Pretravel plans and discrepant trip experiences among travelers attending a tertiary care centre family travel medicine clinic.

BACKGROUND: International travel can expose travelers to a number of health risks. Pretravel consultation (PC) helps mitigate risk and prepare travelers for health concerns that might arise. The assessment of risk, mitigation strategies, and relevance of pretravel advice is dependent on how closely travelers adhere to their planned travel itinerary and activities. We determined the proportion of returned travelers whose completed travel experiences differed from their stated travel itineraries, and identified discrepancies that significantly altered the traveler's health risk and would have required alternative counseling during their PC.
METHODS: We conducted a prospective cohort study at the SickKids' Family Travel Clinic between October 2014 and November 2015. Returned travelers who completed a post-travel survey were included. Pretravel consultation assessments and post-trip surveys were compared to identify discrepant trip experiences.
RESULTS: A total of 389 travelers presented to the clinic for a PC during the study period and 302 (77.6%) were enrolled. Post-travel surveys were received from 119 (39.4%) participants, representing 101 unique itineraries. The median participant age was 36.3 years (IQR 26.6-47.5) and there were 73 female travelers (61%). Most participants (n = 87,73%) were healthy as well as Canadian born (n = 84, 71%). A quarter of travelers were visiting friends and relatives (VFR) (n = 30, 25.2%). The vast majority of returned travelers (n = 109, 92%) reported discrepant trip experiences involving trip duration, countries visited, accommodations, environmental surroundings and/or activities. Almost two thirds of these individuals (n = 68, 62%) would have required alternative pretravel counseling. We did not identify any demographic or planned trip characteristics that predicted discrepant trip experiences requiring alternative pretravel counseling.
CONCLUSIONS: The majority of travelers reported discrepant trip experiences and the discrepancies often affected health risk. Therefore, clinicians should consider providing broader counselling during the PC as discrepancies from planned travel are common.

Introduction

International travel can expose travelers to a number of health risks, which vary depending on the trip itinerary and individual traveler factors. While visiting a different region of the world or a specific geographic region within a country, travelers may be exposed to different mosquitoes and vector-borne diseases. Certain activities such as water activities or animal excursions may subject travelers to bodily harm that they would not encounter at home. Furthermore, travelers may engage in high-risk behaviours including unprotected sex and illicit drug use while abroad and expose themselves to additional infectious risks from sexually transmitted infections [1]. Any traveler, including people returning to their home country to visit friends and relatives (VFR) may underestimate risks associated with travel [2]. As a group, VFRs experience higher incidences of travel-related infectious diseases which is partially a result of broader risk exposures such as staying in homes and living the local lifestyle and also considering themselves immune to certain travel-related infectious diseases [2, 3]. Lastly, underlying medical conditions may predispose an individual to more severe outcomes after certain infections that are acquired abroad including malaria and salmonella.

The Pretravel Consultation (PC) offers a dedicated time to prepare travelers for health concerns that might arise during their trips. In addition to obtaining the traveler’s medical history, the PC assessment should cover details of the upcoming trip including duration of travel, reason for travel, VFR status, countries to be visited, environmental surroundings, accommodations and special activities (e.g. disaster relief, mountain climbing, diving, etc.) [3]. Clinicians working in travel clinics provide personalized pretravel advice to mitigate potential risks, by highlighting the likely exposures, reminding travelers of ubiquitous risks, and prescribing targeted interventions (such as vaccines and prophylactic medications). Their assessment is predicated on the accuracy and quality of the information provided by the traveler during the PC [4, 5]. Providing appropriate pretravel advice for travelers to adhere to is a key element in ensuring that international travelers return home in good health [6].

The relevance of the pretravel advice and preventative measures are inherently dependent on whether travelers adhere to their stated travel plans. To our knowledge, there has been no published data to date describing the frequency of discrepant trip experiences (i.e. differences between planned itineraries and actual experiences). As such, we sought to determine the proportion of returned travelers whose completed travel experiences differed from their planned itineraries and whether the discrepancies would have altered the traveler’s health risk in such a way that alternative pretravel counseling was required. In addition, we explored whether specific demographic or trip characteristics may have predicted discrepant trip experiences requiring alternative counseling. Lastly, we explored if individuals with discrepant trip experiences also endorsed partaking in high-risk behaviours. It is anticipated that this information may help guide clinicians who provide PCs.

Methods

Study site

The Hospital for Sick Children (SickKids) is Canada’s second-largest freestanding children’s hospital and is a tertiary-care center located in downtown Toronto. Toronto is one of the most diverse cities in the world with 46.1% of the city’s population being foreign-born [7]. The SickKids Family Travel Clinic was established in 2013 with the goal of providing pretravel care and recommendations to children and their families [8].

Study design

This discrepant travel experience study was conducted as part of a larger study [9] assessing risk perception and adherence to recommendations from the PC. The study, which was designed as a prospective cohort, was conducted at the SickKids Family Travel Clinic with enrollment over a 57-week period from October 2014 to November 2015. Per routine clinic practice, travelers were asked to complete a pretravel questionnaire (S1 File) prior to their initial PC, to document information about their demographics, health history, and upcoming travel plans. Individuals were approached for study consent and enrollment when the pre-travel questionnaire was distributed. Those who provided consent to participate in the discrepant travel experience portion of the study were contacted by e-mail and invited to complete an online post-travel survey about their actual travel experience and engagement in any high-risk behaviours (S2 File). The online survey request was sent out 1 week post-travel via an online questionnaire administered through REDCap. If the survey was not completed, an initial email reminder was sent 48hr after the original message, and then a phone call reminder was provided 48 hours thereafter. If after an additional 48 hours the survey was not completed, the participants were called and a trained research assistant administered the survey over the phone. The study protocol was approved by the SickKids Research Ethics Board, (REB no. 1000045900).

Study participants

This study included individuals who attended the SickKids Family Travel Clinic for their initial PC and who completed the online post-travel survey. We excluded hospital employees and those who planned to travel for longer than 1 year. Consent for participation was obtained over the phone or in-person at the PC.

Data collection

All patients who completed both the pretravel questionnaire and post-travel survey were included in the analysis. The PC questionnaires were reviewed for demographic and medical history information, as well as details of the planned trip itinerary including the duration, reason for travel, countries to be visited, environmental settings to be visited, accommodations and planned activities. If a traveler indicated that they were visiting friends and/or relatives in addition to traveling for other purposes, they were categorized as a VFR. Details pertaining to the actual trip experiences were obtained from the post-travel surveys. If participants were traveling together with the same itinerary (i.e. belonging to the same traveling unit, including families and other groups), their completed trip details were analyzed together. Post-travel survey responses indicating high-risk behaviours were defined as excessive alcohol consumption (exceeding national low-risk alcohol consumption guidelines [10]), recreational drug use, new tattoos or piercings, or new sexual partners during travel.

Discrepant trip experiences were defined as any difference between stated travel plans (i.e. responses from the pretravel questionnaire) and actual trip experiences (i.e. responses from the post-travel survey). Responses from the pretravel questionnaire and post-travel survey were compared for each participant. For each discrepancy, the impact on risk (i.e. higher, completely different, or lower/no change in risk) and the need for alternative pretravel counseling were defined a priori (Table 1) and based on consensus discussion between 3 authors (JKW, NN, SKM). Discrepancies needing alternative counseling included those where the change in risk was higher or completely different. If alternative counseling was required, the actual trip experience was reviewed to determine if additional vaccinations, chemoprophylaxis or other empiric medication prescriptions (e.g. for altitude sickness) would have been indicated.

Table 1

Decision algorithm for categorizing discrepancies in trip characteristics.

Variable	Discrepancy Details	Change in Risk
(Trip Characteristic)		Higher	Completely Different	Lower or No change
Trip Duration	25% or more increase in duration	X
	25% decrease in duration			X
	Discrepancy results in having needed additional/different counselling and/or intervention(s)?	Yes		No
Countries Visited (world bank income tiers)	New country (lower income tier than any pretravel country)	X
	New country (same income tier as any pretravel country OR new income tier but not lower than any pretravel countries OR new income tier and higher than any pretravel countries)			X*
• high-income
• upper-middle	Removal of country			X
• lower-middle	Discrepancy results in having needed additional/different counselling and/or intervention(s)?	Yes		No
• low-income
Accommodations	Adding: locals/family/friends, camping or safari	X
• hotel (any star)	Adding: hostel		X
• hostel	Adding: hotel, rented house/apt, and/or cruise			X
• locals/family/friends	Changing from hotel, rented house/apt or cruise ⟺ anything else	X
• rented house/apt
• camping or safari	Changing between hostel ⟺ locals/family/friends ⟺ camping or safari		X
• cruise
• other	Changing between hotel ⟺ rented house/apt ⟺ cruise			X
	Changing between: camping ⟺ safari			X
	Changing from anything ⟺ hotel or cruise alone			X
	Changing or adding “Other” (but not described)	.	.	.
	Removing anything			X
	Discrepancy results in having needed additional/different counselling and/or intervention(s)?	Yes		No
Destination	Addition: high altitude, rural/remote, jungle/forest	X
• urban	Addition: beach or urban			X
• rural or remote	Changing between: high altitude ⟺ rural/remote ⟺ jungle/forest		X
• high altitude
• beach	Removing anything			X
• jungle or forest	Discrepancy results in having needed additional/different counselling and/or intervention(s)?	Yes		No
Activities	Adding: climbing/trekking, water (snorkel, swimming or scuba), raft or boat, animals, cave, school/hospital/orphanage, motorcycle/scooter	X
• biking
• hiking
• climb/trek	Changing between: climbing/trekking ⟺ water (snorkel, swimming or scuba) ⟺ raft or boat ⟺ animals ⟺ cave ⟺ school/hospital/orphanage ⟺ motorcycle/scooter		X
• water (snorkel, swimming or scuba considered similar)
	Adding: biking, hiking, public transport			X
• raft or boat
• animals
• cave	Removing anything			X
• public transport	Discrepancy results in having needed additional/different counselling and/or intervention(s)?	Yes		No
• school/hospital/ orphanage
• motorcycle/scooter
OVERALL	Any discrepancies that results in having needed additional/different counselling and/or intervention(s)?	Yes (if any above = yes)		No (if all of above are No)

* When adding a new country within the same income tier, the new country needed to belong to the same geographical region as other countries in the itinerary to avoid introducing different infectious diseases risks

Statistical analysis

Demographic information and completed travel experiences were summarized using standard descriptive statistics. Discrepant trip experiences including those requiring alternative pretravel counseling were summarized using counts and proportions. We explored whether the following demographic or trip characteristics were associated with the need for alternative pretravel counseling: age, sex, medical comorbidities, country of birth, VFR status, region of travel, traveling alone, traveling with children, reason for travel, duration of travel, having a fixed itinerary, joining an organized tour, endorsing high-risk behaviours. Univariable analyses to determine the relationship between these characteristics and the need for alternative counseling were conducted using the Spearman’s correlation coefficient for continuous variables and chi-squared or Fisher’s exact test for dichotomous variables. An exploratory multivariable analysis was planned that included variables with a p-value of < 0.2 from the univariable analysis and using step-wise backward elimination. Statistical analyses were performed using IBM SPSS Statistics for Macintosh, Version 26.0, and p-values less than .05 were considered statistically significant.

Results

Traveler characteristics

During the study period, there were 883 visits to the SickKids Family Travel Clinic. Of the 389 individuals who were eligible for participation, 302 (77.6%) were enrolled in the parent study. Pretravel questionnaires were available for 297 (98.3%) travelers. From this cohort, 119 travelers (40%) completed the post-travel survey and were included in this study on discrepant trips (Fig 1).

Fig 1

Included participants.

+ Follow-up visits included completion of multi-dose vaccine series. * Other–reasons for ineligibility not documented.

The median age of participants meeting inclusion criteria was 36.3 years (IQR 26.6–47.5 years), and there were more females than males (n = 73, 61%). Children under the age of 18 accounted for 13% (n = 15) of participants, with 7 being under the age of 5 years. Almost all individuals (n = 112, 94%) indicated they were traveling with others, with other family members being the most common travel companion (n = 69, 58%). The majority of the travelers were born in Canada (n = 84, 71%). VFRs made up a quarter of travelers (n = 30, 25%). (Table 2)

Table 2

Demographics and planned travel characteristics of travelers at the SickKids Travel Clinic for October 2014 to November 2015.

	Completed Post-Travel Survey	Baseline Travel Survey Only
	(N = 119)	(N = 178)
	n (%)	n (%)
Age *
< 5	7 (6)	41 (23)
5–10	3 (3)	43 (24)
11–17	5 (4)	35 (20)
18–35	43 (36)	19 (11)
36–55	47 (39)	37 (21)
> 55	14 (12)	3 (2)
Mean (SD)	36.7 (16.6)	18.4 (16.9)
Median (IQR)	36.3 (26.6–47.5)	11.7 (5.4–33.0)
Gender **
Male	46 (39)	93 (52)
Female	73 (61)	85 (48)
Country of Birth
Canada	86 (72)	141 (79)
Outside of Canada
North America	3 (3)	2 (1)
Caribbean	2 (2)	0 (0)
South & Central America	4 (3)	0 (0)
Europe	8 (7)	12 (7)
Mediterranean	1 (1)	4 (2)
Africa	5 (4)	7 (4)
South Asia	3 (3)	6 (3)
Southeast Asia	2 (2)	1 (1)
Pacific	5 (4)	5 (3)
VFR **	30 (25)	67 (38)
Traveling Alone
Yes	7 (6)	4 (2)
No Details	0	1
Travel Insurance
Purchased/Intending to purchase	99 (86)	135 (82)
Not specified	4	13
Comorbidities
None	87 (73)	141 (79)
Mental health	5 (4)	6 (3)
Chronic Hepatitis	2 (2)	-
Asthma	5 (4)	5 (3)
Gastrointestinal	-	2 (1)
Dyslipidemia	4 (3)	1 (1)
Hypertension	4 (3)	3 (2)
Thyroid Condition	4 (3)	1 (1)
Musculoskeletal	4 (3)	2 (1)
Chronic Kidney Disease	-	1 (1)
Diabetes	-	2 (1)
Sickle Cell	-	1 (1)
Immunocompromised	4 (3)	6 (3)
Other	1 (1)	4 (2)
Smoker	3 (3)	2 (1)
No Details	3	6

* p < 0.001

** p <0.05

Comparatively, those who completed the post-travel survey were older (mean age 36.7 years vs. 18.4 years, p<0.001), more often female (61% vs. 46%, p < 0.05), and less likely to identify as a VFR (25% vs. 38%, p < 0.05) than those who only completed the baseline pretravel questionnaire. Two thirds of participants who did not complete the post-travel survey were children under the age of 18. Half of these pediatric participants (n = 65, 54%) belonged to a traveling unit (group or family) where at least one other member had provided a post-travel questionnaire.

Actual trip characteristics

The 119 completed surveys represented 101 unique travel itineraries (Table 3). Included among the individual respondents were 30 individuals belonging to 3 families and 10 groups. The median trip duration was 17 days (IQR 11–22) and 15 trips lasted greater than 1 month (n = 14%). The most common reasons for travel were for vacation purposes (n = 58, 57%) and visiting friends and/or relatives (n = 30, 30%). Most accommodations were hotels (n = 81, 80%); however, almost half of the trips included a stay with either locals or friends and/or families for a part of the trip (n = 40, 38%). Forty-four itineraries (44%) included multiple types of accommodations. Two-thirds of the pretravel itineraries indicated that a single country would be visited (n = 68, 67%). The most commonly visited regions were South and Central America (n = 31, 31%), Africa (n = 17, 17%) and the Caribbean (n = 17, 17%). Travelers visited a variety of settings including urban regions (n = 91, 90%), rural and/or remote regions (n = 70, 69%) and beaches (n = 67, 66%). Most individuals participated in more than one type of activity or excursion (n = 85, 71%) that could have exposed them to health risks, whereas 9 (8%) reported partaking in no activities.

Table 3

Completed trip characteristics.

	n (%)#
Unique Trip Itineraries (N = 101)
Trip Duration (Median Duration in Days, IQR)	17 (11–22)
Reason for travel (could indicate more than one)^
Vacation	58 (57)
VFR§	30 (30)
Education or Business	7 (7)
Volunteering/Humanitarianism	4 (4)
Cruise	3 (3)
Religious reasons/Pilgrimage	0 (0)
Adoption	1 (1)
Other/Not indicated	2 (2)
Long-stay travel⧧	15 (15)
Organized Tour (Yes or Partial)	44 (44)
Number of Countries Visited
1	68 (67)
2	20 (20)
3	8 (8)
4	4 (4)
5 or more	5 (5)
Regions Visited (Could choose more than one)$
Caribbean	17 (17)
South & Central America	30 (30)
Europe	1 (1)
Eastern Mediterranean	2 (2)
Africa	15 (15)
South-East Asia	10 (10)
South Asia	14 (14)
Western Pacific	12 (12)
Accommodations (Could choose more than one)
Hotel	81 (80)
Hostel	10 (10)
Locals/Friends/Family	40 (40)
Rented House/Apartment	19 (19)
Camping or Safari	12 (12)
Cruise Ship	6 (6)
Environmental Surroundings (Could choose more than one)
Urban	91 (90)
Rural/Remote	70 (69)
Beach	67 (66)
Jungle/Forest	47 (47)
High Altitude	21 (21)
Individual Travelers (N = 119)
Activities
Biking	13 (11)
Hiking (Hiking, Climbing)	59 (50)
Water Related (Snorkeling, Swimming, Scuba)	56 (47)
Boating (Boating, Rafting)	49 (41)
Contact with Animals	43 (36)
Caving	5 (4)
Public Transit	70 (59)
Visiting Schools, Hospitals or Orphanages	27 (23)
Motorcycle or Scooter Use	13 (11)
High-Risk Behaviour (N = 104 adults)
Any alcohol consumption	83 (80)
Alcohol consumption exceeding safe limits*	13 (16)
Not enough information to quantify	10 (12)
Recreational drug use	3 (3)
New tattoos or piercings	1 (1)
New sexual partner	3 (3)

# Unless otherwise specified

^ There were 29 VFRs who also indicated other reasons for travel as follows: 26 vacation, 1 vacation & pilgrimage, and 3 for other reasons (not otherwise specified). There were 6 non-VFRs who indicated more than one reason for travel as follows: 3 vacation & cruise, 2 vacation & education or business, 1 education or business & volunteering/humanitarianism

§ Visiting friends and/or relatives; If a traveler indicated that they were visiting friends and/or relatives in addition to traveling for other purposes, they were defined as a VFR for this study. There were 26 VFR who indicated they were traveling for vacation purposes, 1 VFR who was traveling for vacation and pilgrimage purposes, and 3 VFR who were traveling for other purposes not specified

⧧ Defined as one month or longer

$ Visited countries categorized based on The World Bank Country and Lending Groups [11]

10 standard drinks a week for women and 15 drinks a week for men (Canada’s Low-Risk Alcohol Drinking Guidelines) [10]

Discrepant trip experiences

Of the 119 travelers who completed post-travel surveys, 109 (92%) reported discrepant experiences with 76 individuals having discrepancies in more than one trip characteristic (Fig 2). Sixty-eight individuals (62%) would have required alternative pretravel counseling due to an increase or different type of risk than anticipated based on the pretravel questionnaire. Changes to planned activities (n = 97) and visited environmental surroundings (n = 66) were the most common discrepancies, and the most common to result in the need for alternative pretravel counseling (54% and 41%, respectively). The majority of these scenarios would not have resulted in different recommendations for pre-travel medication prescriptions. However, three travelers (2.8% of those with discrepant experiences) may have benefited from additional medication recommendations (i.e. malaria prophylaxis while camping or visiting a jungle environment, and altitude sickness preventative medications). Numerous scenarios lacked sufficient detail about actual travel to determine if there would have been a change in pre-travel medication recommendations (n = 21 scenarios, affecting 27.9% of travelers who would have required alternative counseling). In particular, unexpected animal exposure (a new activity exposure) was reported by 17 travelers; however, because questions about the details of the animal exposure were not specifically asked (e.g. a bite from a wild urban dog vs. a visit to an elephant sanctuary), we were unable to determine if pre-travel recommendations would have differed. The regression analysis did not reveal any traveler demographic or trip characteristic that predicted the need for alternative counseling.

Fig 2

Travelers reporting discrepant trips (counts/proportions) (N = 119).

* Participants could report discrepancies in >1 trip characteristic. A total of 76 individuals had discrepancies in more than one trip characteristic.

Among the 104 adult respondents, less than one fifth (n = 17, 16%) reported engaging in high-risk behaviours. Three quarters of these individuals reported excessive consumption of alcohol (n = 13, 76%). There were no significant demographic differences between travelers who reported engaging in any high-risk behaviours and those who did not.

Discussion

To our knowledge, this is the first study to describe discrepant trip experiences among attendees at a family travel medicine clinic. Travelers who completed the post-travel survey were mostly young, healthy adults. A quarter of individuals self-identified as VFRs. The median trip duration was just over 2 weeks, and most often for vacation purposes to a single country. Discrepancies between planned and completed trips were very common and varied across trip characteristics. These differences often altered the health risk to the traveler and would have required alternative pretravel counseling. We did not identify any traveler characteristics that predicted the need for alternative counseling.

International travel has been increasing globally, and in Canada there has been consecutive year-over-year increases since 2012 [12]. VFR travel contributes a substantial amount of tourism worldwide with up to 50% of travel to certain regions by VFR travelers [2, 13]. In the recent definition by the Migration Health Sub-Committee of the International Society of Travel Medicine, ‘a VFR traveler is a traveler whose primary purpose is travel to visit friends or relatives, where there is a gradient of epidemiological risk between home and destination’ [14]. This group is often under-represented in travel-related studies, yet these travelers are at increased risk of travel-related illness [15]. In our study, VFRs made up the minority of participants who completed the post-travel survey. We found that VFR status did not predict either discrepant trip experiences nor discrepancies that would require alternative PC counseling. However, we were unable to assess trip discrepancies for two thirds of the VFR population visiting the clinic during the study period who did not complete the post-travel survey.

Published data examining travel-related health risks to children is limited [16]. Their reason for travel and associated risks usually depend on the adult with whom they are traveling. During the study period, almost half of all travelers who enrolled in the parent study were children aged less than 18 years (n = 136, 46%). Though post-travel surveys were only completed for 15 children, there were 65 children who travelled as part of a family or group unit where another adult returned their post-travel survey. If we assumed that children travelled and stayed in their travel unit and analyzed these additional responses, a total of 56 children (70%) had trip discrepancies in at least one of trip duration, countries visited, accommodations or destinations visited. Twenty-eight of these discrepancies (50%) would have required alternative pretravel counseling. Traveling with a child did not influence the likelihood of discrepant trip experiences or the need for alternative pretravel counseling.

There were limitations to our study. Firstly, patients who choose to obtain a PC are inherently different from those who do not, perhaps reflecting a difference in risk perception and behaviours when traveling. In addition, the cohort who responded to the survey may not have been representative of the complete pre-travel population seen by our clinic, as evidenced by the differences in those who were male, children and identified as VFR (Table 2). Though it is unclear if these demographic differences may have correlated with differences in risk perceptions, it was unlikely this introduced a relevant selection bias given we found the vast majority of travelers had trip experiences that were inconsistent with their planned itineraries and these differences often altered the travel-related health risks to the individual. Secondly, there are limited data to objectively adjudicate the change in risk as a result of a modification in travel itinerary, and the decision algorithm was developed by clinicians based on their clinical experiences and rational judgment. For example, even though World Bank income rankings were used to attribute and compare travel-related risks for different countries, these would not capture differences in durations spent in specific countries or the specific regions that were visited within a given country. Furthermore, the responses from the post-travel survey often lacked sufficient detail to determine if the changes impacted travel within certain endemic illness zones in a given country or if additional vaccinations, prophylaxis or other medications would have been indicated based on the nature of the exposure (i.e. animal exposures). Lastly, we were unable to identify any predictors for the need for alternative pretravel counseling. Many travelers did not complete a post-travel questionnaire and the final size of our cohort limited the robustness of the regression analysis.

Conclusion

We described the travel experiences for a diverse group of travelers who obtained a PC at a family travel medicine clinic located in a busy and multicultural urban setting. The vast majority of travelers reported discrepant trip experiences, with most introducing novel and/or increased risks to their health. Therefore, the advice provided in the original PC may not have been optimal. This study informs practitioners providing pretravel advice to consider broader counselling as discrepancies from planned travel are common.

SickKids family travel clinic pre-travel health consultation and history form.

(PDF)

Click here for additional data file.

Post-travel survey (acute occurrence of risk).

(PDF)

Click here for additional data file.

28 Jun 2021

PONE-D-20-38921

Pretravel plans and discrepant trip experiences among travelers attending a tertiary care centre family travel medicine clinic

PLOS ONE

Dear Dr. Wong,

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- figure 2 can be incoporated into table 2 or table 3 for descriptive purposes.

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Reviewer #1: Yes

Reviewer #2: Yes

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Reviewer #2: Yes

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Reviewer #1: No

Reviewer #2: Yes

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Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

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Reviewer #1: Main comments: The authors have compared pretravel consultation information and and post-trip surveys from 119 participants, finding that 92% reported discrepant trip experiences, two thirds of which would have required alternative pretravel counselling. While there are no major methodological problems, there are a relatively small number of participants, and the impact and potential biases related to losses to follow-up between pre- and post-travel cases need to be better discussed.

Also, the results may be of some interest to readers, but the clinical relevance and details of the changes to the pretravel counselling that would have been warranted based on changes in trip characteristics should be listed so that their importance can be assessed.

Minor issue: Line 102 says that consent was obtained in writing, and then line 115 says that consent was obtained over the phone or in-person. Why the discrepancy?

Reviewer #2: I would recommend the paper for publication.

The paper addresses the subject of travel and pretravel counseling at a very timely moment when more countries are relaxing travel restrictions and individuals are again making International travel plans. The information contained in the sample that was collected during a period of unrestricted travel from October 2014 and November 2015 will be comparable to, and reflective of, the anticipated unrestricted travel environment that is expected in the coming months and years.

The study design is sound and the diversity of the patient population benefits the study. The post-travel follow-up seems adequate and the authors did not lose many patients in follow-up. With a median age of 36.3 years, the study population does skew younger and it would have been advantageous to include an older population, especially people who take cruise vacations.

It is clear that the frequency of changing travel plans necessitates pre-travel counseling, but the study would be improved if there was longer follow-up, especially whether the change in travel plans meant the traveler would have needed a different immunization regime. It would have also been helpful to know if the change in travel plans impacted which endemic illness zone the traveler entered and the effect it had on their required post-travel medications. The time constraint involved with each pre travel visit, will preclude extended counseling required and perhaps the author could discuss this in detail more.

Overall, the study will help identify changing travel patterns among travelers and the health risk associated with it.

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Reviewer #2: No

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21 Sep 2021

Editor’s Comments:

Please review and consider all points raised by reviewers to strengthen the acceptability of this manuscript for publication consideration. In addition, please recommend the following changes:

-Thank you for reviewing our manuscript and providing the opportunity to resubmit a revised version.

Figure 2 can be incorporated into table 2 or table 3 for descriptive purposes.

-We agree that the information in Figure 2 can be concisely incorporated elsewhere. Table 3 (Completed Trip Characteristics) has been updated to reflect this change.

Please address in discussion/limitations section the potential bias of the study sample who completed post-travel and the attendant limitations.

-This is an important limitation to provide further elaboration, and additional details have been included in the discussion section (lines 311-315). We agree that those who completed post-travel surveys likely differed from those who did not, as there were differences in the demographic characteristics between these two groups. The current literature assessing the impact of various traveler characteristics on risk perceptions is limited.

Please address whether the changes would have resulted in different vaccination, chemoprophylaxis, or other empiric medication prescriptions (motion sickness, altitude, anti-diarrheals, lepto prophy, etc.) and the frequency which this would have needed to occur. While it is appreciated that the focus was on pre-travel counseling, it's difficult to entangle this part of the travel medicine practice from provision of vaccines and medications.

-We appreciate the opportunity to provide additional details that may help clinicians who read our manuscript. Regarding over the counter medications (such as those for motions sickness and anti-diarrheals), these would normally have been discussed in the clinical encounter however were not captured in the pre-travel counseling research data. Furthermore, questions in the post-travel survey were not developed to include the details necessary to determine if these additional medication recommendations would have been warranted (e.g. amount of time spent on a boat or the type of boat). Therefore, these medications have not been included in the discussion of specific medication recommendations.

-For the other prescription medications (vaccinations, malaria prophylaxis, altitude-sickness medications) these are now included in the methods section (lines 154-157). The impact on pre-travel medication prescriptions has been detailed in lines 251-263, and Figure 2 has been updated as well. In some scenarios, our assessment was limited by a lack of sufficient detail about actual travel or activities provided in the post-travel surveys, and this limitation has been included in the discussion (lines 322-325). The majority of the time however, the discrepancies would not have resulted in additional medications/vaccinations being prescribed.

Reviewers’ Comments:

Reviewer #1: Main comments: The authors have compared pretravel consultation information and post-trip surveys from 119 participants, finding that 92% reported discrepant trip experiences, two thirds of which would have required alternative pretravel counselling. While there are no major methodological problems, there are a relatively small number of participants, and the impact and potential biases related to losses to follow-up between pre- and post-travel cases need to be better discussed.

-We thank this reviewer for their comments. As suggested in the Editor’s comments, the limitations due to cohort size and loss to follow-up has been further elaborated on in the discussion section (lines 311-315).

Also, the results may be of some interest to readers, but the clinical relevance and details of the changes to the pretravel counselling that would have been warranted based on changes in trip characteristics should be listed so that their importance can be assessed.

-Translating our findings into clinically relevant information has been a focus of this revised manuscript. In addition to the impact on pre-travel medication prescriptions suggested by the Editor’s comments, we also elaborated on the frequency of unexpected animal exposure (details in lines 251-263).

Minor issue: Line 102 says that consent was obtained in writing, and then line 115 says that consent was obtained over the phone or in-person. Why the discrepancy?

-We thank the reviewer for identifying this inconsistency. The clarification has been provided in line 115.

Reviewer #2: I would recommend the paper for publication.

The paper addresses the subject of travel and pretravel counseling at a very timely moment when more countries are relaxing travel restrictions and individuals are again making International travel plans. The information contained in the sample that was collected during a period of unrestricted travel from October 2014 and November 2015 will be comparable to, and reflective of, the anticipated unrestricted travel environment that is expected in the coming months and years.

The study design is sound and the diversity of the patient population benefits the study. The post-travel follow-up seems adequate and the authors did not lose many patients in follow-up. With a median age of 36.3 years, the study population does skew younger and it would have been advantageous to include an older population, especially people who take cruise vacations.

It is clear that the frequency of changing travel plans necessitates pre-travel counseling, but the study would be improved if there was longer follow-up, especially whether the change in travel plans meant the traveler would have needed a different immunization regime. It would have also been helpful to know if the change in travel plans impacted which endemic illness zone the traveler entered and the effect it had on their required post-travel medications. The time constraint involved with each pre travel visit, will preclude extended counseling required and perhaps the author could discuss this in detail more.

Overall, the study will help identify changing travel patterns among travelers and the health risk associated with it

-We thank this reviewer for their comments and are appreciative of the suggestion for future study improvements, including longer study follow-up and discussions around post-travel medication counseling. They have identified important opportunities to elaborate on the discrepant travel plans and the need for alternative immunization regimens as similarly mentioned in the Editor’s comments (details now included in lines 251-263). With regards to the clinically relevant limitation of knowing the change in travel plans and impact on endemic illness zones, this has also been included in the discussion section (lines 322-325).

Submitted filename: Response to Reviewers - Sep 21.doc

Click here for additional data file.

19 Dec 2021

Pretravel plans and discrepant trip experiences among travelers attending a tertiary care centre family travel medicine clinic

PONE-D-20-38921R1

Dear Dr. Wong,

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Mark Simonds Riddle

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PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

25 Jan 2022

PONE-D-20-38921R1

Pretravel plans and discrepant trip experiences among travelers attending a tertiary care centre family travel medicine clinic

Dear Dr. Wong:

I'm 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 let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, 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.

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Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

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on behalf of

Dr. Mark Simonds Riddle

Academic Editor

PLOS ONE