education) vs (control: education only).

The risk ratios (RRs) and mean differences (MDs) were unadjusted.

Statistically significant results were in bold.

First comparison: RR: 1.09 (0.84–1.41)

Second comparison: RR: 0.85 (0.68–1.08)

First comparison: MD: 0.1 (-0.3 to 0.5)

Second comparison: MD: 0.2 (-0.2 to 0.6)

First comparison: MD: 0.0 (-0.4 to 0.4)

Second comparison: MD: -0.2 (-0.6 to 0.2)

Although many outcomes were assessed, only sunburn anytime during follow-up was measured similarly in two studies [24, 26], so we could perform a meta-analysis. Although Duffy´s study had two comparisons, we used only the one that did not include mailed sunscreen for meta-analysis, because we considered that this comparison was the most similar to the result of the other study. The meta-analysis showed a pooled RR of 0.93 (95% CI: 0.83 to 1.05) (Fig 3). This result had a very low certainty of evidence (Table 3).

Fig 3

Forest plot for the effect of SMS messages in having a sunburn anytime during follow-up.

Table 3

Summary of findings.

Outcomes	Absolute anticipated effects (95% CI)		Relative effect (95% CI)	No. of participants (Trials)	Certainty of the evidence (GRADE)
	Control group	Intervention group
Sunburn anytime during follow-up (follow-up: from 5 to 12 months)	722 per 1,000	672 per 1,000 (600 to 759)	RR 0.93 (0.83 to 1.05)	487 (2 RCTs: Duffy, Youl) (24, 26)	⨁◯◯◯ VERY LOW a,b
Sunscreen use (follow-up: 6 weeks to 5 months)	Of the three RCTs that assessed this outcome, only one (Armstrong, the one with the lowest population) found a significant difference between intervention and control group.			785 (3 RCTs: Duffy, Gold, & Armstrong) (24, 28, 29)	⊕◯◯◯ VERY LOW c,d
Sun protection habits (follow-up: 3 months to 12 months)	Two studies: The first study used a composite score of sun protection habits index (score range: 1–4), found no difference at 3 months of follow-up, but found a slight difference at 12 months (2.63 vs 2.50 on average) The second study did not find differences in wearing a hat, seeking shade, or using skimpy clothing			728 (2 RCTs: Youl & Gold) (26, 28)	⨁◯◯◯ VERY LOW a,d

CI: Confidence Interval; MD: Mean difference; RR: Risk ratio; RCT: randomized controlled trial

For the sunscreen use outcome, a narrative summary of the evidence was performed, since each study assessed the outcome differently

Explanations:

a. We rated down two levels for risk of bias since the two RCTs had high risk of bias in the overall judgment

b. We rated down one level for imprecision due to the small number of participants that presented the outcome (less than 400)

c. We rated down two levels for methodological limitations, since two of the three RCTs had a high risk of bias in the overall judgment, and the other one had some concerns

d. We rated down one level for indirectness, since the RCTs differ in terms of duration of intervention and in how outcomes were measured.

Sunscreen use was assessed in three studies [24, 28, 29], but was measured in different forms, so meta-analysis could not be performed. Of these studies, only Armstrong found a statistically significant benefit [29]. This study had a shorter follow-up (six weeks versus 4–5 months in the other two studies), a smaller population (70 versus 358–535 in the other two studies), but it used a more objective measurement of the sunscreen use: sending a message to the study central when the cap of the container of sunscreen was removed by the participant, while the other studies just assessed the self-report of sunscreen use. However, this result had a very low certainty of evidence (Table 3).

Composite sun protection habits were assessed in two studies [26, 28]. One of them used sun protection habits index claims (score range 1–4) and found no difference at three months of follow-up, but found a slight difference at 12 months (2.63 vs 2.50 on average). The other study did not find differences in the assessed outcomes (wearing a hat, seeking shade, or using skimpy clothing). This result had a very low certainty of evidence (Table 3).

Additionally, we found other outcomes that were not included in the Summary of Findings (Table 3): having a sunburn, number of sunburns, UV radiation exposure behaviors, wearing a hat, skin self-examination, attempted suntan, believe about risk of cancer, usually/always seeking shade, usually/always wearing skimpy clothes and adherence of sunscreen application. Only the UV radiation exposure behaviors and adherence to sunscreen application showed little differences between groups. The outcome effects are presented in Table 2.

Discussion

Summary of the results

We found five RCTs, all of them were performed in the United States or Australia. Studies had high variability in terms of interventions, control groups, assessed outcomes, and follow-up period. In the overall assessment, four studies had a high risk of bias and one study had some concerns.

We only could meta-analyze one outcome (having a sunburn anytime during the follow-up), in which we did not find a statistically significant effect. Among the three studies that assessed sunscreen use, only one had a statistically significant effect (the one with the lowest population). Among the two studies that assessed a composite score of sun protection habits, one did not find an effect while the others find a small statistically significant difference. The certainty of the evidence was very low for these outcomes. Altogether, these studies do not show compelling evidence of any beneficial effect of text message reminders.

Previous systematic reviews

Although we did not find previous systematic reviews that have assessed the effects of SMS for sun protection habits, we found two previous systematic reviews that have assessed similar questions.

The first systematic review [11] assessed the effectiveness of SMS text reminders and similar electronic technology interventions to promote skin cancer prevention. This review describes the results of its included studies without performing any meta-analysis and concluded that there was a lack of effect of their assessed interventions in skin cancer prevention outcomes. This conclusion is similar to ours, although our systematic review only included studies that have assessed SMS, and our outcome definition was broader.

The second systematic review [12] explored the effectiveness of SMS text reminders and mobile applications to improve adherence to preventive behaviors (sun protection, mental attention, the continuation of contraceptive pills, the use of condoms, among others) in adolescents. It included experimental and pre-post studies and did not formulate a clear conclusion regarding SMS for sun protection habits.

Characteristics of SMS text reminders

Personalization of the SMS content is an important element to ensure the engagement with the intervention [30], since it may influence the attitudes, motivation, and attention of the participants [31]. Among our included studies, two studies (Darlow and Gold) [25, 28] developed the intervention messages using focus group feedback, while the Youl study [26] collected a pilot survey to estimate the participants’ preferences of the SMS text messages content.

For tailoring, two studies (Darlow and Duffy) [24, 25] used the health belief model profile of their participants to create the messages. The health belief model profile consists of four constructs: perceived susceptibility to ill-health, perceived severity of ill-health, perceived benefits of behavior change, and perceived barriers to taking action [32]. Since these psychological aspects can influence the participant’s perception of the message, tailored messages using the health belief model profile are thought to have a greater impact.

In the included studies, the frequency of SMS ranged from every day to weekly. Although there are no uniform recommendations regarding this topic, some authors have proposed that high-frequency interventions (at least five SMS per week) or tailored frequency could be suitable [33, 34].

However, since the studied intervention and the outcome assessment in our systematic review were very heterogeneous, we could not assess the efficacy of health-belief-model tailored SMS or intervention frequency/duration. Future research is needed in order to evaluate and compare these hypotheses.

Implications for practice

In order to describe the rationale for going from evidence to recommendation, we have assessed the criteria suggested by GRADE: balance of desirable and undesirable outcomes, feasibility, resource use, and certainty of evidence [35].

Regarding the balance of desirable and undesirable outcomes, we found no benefit for sunburn and contradictory results for sunscreen use and sun protection habits. In addition, SMS text reminders may have some potential harms that were not assessed in the included studies, such as excessive discomfort, fear, anxiety, or great decrease of sun exposure in susceptible participants which could alter their metabolism (which, although rare, is possible) [36]. For example, a study in 3,194 Danish found that seeking shade and wearing protective clothing was significantly associated with lower vitamin D levels in adults [37], and an analysis of a representative survey in USA (US National Health and Nutrition Examination Survey 2003–2006) found that staying in the shade and wearing long sleeves were significantly associated with lower 25(OH)D levels, especially in individuals who reported frequent use of shade on sunny days [38].

Regarding feasibility, a high percentage of people from developed countries have a mobile phone: 86.2% of Canadian inhabitants in 2015 [39], 95% inhabitants of the United States in 2013 [40], and 94% of Australian inhabitants in 2018 [41].

Regarding resource use, systematic reviews of economic evaluations of text messaging interventions found no comprehensive evidence [42, 43]. Particularly, cost studies of SMS reminders for improving sun protection habits are needed [33], such as those performed in SMS interventions for other topics such as diabetes mellitus prevention [44], improvement of antiretroviral therapy adherence [45], and smoking cessation [46].

Regarding the certainty of the evidence, the very low certainty of our results suggests that well-designed RCTs are needed in order to provide reliable estimates. However, researchers must reflect on the need for performing more studies using SMS, since it could be descending in favor of other messengers like WhasApp. On the other hand, nowadays the ubiquitous use of smartphones may allow to use other tools such as ad-hoc mobile applications (which allows face-to-face interactions, a more friendly interaction, and using videos/images) or messengers like WhatsApp (which allows including pictures, videos, audio information) [47, 48]. Given these alternatives, maybe studies using SMS should be limited to those contexts where smartphones use is still low.

Altogether (no clear benefits and unmeasured potential harms, lack of cost data, and very low certainty of the evidence; although high feasibility), SMS interventions use could not be recommended for improving sun protection habits.

Limitations

Since the search was only performed in three databases, we might not have found all published studies. However, we manually searched potential studies for inclusion in the references of the included studies and searched for studies that cited our included studies in Google Scholar; which could ensure that all relevant studies are included, even those from grey literature. Moreover, it has been evidenced that adding more databases to PubMed just increases the number of trials in 2.4% [49], and in most cases, it does not change the conclusion of the review [50].

Additionally, the body of evidence presents important limitations: 1) the studies are heterogeneous in several aspects, such as the follow-up period (varies between one month and 12 months), which difficult the comparability of their results. In fact, the performed meta-analysis pooled the result of a 5-months follow-up with the result of a 12-months follow-up. 2) Most of the outcomes were not measured in the same way. 3) Most studies measured outcomes as self-report, introducing a recall bias. 4) The studies had a high risk of bias or some concerns in several domains. 5) Overall, the certainty of the evidence was low in the main outcomes, mainly due to the risk of bias, inconsistency, and small sample size.

Conclusion

In conclusion, we found five RCTs with high variability in terms of interventions, control groups, assessed outcomes, and follow-up time. The meta-analysis performed showed no difference in sunburn anytime during follow-up and contradictory results were seen for sunscreen use and sun protection habits (very low certainty of the evidence). High-quality studies and cost information are needed to conclude regarding the balance of desirable and undesirable outcomes.

PRISMA 2009 checklist.

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Search strategy.

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Studies that were evaluated in full-text, and were excluded.

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Study characteristics of individual studies, in detail.

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3 Dec 2019

PONE-D-19-24279

Text message reminders for improving sun protection habits: a systematic review

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Additional Editor Comments (if provided):

Abstract – why could results not be meta-analysed?

Need to update PROSPERO page

Please remove HBM acronym

Methods

Statistical analysis – this section needs correcting – lines 114-115 – “We present our results using mean differences (MD), risk ratios (RR), odds ratios (OR), and, when we meta-analyzed results from different studies for the same outcome that were measured using different scales, standardized mean differences (SMD).”

Meta-analysis was not SMD, but combined RR, MD and RR are not presented in the table only percentages for intervention and control groups or odds ratios – please be consistent and calculate OR for each outcome for each study to allow the reader to make comparisons. Be clear whether OR were adjusted or unadjusted.

Lines 117-118: There was only one outcome which was meta-analysed. Were these methods on use of repeated measures used? It looks like it wasn’t as the outcome in Table 3 is “Sunburn anytime during follow-up (follow-up: from 5 to 12 months)”. Please ensure that the methods reflect exactly what you did in the analysis and how it was reported.

Results

Was Darlow’s study actually excluded? If results were not considered to be reliable and were not used then it should be excluded and should not appear in Tables 2 & 3, the flow chart or anywhere else in the text or abstract. If you do choose to include it, then please be clear about the reasons for this.

There is a lot of information in Table 2 – it would be helpful if the main points were summarised in the text.

p-values should be included in Table 2

Overall did text messages improve outcomes or not.

Consider a table with positive outcomes in green, negative in red and non-significant left white

Or a forest plot showing direction of effect and significance for each outcome without any pooling of data to give a visual picture of whether the intervention may be beneficial

Discussion

This needs more structure. Please provide quantitative results in the summary paragraph to report effect size and p-value. Please also clearly state the other outcomes reviewed and clarify that there was no compelling evidence to suggest that text messaging resulted in any improvements.

In the “Previous systematic reviews” section, please compare the outcomes assessed and findings of these reviews with those in the current study. What does this review offer over and above the previous reviews.

A limitations section is needed and needs to include the low quality of evidence, small numbers of studies and heterogeneity in outcome reporting.

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Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This is an interesting systematic review that examined the evidence for text messaging as an intervention to promote adherence to sun protection strategies. Below are concerns/comments for the authors to consider.

- The authors should clarify in the abstract and the methods section if they followed reporting guidelines, such as PRISMA, or other guidelines. Include appropriate citations as well.

- Introduction section, to support the rationale for the review, the authors should include additional recent promising evidence that support feasibility, acceptability and efficacy of digital interventions for behavior change (References - PMID: 30026178; PMID: 25803705; PMID: 28506955; PMID: 26831740; PMID: 28428157; PMID: 26701961; PMID: 29273573).

- Results, the authors should include much more details for the included studies, such as age, gender, study settings, follow up, outcomes, intervention details, and other RCT related factors (blinding, randomization, etc.). Similar details should be also added to Table 1.

- All the figures are fuzzy and unclear. Replace with more clear ones.

- Discussion, the authors should expand and elaborate more on how their findings support or contrast available literature and provide suggestions for future research directions that would address existing knowledge gaps.

- Discussion, it is critical to discuss the value of including direct patients' input in the development of mhealth interventions and other key considerations for end users should be sought early on in the process of app or digital behavioral intervention design to ensure long and short term engagement (PMID: 29273573; PMID: 26844685; PMID: 27966189; PMID: 28241759).

- Discussion, the authors should also acknowledge the lack of economic data to support the use of mhealth behavioral interventions to date (PMID: 27780795; PMID: 28152012).

Reviewer #2: The manuscript describes conduct and results of a systematic review of RCTs adressing the effect of SMS text reminders in promoting sun protection measures. Overall, the manuscript represents sound work.

Specific comments:

- l. 50-52: Avoidance of exposure during peak UV hours around solar noon is mentioned by all guidelines promoting sun protection and should be included in the list of sun protection habits.

- l. 53: There are a lot more studies evaluating compliance with recommendations for sun protection. You should add recent papers (e.g. Vogel et al. Cancer Epidemiol Biomarkers Prev 2017, Barkin et al. JAAD 2016, Gefeller et al. Int J Environ Res Public Health 2016).

- l. 73: If the protocol has been developed using PRISMA-P, then this should be mentioned here. Additionally, adherence to PRISMA in reporting the systematic review should also be acknowledge here.

- l. 78: Restricting the search to three databases (PubMed, Cochran, Scopus) only poses some risk of missing relevant studies. You should give an explanation why such a restricted search strategy has been adopted and discuss it as a limitation.

- l. 112ff: You should only describe what you have actually done and not what you would have done. Only for one outcome you could perform a "mini" meta-analysis summarizing two studies and reporting a combined risk ratio. I did not find any (standardized) mean differences or odds ratios among the results that have been announced in your statistics section.

- l. 123: typo I^2 statistics (not statistical)

- l. 159-161: The decision to omit data from Darlow et al.'s study because "their declared p-values did not match the declared effects" implies a serious attack towards the integrity of Darlow et al.'s study publication. Did you contact the authors for clarification? You have to give more details on this issue. The reader must have the opportunity to understand your decision better.

- l. 170: shorter follow-up (instead of lower)

- l. 171: smaller population (instead of lower)

- l. 184: Your statement that "each study had a low risk of bias" contradicts what you have said before.

- l. 219: To my opinion "clinical practice" is the wrong term here, you should delete "clinical".

- l. 226/7: Changes of metabolism is a minor thread, reduction of vitamin D production is more relevant.

- l. 227: I guess you mean possible instead of feasible.

- l. 235: "utilization of mobile phones is lower" instead of "this may be a little lower".

General: You should add a section in the discussion commenting on the limitations of your systematic review (only RCTs, search restricted to only three databases, deletion of one study for data extraction, no meta-analysis for most outcomes etc.). You should also extend your discussion by reflecting on the future. Do you really think that further high-quality on this issue are needed (as you stated in your conlusion)? Use of text messaging via SMS is descending in all developed countries. There are better ways to reach individuals on the population level in order to promote sun protection (e.g. via messengers like Whats App that allow including pictures, videos, audio information or using smartphone apps).

**********

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Reviewer #1: Yes: Sherif M Badawy

Reviewer #2: No

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15 Jan 2020

Dear editor,

We appreciate very much the comments raised by you and the reviewers. Next, we will answer to each one:

Additional Editor Comments

E1C1: Abstract – why could results not be meta-analyzed?

We added an explanation regarding this topic in the Abstract as following: “however, they could not be meta-analyzed because outcomes were measured differently across studies”.

E1C2: Need to update PROSPERO page

We requested the update of the stage of this review in the PROSPERO page (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=91661). We requested a Yes in the Completed stage of the Preliminary searches, Piloting of the study selection process, Formal screening of search results against eligibility criteria, Data extraction, Risk of bias (quality) assessment, and Data analysis.

E1C3: Please remove HBM acronym

HBM acronym is not present in the abstract of the study.

E1C4: Methods

Statistical analysis – this section needs correcting – lines 114-115 – “We present our results using mean differences (MD), risk ratios (RR), odds ratios (OR), and, when we meta-analyzed results from different studies for the same outcome that were measured using different scales, standardized mean differences (SMD).”

Meta-analysis was not SMD, but combined RR, MD and RR are not presented in the table only percentages for intervention and control groups or odds ratios – please be consistent and calculate OR for each outcome for each study to allow the reader to make comparisons. Be clear whether OR were adjusted or unadjusted.

Lines 117-118: There was only one outcome which was meta-analyzed. Were these methods on use of repeated measures used? It looks like it wasn’t as the outcome in Table 3 is “Sunburn anytime during follow-up (follow-up: from 5 to 12 months)”. Please ensure that the methods reflect exactly what you did in the analysis and how it was reported.

As the editor states, in the methods section we detailed all the statistical analysis that we intended to perform before collecting the data (including what could happen with ORs, RRs, and SMDs). However, at the end we only performed one meta-analysis using RRs. In order to avoid confusion, we now only mention the statistical analysis that we are performing. This is stated in the Statistical analysis section of the Methods, as following:

“For each outcome of each study, we calculated and reported the intervention effects as mean differences (MDs) or risk ratios (RRs) along with their 95% confidence intervals (95% CIs).

When two or more studies presented the same outcome in a similar fashion, we performed a meta-analysis using random-effects models (Mantel-Haenszel method) due to heterogeneity across studies interventions (22). Meta-analyses were performed using Review Manager Software Version 5.3.

We assessed heterogeneity using the I2 statistics, and we considered that heterogeneity might not be important when I2 < 40% (23). Publication bias was not assessed since the number of studies pooled for each meta-analysis was lesser than ten (23).”.

Also, as the reviewer recommends, we added the RRs and MDs for each study to the Table 2 (Outcomes effects) in order to facilitate the reading of the results. We declared that these RRs and MDs were unadjusted at the bottom of the Table 2 (sentence: The risk ratios (RRs) and mean differences (MDs) were unadjusted).

E1C5: Was Darlow’s study actually excluded? If results were not considered to be reliable and were not used then it should be excluded and should not appear in Tables 2 & 3, the flow chart or anywhere else in the text or abstract. If you do choose to include it, then please be clear about the reasons for this.

The Darlow’s study presents results for the comparison of interest. However, the paper does not bring enough information regarding their results (they only present ANOVA F-test results for several groups, but not for the comparison of interest in our systematic review). We have mailed the authors asking for the results without any answer.

Since we are performing a comprehensive systematic review, we think that all studies that answer our question should be named, regardless of their omissions or lack of clarity. So, we are still showing its characteristics in table 1.

However, for table 2 (results of the studies), we now only mention the following: “The paper does not bring enough information in order to present its results”.

E1C6: There is a lot of information in Table 2 – it would be helpful if the main points were summarised in the text.

p-values should be included in Table 2

We agree that data of statistical inference of each study is helpful for the readers. Thus, we have calculated the effect measures (MDs or RRs) and their 95% confidence intervals whenever possible (Table 2). We think that those measures are more useful than p-values for inference interpretation, and since this table is overloaded, we decided not to include p-values.

E1C7: Overall did text messages improve outcomes or not.

Consider a table with positive outcomes in green, negative in red and non-significant left white

Or a forest plot showing direction of effect and significance for each outcome without any pooling of data to give a visual picture of whether the intervention may be beneficial

In order to clarify the results of the included studies, we now present in Table 2 the RRs and MDs, and write in bold the statistically significant results.

E1C8: This needs more structure. Please provide quantitative results in the summary paragraph to report effect size and p-value. Please also clearly state the other outcomes reviewed and clarify that there was no compelling evidence to suggest that text messaging resulted in any improvements.

As suggested by the editor, we added the following lines showing the quantitative results in the Summary of the results section of the discussion:

“We only could meta-analyze one outcome (having a sunburn anytime during the follow-up), in which we did not find a statistically significant effect. Among the three studies that assessed sunscreen use, only one had a statistically significant effect (the one with the lowest population). Among the two studies that assessed a composite score of sun protection habits, one did not find an effect while the others find a small statistically significant difference. The certainty of the evidence was very low for these outcomes. Altogether, these studies do not show compelling evidence of any beneficial effect of text message reminders.”

E1C9: In the “Previous systematic reviews” section, please compare the outcomes assessed and findings of these reviews with those in the current study. What does this review offer over and above the previous reviews.

Thanks for this comment. We added the following lines to give more information regarding the previous reviews and delineate some comparisons, in the “Previous systematic reviews” section of the discussion:

Although we did not find previous systematic reviews that have assessed the effects of SMS for sun protection habits, we found two previous systematic reviews that have assessed similar questions.

The first systematic review (11) assessed the effectiveness of SMS text reminders and similar electronic technology interventions to promote skin cancer prevention. This review describes the results of its included studies without performing any meta-analysis, and concluded that there was a lack of effect of their assessed interventions in skin cancer prevention outcomes. This conclusion is similar to ours, although our systematic review only included studies that have assessed SMS, and our outcome definition was broader.

The second systematic review (12) explored the effectiveness of SMS text reminders and mobile applications to improve adherence to preventive behaviors (sun protection, mental attention, the continuation of contraceptive pills, the use of condoms, among others) in adolescents. It included experimental and pre-post studies and did not formulate a clear conclusion regarding SMS for sun protection habits.

E1C10: A limitations section is needed and needs to include the low quality of evidence, small numbers of studies and heterogeneity in outcome reporting.

Thanks for this comment. We added the following paragraphs about Limitations:

“A possible limitation of this review is that search was performed in only three databases, which could cause that not all published studies were found. However, we manually searched potential studies for inclusion in the references of the included studies and also searched for studies that cited our included studies in Google Scholar; which could ensure that all relevant studies are included, even those from grey literature. Moreover, it has been evidenced that adding more databases to PubMed just increases the number of trials in 2.4% (49), and in most cases, it does not change the conclusion of the review (50).

Additionally, the body of evidence presents important limitations: 1) the studies are heterogeneous in several aspects, such as the follow-up period (varies between one month and 12 months), which difficult the comparability of their results. In fact, the performed meta-analysis pooled the result of a 5-months follow-up with the result of a 12-months follow-up. 2) Most of the outcomes were not measured in the same way. 3) Most studies measured outcomes as self-report, introducing a recall bias. 4) The studies had a high risk of bias or some concerns in several domains. 5) Overall, the certainty of the evidence was low in the main outcomes, mainly due to the risk of bias, inconsistency, and small sample size.

Reviewer 1:

R1C1: This is an interesting systematic review that examined the evidence for text messaging as an intervention to promote adherence to sun protection strategies. Below are concerns/comments for the authors to consider.

Thank you very much for your kind words.

R1C2: The authors should clarify in the abstract and the methods section if they followed reporting guidelines, such as PRISMA, or other guidelines. Include appropriate citations as well.

&

R2C4: l. 73: If the protocol has been developed using PRISMA-P, then this should be mentioned here. Additionally, adherence to PRISMA in reporting the systematic review should also be acknowledge here.

Thank you for the comments. We added the following sentence in the Abstract: We performed a systematic search in PubMed, Central Cochrane Library, and Scopus, following the PRISMA recommendations to perform systematic reviews.

We also added the following sentence in the Methods section: We performed a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) recommendations (19).

R1C3: Introduction section, to support the rationale for the review, the authors should include additional recent promising evidence that support feasibility, acceptability and efficacy of digital interventions for behavior change (References - PMID: 30026178; PMID: 25803705; PMID: 28506955; PMID: 26831740; PMID: 28428157; PMID: 26701961; PMID: 29273573).

Thank you for the comments. We added the following lines in the second paragraph of the Introduction citing the suggested literature:

“In this way, there is a growing interest in technology-based interventions, such as the use of mobile applications (8), electronic mails (9) and short message service text message reminders (SMS text reminders) (10, 11). There are some systematic reviews that have synthetized the evidence of the effects of SMS text reminders and mobile applications in medication adherence and management in adolescents (12-14) and adults (15), supporting their feasibility and acceptability. Nevertheless, all of those reviews recommended future studies with a more fitting design.”

R1C4: Results, the authors should include much more details for the included studies, such as age, gender, study settings, follow up, outcomes, intervention details, and other RCT related factors (blinding, randomization, etc.). Similar details should be also added to Table 1.

We added the suggested information in:

- Characteristics section (Results):

o “Regarding the population characteristics, three studies (27-29) were performed in community dwellers; the female proportion ranged from 8.4% to 100%, and the mean age ranged from 31.6 to 44.2 years.

o Regarding the intervention, it consisted on delivering SMS text reminders on sun protection habits, such as sunscreen use and skin self-examination, with heterogeneous frequency (range: three to seven days) and duration (range: one to 12 months). Of the five RCTs, two of them tailored the messages according to baseline characteristics of participants, using the health belief model (HBM) constructs (24, 25).”

- Risk of bias section (Results):

o “Regarding the randomization process, three studies had some concerns, while three studies had high risk of bias in the measurement of the outcome. Only one study had low risk of bias in most domains (29). Four studies had high risk of bias in the overall judgment (Figure 2).”

- Outcome effects (Results):

o “Several objective outcomes were reported by the included studies. Some of them were the number of sunburns, sunscreen use, sun protection habits (protecting clothes, wearing sunglasses, wearing a hat, etc.), skin self-examination, attempted suntan and adherence rate of sunscreen application.”

We are reporting the results of the included studies in Table 2. And we also added the suggested variables in the Table 1: study settings, follow-up period, and intervention details.

R1C5: All the figures are fuzzy and unclear. Replace with more clear ones.

We apologize for it. We are submitting all the three figures in JPG format.

R1C6: Discussion, the authors should expand and elaborate more on how their findings support or contrast available literature and provide suggestions for future research directions that would address existing knowledge gaps.

The comparison with previous literature has been improved, as detailed in the answer to E1C9.

To provide suggestion for future research directions, we added the following in the “implications for practice” section of the discussion:

“However, researchers must reflect on the need for performing more studies using SMS, since it could be descending in favor of other messengers like WhasApp. On the other hand, nowadays the ubiquitous use of smartphones may allow to use other tools such as ad-hoc mobile applications (which allows face-to-face interactions, a more friendly interaction, and using videos/images) or messengers like WhatsApp (which allows including pictures, videos, audio information) (47, 48). Given these alternatives, maybe studies using SMS should be limited to those contexts where smartphones use is still low.”

R1C7: Discussion, it is critical to discuss the value of including direct patients' input in the development of mhealth interventions and other key considerations for end users should be sought early on in the process of app or digital behavioral intervention design to ensure long and short term engagement (PMID: 29273573; PMID: 26844685; PMID: 27966189; PMID: 28241759).

Thank you for suggesting literature to cite. We added the following lines to discuss the participants’ input in the Characteristics of SMS text reminders section:

“Personalization of the SMS content is an important element to ensure the engagement with the intervention (30), since it may influence the attitudes, motivation, and attention of the participants (31). Among our included studies, two studies (Darlow and Gold) (25, 28) developed the intervention messages using focus group feedback, while the Youl study (26) collected a pilot survey to estimate the participants’ preferences of the SMS text messages content.

For tailoring, two studies (Darlow and Duffy) (24, 25) used the HBM profile of their participants to create the messages. The HBM profile consists of four constructs: perceived susceptibility to ill-health, perceived severity of ill-health, perceived benefits of behavior change, and perceived barriers to taking action (32). Since these psychological aspects can influence the participant’s perception of the message, tailored messages using the HBM profile are thought to have a greater impact.”

Moreover, we added a column to describe the Participants’ input in the Supplementary material 3.

R1C8: Discussion, the authors should also acknowledge the lack of economic data to support the use of mhealth behavioral interventions to date (PMID: 27780795; PMID: 28152012).

We agree with the reviewer, and accordingly we have added the following lines in the “Implications for practice” section:

“Regarding resource use, systematic reviews of economic evaluations of text messaging interventions found no comprehensive evidence (42, 43). Particularly, cost studies of SMS reminders for improving sun protection habits are needed (33), such as those performed in SMS interventions for other topics such as diabetes mellitus prevention (44), improvement of antiretroviral therapy adherence (45), and smoking cessation (46).”

Reviewer 2:

R2C1: The manuscript describes conduct and results of a systematic review of RCTs adressing the effect of SMS text reminders in promoting sun protection measures. Overall, the manuscript represents sound work.

Thank you very much.

R2C2: l. 50-52: Avoidance of exposure during peak UV hours around solar noon is mentioned by all guidelines promoting sun protection and should be included in the list of sun protection habits.

Thank you for the recommendation. We included the phrase “avoidance of exposure during peak UV hours around solar noon” in the first paragraph of Introduction.

R2C3: l. 53: There are a lot more studies evaluating compliance with recommendations for sun protection. You should add recent papers (e.g. Vogel et al. Cancer Epidemiol Biomarkers Prev 2017, Barkin et al. JAAD 2016, Gefeller et al. Int J Environ Res Public Health 2016).

Thank you for suggesting references. We added the following sentence in the first paragraph of Introduction:

“Accordingly, educational interventions to enhance compliance with sun protection habits have been proposed, and considerable effects have been observed in certain groups, such as melanoma survivors, parents of young children, and medical professionals (4-6).”

R2C5: l. 78: Restricting the search to three databases (PubMed, Cochran, Scopus) only poses some risk of missing relevant studies. You should give an explanation why such a restricted search strategy has been adopted and discuss it as a limitation.

We agree that this could be a limitation of our study. So, we have added the following paragraph to the limitations section of the discussion:

“A possible limitation of this review is that search was performed in only three databases, which could cause that not all published studies were found. However, we manually searched potential studies for inclusion in the references of the included studies and also searched for studies that cited our included studies in Google Scholar; which could ensure that all relevant studies are included, even those from grey literature. Moreover, it has been evidenced that adding more databases to PubMed just increases the number of trials in 2.4% (49), and in most cases, it does not change the conclusion of the review (50).”

R2C6: l. 112ff: You should only describe what you have actually done and not what you would have done. Only for one outcome you could perform a "mini" meta-analysis summarizing two studies and reporting a combined risk ratio. I did not find any (standardized) mean differences or odds ratios among the results that have been announced in your statistics section.

We agree with this commentary, and we have simplified our statistical analysis section accordingly, as detailed in the answer to E1C4.

R2C7: l. 123: typo I^2 statistics (not statistical)

Thank you for the correction. We are now using the term “I2 statistics” in the methods section

R2C8: l. 159-161: The decision to omit data from Darlow et al.'s study because "their declared p-values did not match the declared effects" implies a serious attack towards the integrity of Darlow et al.'s study publication. Did you contact the authors for clarification? You have to give more details on this issue. The reader must have the opportunity to understand your decision better.

The Darlow’s study presents results for the comparison of interest. However, the paper does not bring enough information regarding their results (they only present ANOVA F-test results for several groups, but not for the comparison of interest in our systematic review). We have mailed the authors asking for the results without any answer.

Since we are performing a comprehensive systematic review, we think that all studies that answer our question should be named, regardless of their omissions or lack of clarity. So, we are still showing its characteristics in table 1.

However, for table 2 (results of the studies), we now only mention the following: “The paper does not bring enough information in order to present its results”

R2C9: l. 170: shorter follow-up (instead of lower)

Thank you for the correction. We are now using the phrase “shorter follow-up”.

R2C10: l. 171: smaller population (instead of lower)

Thank you for the correction. We are now using the term “smaller population”.

R2C11: l. 184: Your statement that "each study had a low risk of bias" contradicts what you have said before.

Thank you for the correction. We replaced that sentence with the following one in Summary of the results section (Discussion): In the overall assessment, four studies had a high risk of bias and one study had some concerns.

R2C12: l. 219: To my opinion "clinical practice" is the wrong term here, you should delete "clinical".

Thank you for the correction. We are now using the phrase “Implications for practice”.

R2C13: l. 226/7: Changes of metabolism is a minor thread, reduction of vitamin D production is more relevant.

Thank you for this important observation. We added the following lines in the second paragraph of Implications for practice section:

“For example, a study in 3,194 Danish found that seeking shade and wearing protective clothing was significantly associated with lower vitamin D levels in adults (37), and an analysis of a representative survey in USA (US National Health and Nutrition Examination Survey 2003–2006) found that staying in the shade and wearing long sleeves were significantly associated with lower 25(OH)D levels, especially in individuals who reported frequent use of shade on sunny days (38).”

R2C14: l. 227: I guess you mean possible instead of feasible.

Thank you for the correction. We are now using the term “possible”.

R2C15: l. 235: "utilization of mobile phones is lower" instead of "this may be a little lower".

Thank you for the correction. We are now using the phrase “utilization of mobile phones is lower”.

R2C16: General: You should add a section in the discussion commenting on the limitations of your systematic review (only RCTs, search restricted to only three databases, deletion of one study for data extraction, no meta-analysis for most outcomes etc.).

We have added a paragraph on the limitations section of the discussion regarding this topic:

“Additionally, the body of evidence presents important limitations: 1) the studies are heterogeneous in several aspects, such as the follow-up period (varies between one month and 12 months), which difficult the comparability of their results. In fact, the performed meta-analysis pooled the result of a 5-months follow-up with the result of a 12-months follow-up. 2) Most of the outcomes were not measured in the same way. 3) Most studies measured outcomes as self-report, introducing a recall bias. 4) The studies had a high risk of bias or some concerns in several domains. 5) Overall, the certainty of the evidence was low in the main outcomes, mainly due to the risk of bias, inconsistency, and small sample size.”

R2C17: You should also extend your discussion by reflecting on the future. Do you really think that further high-quality on this issue are needed (as you stated in your conlusion)? Use of text messaging via SMS is descending in all developed countries. There are better ways to reach individuals on the population level in order to promote sun protection (e.g. via messengers like Whats App that allow including pictures, videos, audio information or using smartphone apps).

Thank you for the observation, this is definitely an important issue to be discussed. Accordingly, we have added the following lines in the Implications for practice section of the discussion:

“However, researchers must reflect on the need for performing more studies using SMS, since it could be descending in favor of other messengers like WhasApp. On the other hand, nowadays the ubiquitous use of smartphones may allow to use other tools such as ad-hoc mobile applications (which allows face-to-face interactions, a more friendly interaction, and using videos/images) or messengers like WhatsApp (which allows including pictures, videos, audio information) (47, 48). Given these alternatives, maybe studies using SMS should be limited to those contexts where smartphones use is still low.”

Submitted filename: respuesta.docx

Click here for additional data file.

26 Feb 2020

PONE-D-19-24279R1

Text message reminders for improving sun protection habits: a systematic review

PLOS ONE

Dear Dr Taype-Rondan,

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Academic Editor

PLOS ONE

Additional Editor Comments (if provided):

There are still some minor points which need to be revised before this paper is suitable for publication:

Please update PROSPERO – it still says only preliminary searches have been conducted.

Please remove HBM acronym throughout the article. This acronym is unnecessary

Statistical analysis section:

Change ..” lesser than ten” to “less than ten”

Results:

Please include reference numbers for each of the studies in tables 1-3.

Change title of table 2 to: Characteristics of included studies

Limitations:

Incorrect grammar: “A possible limitation of this review is that search was performed in only three databases, which could cause that not all published studies were found.”

Typo: “...such es the follow-up period”

We recommend asking a native English speaker to proofread the article.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

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Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

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Reviewer #1: Yes

Reviewer #2: Yes

**********

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Reviewer #1: Yes

Reviewer #2: No

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The authors addressed all my earlier concerns. No additional comments. This review contributes to existing literature on tech-based behavioral interventions.

Reviewer #2: Final proofreading of the text should be done by a native speaker who can correct language errors.

**********

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Reviewer #1: Yes: Sherif M Badawy

Reviewer #2: No

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9 Mar 2020

attached

Submitted filename: respuesta.docx

Click here for additional data file.

12 Mar 2020

PONE-D-19-24279R2

Text message reminders for improving sun protection habits: a systematic review

PLOS ONE

Dear Dr Taype-Rondan,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Specifically to correct the English. We recommend that the paper is proof-read by a native English speaker.

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We look forward to receiving your revised manuscript.

Kind regards,

Jennifer A Hirst, DPhil

Academic Editor

PLOS ONE

Additional Editor Comments (if provided):

The English is still poor. Please change: "Due to the fact that search was only performed in three databases, we might not found all published studies" to "Due to the fact that search was only performed in three databases, we might not have found all published studies."

[Note: HTML markup is below. Please do not edit.]

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files to be viewed.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email us at figures@plos.org. Please note that Supporting Information files do not need this step.

27 Mar 2020

Dear editor,

We appreciate very much the comments raised by you and the reviewers. We are answering to each one in the attached file.

Submitted filename: respuesta 4.docx

Click here for additional data file.

1 May 2020

Text message reminders for improving sun protection habits: a systematic review

PONE-D-19-24279R3

Dear Dr. Taype-Rondan,

We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements.

Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication.

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With kind regards,

Jennifer A Hirst, DPhil

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

7 May 2020

PONE-D-19-24279R3

Text message reminders for improving sun protection habits: a systematic review

Dear Dr. Taype-Rondan:

I am pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please notify them about your upcoming paper at this point, to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

For any other questions or concerns, please email plosone@plos.org.

Thank you for submitting your work to PLOS ONE.

With kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Jennifer A Hirst

Academic Editor

PLOS ONE