How to meet patients' individual needs for drug information - a scoping review.

PURPOSE: The aim of this study was to 1) describe drug information desired by patients and 2) analyze how such information could be customized to be presented to patients according to their individual information needs.
MATERIALS AND METHODS: We performed a scoping literature search and identified relevant drug information topics by assessing and clustering 1) studies analyzing patients' enquiries to drug information hotlines and services, and 2) qualitative studies evaluating patient drug information needs. For the two most frequently mentioned topics, we further analyzed which components (ie, information domains) the topics contained and examined patients' and health care professionals' (HCPs) views on these components.
RESULTS: Of 27 identified drug information topics in the literature search, patients most frequently requested information on adverse drug reactions (ADRs) and drug-drug interactions (DDIs). Hypothetically, those topics are composed of seven distinct information domains each (eg, ADR and DDI classification by frequency, severity, or onset; information on management strategies, monitoring, and prevention strategies). Patients' and HCPs' appraisal concerning the information content of these domains varies greatly and is even lacking sometimes.
CONCLUSION: Patients particularly request information on ADRs and DDIs. Approaches to customize such information are sparse. The identified information domains of each topic could be used to structure corresponding drug information and to thus facilitate customization to individual information needs.

Introduction

Patient-centered care (PCC) emphasizes patient participation in decision making in order to foster the alliance between health care professionals (HCPs) and patients to share power and responsibility.1 Patients appreciate this approach and several studies indicated positive effects on health outcomes as PCC improves communication, patient involvement, patient-HCP relationship, and treatment adherence.2,3 A prerequisite for shared responsibility is the empowerment of patients based on the provision of understandable information that matches the individual patients’ information needs.3 With regard to drug treatment, patients who have received clear and reasonable treatment recommendations and advice are more likely to adhere to their treatment.4

This may be explained by the fact that basic information on drug treatment is mandatory to fulfill the “Five Rights”,5,6 ie, taking the right drug by the right patient in the right dose at the right time following the right technique to prevent unintentional non-adherence. However, in addition to such evident information needs, patients evaluate the benefits of prescribed drugs (necessity belief) and weigh it against their concerns (concern belief). While a profound “necessity belief” appears to predict adherence, a deeper “concern belief” may lead to non-adherence,7 which, in this context, is often called intentional non-adherence.8 Especially in chronic conditions (eg, hypertension) non-adherence is associated with increased overall health care costs, morbidity, and mortality.4 To efficiently address or prevent a patient’s concern and thereby mitigate at least one reason of non-adherence, the provision of subjectively desired information about treatment and drugs seems a promising approach.3

Which information is relevant to a patient depends on several factors including age, socio-economic status, and comorbidities.9 Depending on the patient’s preferences, both receiving “too much” of unsolicited information and receiving not enough information may have negative effects on patient empowerment, thus amplifying patient concerns. Therefore, it is crucial to customize information toward the individual needs of each patient.9 However, systematic data on which drug information patients want and how it should be edited are sparse.

Unmatched drug information needs are reflected in the growing use of online health information services. Taking Germany as an example, approximately half of its population uses the Internet to get health-related information, and especially services such as medication checks and drug–drug interaction (DDI) checks are frequently accessed.10

To satisfy such unmatched information needs, we aimed to 1) describe drug information desired by patients and 2) analyze how such information could be customized to be presented to patients according to their individual information needs.

Materials and methods

We followed the presumption that drug information can be divided into 1) basic drug information and 2) subjectively desired drug information. Basic drug information refers to drug information that is mandatory for every patient in order to be able to conduct the drug treatment following the concept of the “Five Rights”.5 Subjectively desired drug information, on the other hand, satisfies information customized to individual needs and considers concerns or beliefs with regard to the treatment.

While basic drug information often is straightforward, unambiguous, and therefore easily conveyed in medication schedules,11 no overview exists regarding scope and characteristics of subjective drug information needs.

To describe drug information desired by patients, an exploratory number of articles relating to patient information needs with one of the key words “patient information,” “drug information,” “medication information,” and “medicines information” in title/abstract, English or German language, and with a publishing date between January 2000 and February 2017 were searched. The search purposefully identified potentially relevant studies that were subsequently clustered into two groups: the first group 1) comprised studies analyzing patients’ enquiries to drug information hotlines and services, while the second group 2) comprised qualitative studies evaluating patient drug information needs. From the identified studies in the first group, the total number of drug-related enquiries, the enquiry topics, the provider of the information service, and the timeframe of data enquiry were extracted. The enquiry topics were classified according to those previously defined in the respective study by the authors. From the second group, the study design, population, study site, and raised drug information needs were extracted.

Subsequently, we clustered the different enquiry topics (extracted from studies analyzing patients’ enquiries) and the raised drug information needs (extracted from qualitative studies) as defined in the studies into drug information topics, therewith merging enquiry topics according to their content into broader categories that were consistently defined and applied in both study groups (Table S1 and S2). This allocation was conducted by two clinical pharmacists until concordance was reached (MK and VSW). When this was not possible, a third clinical pharmacist was consulted for clarification (HS). The drug information topics were then counted throughout the different studies and arranged according to frequency in order to identify the most often reported drug information topics and to define the two most frequently mentioned ones (Figure 1).

Figure 1

Flow chart of information extraction from the identified studies and allocation in order to identify the most often reported drug information topics and to define the two most frequently mentioned ones.

Notes: aThe allocation was conducted by MK and VSW. If no agreement was reached, HS was consulted for clarification. Categories that were used for allocation were consistently defined and applied in both study groups (i) and (ii).

Abbreviations: ADR, adverse drug reaction; DDI, drug–drug interaction.

To analyze how such information could be customized in order to be presented to patients, we focused on the two most frequently mentioned information topics and assessed in more detail which components (ie, information domains) the topics contained. Subsequently, we evaluated patients’ and HCPs’ expectations toward the content and presentation of these information domains as described in the literature.

Results

Drug information desired by patients

We identified 12 studies analyzing patient enquiries to drug information hotlines and services.12–23 Most studies analyzed enquiries to drug information hotlines (number of studies [n]=10), while some analyzed enquiries to online information services (n=2). Studies originated from several countries, namely Australia (n=5), the Netherlands (n=2), Germany (n=2), Finland (n=1), United States of America (n=1), and the United Kingdom (n=1). Most of the studies were performed with data originating from the Australian drug information hotline “National Prescribing Service MedicineWise” (NPS MedicineWise) and comprised a plethora of drug-related patient enquiries, most of which were safety-related, such as information on adverse drug reactions (ADRs) and DDIs (Table 1). In the second group, 15 qualitative studies that addressed drug information needs with different methods and in different settings and populations were identified.24–38 Studies were conducted in different countries, namely the Netherlands (n=3), United States of America (n=2), the United Kingdom (n=2), Norway (n=1), China (n=1), Armenia (n=1), Germany (n=1), Singapore (n=1), Australia (n=1), Canada (n=1), and Belgium (n=1). In addition, the studies were conducted in various settings, which were community pharmacies (n=8), residents not recruited in direct health care setting (n=3), hospitals (n=2), practices (n=1), and senior centers (n=1). Various study designs were used in the studies, namely semi-structured interviews (n=7), questionnaires (n=5), focus group discussions (n=2), and presenting commonly asked questions to assess interest in these (n=1). Also, in these studies the majority of the drug information topics raised by the patients were safety-related, most frequently seeking information on ADRs and DDIs (Table 2). Yet, there seemed to be some differences based on study context and setting. Patients in senior centers and hospitals were not interested in information topics like “drugs and driving” and “drug use and alcohol”.27,34,38

Table 1

Studies analyzing enquiry topics to drug information hotlines and services

Study	Study characteristics	Enquiry topicsa as classified in the respective studies and sorted by descending frequency
Crunkhorn et al12	Analysis of (i) enquiries made by or concerning people aged 0–17 years and (ii) enquiries made by or concerning people >18 years to a MCCProvider: NPS Medicine Wise, AustraliaTime: September 2002–June 2010Total number of enquiries:(i) 14,753(ii) 98,117	(i) Made by or concerning people aged 0–17 years:1. Lactation2. Treatment/prophylaxis3. Dose4. Adverse drug reaction5. Interaction6. Vaccination	(ii) Made by or concerning people aged >18 years:1. Adverse drug reaction2. Interaction3. Treatment/prophylaxis4. Mechanism/profile5. Risk/benefit6. Dose
Pijpers et al13	Analysis of enquiries to a MCC related to drug use in pregnancyProvider: NPS Medicine Wise, AustraliaTime: September 2002–June 2010Total number of enquiries: 1,166	Narrative questions and information seeking during pregnancy:1. Preconception: effects on fertility2. First trimester: safety of a specific drug3. Second and third trimesters: preferred/safe treatment of a condition
Benetoli et al14	Analysis of enquiries to a social networking site providing drug informationProvider: Facebook®, information provider: NPSMedicineWise, AustraliaTime: October 2013–October 2014Total number of enquiries: 226	1. Side effects2. Treatment options3. Drug interactions4. Dose/administration5. Mechanism/profile6. Complementary medicines7. Others (eg, cost/vaccination)8. Pediatric9. Pregnancy10. Stability/storage/disposal/formulation
Kloosterboeret al15	Analysis of (i) cough and cold related and (ii) other enquiries to a MCCProvider: NPS Medicine Wise, AustraliaTime: September 2002–June 2010Total number of enquiries(i) 5,503(ii) 117,702	(i) Cough and cold related:1. Interaction2. Other types of concern3. Pregnancy and lactation4. Treatment/prophylaxis5. Adverse drug reaction	(ii) Other enquiries:1. Other types of concern2. Adverse drug reaction3. Interaction4. Treatment/prophylaxis5. Pregnancy and lactation
Van De Belt et al16	Analysis of enquiries asked in an online forum or during (phone/group) consultations by patients of an infertility clinicClinic: Radboud University Medical Center, the NetherlandsTotal number of enquiries: 193	Most frequently asked questionsb1. Medication: use/application2. Schedule of treatment3. Blood loss during treatment4. Medication: side effects5. Quality of oocyte/embryo/semen: lifestyle advices
Huber et al17	Analysis of enquiries to a MCC available exclusively for patientsProvider: Technical University Dresden, GermanyTime: August 2001–January 2007Total number of enquiries: 4,914	1. Adverse drug reaction2. General information about drug3. Information about therapy4. Drug interactions5. Indication/contraindication of drug6. Cost/refund/prescription requirement/drug-related legislation7. Self-medication/dietary supplement/alternative medicine/medical devices8. Application/dosage of drug9. Change of medication10. Mechanism of drug action/pharmacokinetics11. Pregnancy/breastfeeding
Pohjanoksa-Mäntylä et al18	Analysis of enquiries to a community pharmacy-operated MCCProvider: Helsinki University Pharmacy, FinlandTime: 1 week during August 2002Total number of enquiries: 780	1. Costs and reimbursements2. Drug–drug interactions3. Dosage4. Adverse effects5. Indication6. Efficacy7. Drug use and alcohol8. Effective substance9. Mechanism of action10. Taking medicine correctly11. Contraindication12. Storage13. Breaking up medication14. Safety of drugs during pregnancy15. Formulation16. Drugs and driving17. Dependency
Maywald et al19	Analysis of enquiries to a MCC available exclusively for patientsProvider: Technical University Dresden, GermanyTime: September 2001–September 2003Total number of enquiries: 2,049	1. ADR (adverse drug reaction)/drug interaction2. Information about drugs or therapies3. Self-medication4. Indications/contraindications5. Dosage and administration6. Pharmacokinetics7. Refund and legalities8. Miscellaneous
Assemi et al20	Analysis of enquiries submitted to an online “Ask Your Pharmacist” drug information serviceProvider: University of California at San Francisco, USATime: 1999–2000Total number of enquiries: 1,087	1. Indications, efficacy, mechanism of action2. Adverse effects3. Other (non-health-related)4. Other health-related questions5. Drug identification6. Drug–drug or drug–food interactions7. Dosing issues8. Pharmacokinetics (eg, time to onset of effects)9. Drug stability
Weersink et al21	Analysis of enquiries related to (i) antipsychotic drugs and (ii) rest of enquiries to a MCCProvider: NPS Medicine Wise, AustraliaTime: September 2002–June 2010Total number of enquiries:(i) 6,295(ii) 119,624	(i) Antipsychotic drugs:1. Safety2. Efficacy3. Judicious use4. Other	(ii) Rest of enquiries:1. Safety2. Efficacy3. Judicious use4. Other
Marvin et al22	Analysis of enquiries made by citizens to a hospital pharmacy drug information lineProvider: Chelsea and Westminster Hospital London, United KingdomTime: 6 months in 2008Total number of enquiries: 500	1. Interaction2. Directions3. Side effect4. Supply5. Error6. Safety in pregnancy7. What is it for8. Storage/expiry9. Allergy10. Unknown
Bouvy et al23	Analysis of enquiries to (i) a toll-free drug information hotline and (ii) enquiries to a free drug information websiteProvider: Royal Dutch Association for the advancement of Pharmacy, the Netherlands/Private initiative website by volunteer pharmacists, the NetherlandsTime: February 2000Total numbers of enquiries:(i) hotline: 305(ii) website: 183	(i) Hotline:1. Adverse reactions/safety2. General information on a specified drug3. Interactions and alternative drugs and effectivity mechanism of action4. Dependency and stopping5. Therapeutic advice/comparison of products/changing of medications6. Dosage and time schedule and general information on diseases and groups of drugs7. Availability of the product/reimbursement8. Second opinion9. Pregnancy10. Lactation11. Information for school and use outside licensed indication	(ii) Website:1. General information on diseases and groups of drugs2. Therapeutic advice/comparison of products/changing of medications3. Adverse reactions/safety4. Availability of the product/reimbursement5. Alternative drugs6. General information on a specified drug7. Information for school8. Effectivity mechanism of action9. Dosage and time schedule10. Use outside licensed indication11. Pregnancy12. Dependency and stopping13. Interactions14. Second opinion

Notes:

Enquiry topics of studies, besides those by Pijper et al13 are listed according to their frequency in each individual study. In some studies, one call could contain more than one enquiry topic. Names of enquiry topics were extracted verbatim from the respective studies;

In total, there were 24 different themes according to which the patients’ questions were categorized.

Abbreviations: MCC, medicines call center; NPS MedicineWise, National Prescribing Service MedicineWise.

Table 2

Qualitative studies evaluating patient drug information needs

Study	Study characteristics	Raised drug information needsa
Sage et al24	Presenting parents of children with “attention deficit/hyperactivity disorder” a list of commonly asked questions to assess interest in thesePopulation: 70 parents, mostly femaleStudy site: Private pediatric practices, United States	Questions of highest interest by parents (analogously extracted):• Long-term effects• Treatment• Side effects• Interaction• Dosage• Dosing schedule• Indication and side effects• Availability and drug name• Drug and driving
Abraham et al25	Semi-structured interviews with thematic analysis to assess parents’ perspectives on pediatric medicationPopulation: 19 parents, mostly femaleStudy site: Community pharmacies, United States	Essential drug information requested by parents:• Drug interactions• Side effects
Twigg et al26	Questionnaire to measure medication information satisfaction of patients who (i) received an advanced counseling service and (ii) those who did notPopulation: Patients with more than one regular medicine, 232 assessed questionnairesStudy site: Community pharmacies, United Kingdom	Score for the potential problems (SIMS score 2), unsatisfied with information on:(i) Patients who received service• Whether the medication will affect your sex life• Whether the medicine interferes with other medicines• What are the risks of you getting side effects• What you should do if you experience unwanted side effects• Whether the medicine has any unwanted effects• Whether the medication will make you feel drowsy• Whether you can drink alcohol while taking this medicine• What you should do if you miss a dose	Score for the potential problems (SIMS score 2), unsatisfied with information on:(ii) Patients who received no service• What are the risks of you getting side effects• Whether the medicine has any unwanted effects• Whether the medication will affect your sex life• Whether the medicine interferes with other medicines• What you should do if you experience unwanted side effects• What you should do if you miss a dose• Whether the medication will make you feel drowsy• Whether you can drink alcohol while taking this medicine
Mamen et al27	Structured questionnaire to assess patients’ need for drug informationPopulation: 162 elderly patients who used at least one prescription medicineStudy site: Senior centers, Norway	Information patients would like to have:• General information/everything• Side effects• How the drug works/what it does• Interactions• Indication of drug• Is it working/is it necessary• Duration of treatment• Other questions
Yi et al28	Questionnaires for patients and physicians to identify gaps regarding medication education, content, and deliveryPopulation: 108 ambulatory care patients, 116 hospital clinics physiciansStudy site: Outpatient pharmacy and hospital clinics, China	Topics with largest difference between information desired by patients and received information:• What to do if adverse reaction experienced• Drug–food interactions• Drug–drug interactions• Adverse reactions• Onset of action• Duration of therapy• Medication storage
Kazaryan and Sevikyan29	Interview to identify patients’ needs of drug informationPopulation: 1,059 people who visited community pharmaciesStudy site: Community pharmacies, Armenia	Information requested by patients:• Indication• Dosage and method of administration• Contraindications• Adverse reactions• Simultaneous use of multiple medicines• Information about medicine’s price
Mahler et al30	Standardized questionnaires consisting of SIMS-D and MARS-D to assess the extent to which patients are satisfied with drug informationPopulation: 834 chronically ill patientsStudy site: Heidelberg, Germany	Score for the potential problems (SIMS score 2), unsatisfied with information on:b• What are the risks of you getting side effects• Whether the medication will affect your sex life• Whether the medicine has any unwanted effects• What you should do if you experience unwanted side effects• Whether the medicine interferes with other medicines• Whether the medication will make you feel drowsy• What you should do if you miss a dose• Whether you can drink alcohol while taking this medicine
Ho et al31	Questionnaire to identify patients’ needs of drug informationPopulation: 201 patients in an outpatient pharmacyStudy site: Outpatient pharmacy of a university hospital, Singapore	Information wanted:• Adverse effects• Dosing• Indication• Interactions (drug–drug, herb–drug)• Mechanism of action• Use of devices• Pregnancy or breastfeeding
Newby et al32	Telephone survey to investigate information seeking behavior and questions asked about drugs by drug users with (i) satisfied and (ii) unmet needs of drug informationPopulation: 61 residents who completed follow-up interviewsStudy site: Residents in New South Wales, Australia	Questions asked about drugs:(i) Drug users with satisfied needs• Adverse effects• How well medicine worked for a particular condition• Advice on the best treatment for a particular condition• Other• Reason for taking the medicine• General inquiry about a medicine• How to use the medicine• Interactions• Pregnancy and lactation	Questions asked about drugs:(ii) Drug users with unmet needs• Adverse effects• How well medicine worked for a particular condition• Other• Advice on the best treatment for a particular condition• General inquiry about a medicine• Reason for taking the medicine• How to use the medicine• Pregnancy and lactation• Interactions
van Geffen et al33	Semi-structured telephone interviews to identify patients’ information needs when starting with SSRI treatmentPopulation: 41 patients with first prescription of a SSRIStudy site: Community pharmacies, the Netherlands	Information wanted at start of treatment:• Delayed onset of action• Adverse effects• Dependency• Reasons for use• Consequences of long-term use• Interactions• Duration of treatment and discontinuation
Zwaenepoel et al34	Standardized interviews to explore information preferences of psychiatrics inpatientsPopulation: 279 psychiatric inpatientsStudy site: Psychiatric hospitals, Belgium	Information wanted:• Side effects• How does the drug work?• What is drug taken for?• No further information• Addictive?• Interactions?• Harmful?
Lamberts et al35	Semi-structured telephone interviews and patient focus group discussions to obtain insights into information needs of patients who have recently started treatment with oral antidiabeticsPopulation: 42 patients with first prescription of an oral antidiabetic, 11 further participating in 2 focus groupsStudy site: Community pharmacies, the Netherlands	Information wanted according to patients:• What your medicine is for• What you should do if you forget a dose• Whether the medicine interferes with other medicines• How to use your medicine• How long you will need to be on your medicine• How long it will take to act• Whether the medicine has any unwanted effects• How it works• What are the risks of stopping the medicine• What are the risks of you getting side effects
Nair et al36	Focus groups to explore what patients want to know about their medication and how HCPs respond to these information needsPopulation: 88 patients who had taken at last one medication, 27 physicians, and 35 pharmacists in 19 focus groupsStudy sites: British Columbia, Nova Scotia, Ontario, Canada	Information topics discussed:• Side effects and risk information• Range of treatment options• How long to take medication• Cost of medication• Is this medication right for me?
Raynor et al37	Focus groups to examine the experiences with drug information of people with a chronic illnessPopulation: 23 patients with asthma participating in 4 focus groupsStudy site: Community pharmacies, United Kingdom	Information need areas identified:• Name and purpose of treatment• When and how to take it; how long to take• Side effects and what to do about them• Problems with other drugs• How to tell if it is not working
Borgsteede et al38	Semi-structured interviews to explore patients’ needs of information about their medication at hospital dischargePopulation: 31 patients being discharged from the hospitalStudy site: General teaching hospital, the Netherlands	Information aspects important for patients:• Basic information (eg, drug name, indication, use)• Information about side effects• Information about alternatives• What to do when medication problems are encountered

Notes:

In some studies, more than one information topic could be given by study participants;

The study used a German version of the SIMS; wording of the topics raised is according to the respective English version.

Abbreviations: HCP, health care professional; MARS, Medication Adherence Reporting Scale; SIMS, Satisfaction with Information about Medicines Scale; SSRI, selective serotonin reuptake inhibitors.

Some information topics like “cost, refund, and prescription requirement” and “stability, storage, and disposal” were predominantly mentioned in ambulatory settings (ie, pharmacies and residents).28,29,36 Such topics were also more often mentioned in studies analyzing patient enquiries to drug information hotlines and services. The majority of raised drug information topics were largely identical in the examined studies regardless of whether semi-structured interviews or questionnaires were used. Focus groups that were held between patients and researchers,36 and patients, physicians, and pharmacists,37 also freely discussed predominantly safety-related drug information topics in addition to information topics that can be considered to follow the principle of the “Five Rights,”5 such as “dose and administration,” “indication,” and “duration of treatment.” Arrangement of the allocated drug information topics according to frequency yielded ADRs and DDIs as the drug information topics most often sought by the patients regardless of country, setting, and study design. Other frequently requested drug information topics were dose and administration (ie, how and in which strength to take the drug), indication of a drug, and treatment options (ie, whether alternative drugs can be used to treat the condition). Selected topics of lower interest were information on vaccination, off-label use, drug formulation, and allergy (Figure 2).

Figure 2

Arrangement of the allocated drug information topics according to frequency of mentioning in assessed 1) studies on drug information hotlines (solid bars) and 2) qualitative studies (open bars).

Notes: aThe frequencies (absolute number) with which a respective drug information topic was mentioned in the assessed studies were summed up. *Drug information topics that can be considered to be mandatory to conduct the drug treatment (“Five Rights”).

Abbreviations: ADR, adverse drug reaction; DDI, drug–drug interaction.

Customization of drug information

Both ADR and DDI information may be composed of seven different information domains each (Table 3): ADR information could be customized according to the frequency, severity, onset of ADRs (eg, start of therapy vs long-term effects), duration of ADRs (eg, long-term vs short-term), and management strategies including limitations of self-management (ie, how to minimize ADRs and when to consult a physician). Moreover, additional information could be given on appropriate monitoring and prevention strategies (eg, tools to cope with ADRs).

Table 3

The two most frequently mentioned drug information topics and their information domains

Drug information topic	Information domains	Amount of information desired by patients and implications in the literature	Health care professionals’ perceptions and worries
ADRs	Classification by• Frequency according to SmPC using qualitative EU guideline descriptions (ie, very common, common, uncommon, rare, very rare)46	• Some patients do not want any information33,38–41• Some patients want a full disclosure of all possible ADRs36,38–41• Some patients want specific ADR information categorized by frequency with common ADRs being of greater interest39,42–45• Patients do not want physicians to tailor ADR information for them39Implications in the literature• Using the qualitative EU guideline descriptions for frequency leads to massive overestimation of perceived risk46• Meta-analysis: risk of ADRs should be quantified numerically47• Higher desire for ADR information by patients with previous experiences of ADRs34,39,48	• Physicians and pharmacists question the amount of ADR information as a cause of non-adherence36,41,49–53 and know patients who do not want any information50• Physicians and pharmacists differ on who should discuss ADRs with patients because each profession considers itself more capable or the other profession responsible for doing so33,41,49Extent of ADR information during physician consultations• ADR information is often not part of consultations54• Physicians are more likely to inform on ADRs that occur frequently52,53
	Classification by• Severity (ie, serious or non-serious ADRs)	• Some patients do not want any information33,38–41• Some patients want a full disclosure of all possible ADRs36,38–41• Some patients want specific ADR information categorized by severity with dangerous ADRs being of greater interest39,42–45• Patients do not want physicians to tailor ADR information for them39Implications in the literature• Using the qualitative EU guideline descriptions for frequency leads to massive overestimation of perceived risk46• Meta-analysis: risk of ADRs should be quantified numerically47• Higher desire for ADR information by patients with previous experiences of ADRs34,39,48	• Physicians and pharmacists question the amount of ADR information as a cause of non-adherence36,41,49–53 and know patients who do not want any information50• Physicians and pharmacists differ on who should discuss ADRs with patients because each profession considers itself more capable or the other profession responsible for doing so33,41,49Extent of ADR information during physician consultations• ADR information is often not part of consultations54• Severity does not seem to influence likelihood that physicians inform on ADRs52,53
	Classification by• Onset of ADRs (eg, start of therapy vs long-term effects)	• Patients want information on ADRs occurring both early on and during long-term treatment33,37,55	• No data available
	Classification by• Duration of ADRs (eg, long-term vs short-term)	• No data available	• No data available
	Classification by• Management strategies including limitations of self-management (ie, how to minimize ADRs and when to consult a physician)	• Patients want information on how to reduce ADRs33	• No data available
	Additional information on• Monitoring	• Patients want information on how to reduce ADRs33	• No data available
	Additional information on• Prevention strategies	• Patients want information on how to avoid ADRs33	• No data available
DDIs	Empowerment to identify interactions• Identification of interaction partners	• Some patients believe that drugs counteract with each other when taken together, while some trust their prescriber that no DDIs will occur55• Patients request information on interactions between prescription drugs and OTC medications (11.4%)56• Patients request information on interactions between drugs and food (6.8%)56• Patients are interested in identification of interaction partners because 62% of the female participants wanted to learn more about DDIs between hormonal contraceptives and antiepileptic drugs57Implications in the literature• Focus should be put on interactions with OTC drugs and food58,59• Patients fail to transfer knowledge on DDI management into practice60	• No data available
	Classification by• Frequency (ie, the frequency with which a DDI may occur)	• Patients request information on frequency (2.3%) and prevalence of DDIs (2.3%)56	• No data available
	Classification by• Severity (ie, a serious or non-serious DDI effect)	• Patients request information on seriousness (19.3%) and effects of DDIs (5.7%)56	• No data available
	Classification by• Onset of DDIs (ie, most likely timing when a DDI occurs)	• No data available	• No data available
	Additional information on• Management strategies including limitations of self-management (ie, how to minimize DDIs and when to consult a physician)	• Patients request information on management of DDIs (eg, influence of timing and dose) (2.3%)56	• No data available
	Additional information on• Monitoring	• Patients request information on signs of DDIs (3.4%)56	• No data available
	Additional information on• Prevention strategies	• Patients request information on how to prevent DDIs (eg, influence of timing and dose) (2.3%)56	• No data available

Abbreviations: ADR, adverse drug reaction; DDI, drug–drug interaction; EU, European Union; OTC, over-the-counter; SmPC, Summary of Product Characteristics.

For DDIs, customization could refer to the identification of DDIs, frequency, severity, or onset of DDIs. Furthermore, additional information on management strategies including limitations of self-management, monitoring, and prevention strategies (eg, different timing, lower dosages, and alternative medicines) could be given.

The subsequent literature search illustrated some of these domains with patients’ needs and HCP perceptions regarding extent of information wanted because especially classification of ADRs by frequency and severity was often mentioned in the assessed literature. However, the majority of the domains were never extensively assessed in patients or HCPs. Hence, knowledge of whether and to which extent patients require the diverse elements of information and to what extent HCPs support them is limited.

Discussion

Patients request largely differing information on their drugs beyond the basic information of the “Five Rights” provided in medication schedules. Thereby, information needs verbal-ized in qualitative studies are reflected in actual enquiries to information hotlines and services. Undoubtedly, safety-related information on ADRs and DDIs is most often sought.30,37

In comparison to other drug information topics such as appropriate storage of drugs or indication of a drug, relevant information on ADRs and DDIs is broader and less explicit. Hence, if patients request information on ADRs, it typically remains unclear what they actually want to know. For instance, do patients want to learn only about the most frequent ADRs, or the most severe ones, or those they can independently monitor and manage? Nevertheless, such safety-related information might particularly interfere with patient concerns about their drug treatment and may hence also influence their adherence to drug treatment because lacking information might promote a deeper “concern belief” and thus non-adherence.7,8 Owing to the high diversity of ADR and DDI information, it is difficult to satisfy individual needs, identify information deficits, and provide missing details while avoiding to transfer information that is not sought or irrelevant in the current patient situation.

For both ADRs and DDIs, we identified seven distinct information domains that would allow for customizing information. Such customization would then enable HCPs to individually provide patients with the respective drug information of personal interest. Only little is published on patient attitudes toward these information domains and even fewer evidence exists on how patient needs could be assessed to identify unmet information needs.

For instance, there are patients who decline to receive additional information and treatment willingness of some patients already diminishes when the mere presence of possible ADRs is mentioned, regardless of their likelihood of occurrence.61 Often, this fear of potential non-adherence is put forward by HCPs who are reluctant to offer what they deem too much additional information. However, this fear is not reflected in literature.62,63

At the other extreme, some patients want a full disclosure of all possible ADRs. Indeed, patients often seem to follow a safety-conscious strategy and opt for a maximum of information without a real understanding of risk and likelihood.39,46 Furthermore, patients seem to be particularly interested in risks considered most threatening for their own well-being regardless of their likelihood of occurrence.44

The majority of patients probably is situated in between these two extremes, and while customization of information to satisfy individual needs is acknowledged,58 explicit endeavors remain scarce. Often, patients are left with patient information leaflets that follow a “one-size-fits-all” approach and the vast number of ADRs mentioned often causes undesirable emotional reactions (eg, fear) that might promote non-adherence.42 With regard to DDIs, some patients believe that a lot of drugs should not be combined because their efficacy could be altered, whereas other patients believe that co-prescribed medicines are unlikely to interact at all.55 Considering self-medication in particular, there is a need to inform patients and raise awareness about possible DDIs between prescribed drugs and those used in self-medication.

While extensive research has been undertaken to assess professional DDI checkers regarding their content, design, and use in a professional setting, there is very limited information on performance of DDI checkers informing patients and laypersons.64 Many available DDI checkers lack DDI severity information, contain only limited patient-oriented risk communication, and have only limited patient readability.64 Especially, lengthy and complex information on possible DDIs is not well understood.65 Future research is therefore necessary to facilitate 1) customization of ADR information and 2) customization of DDI information with advanced drug information management in order to enable customization possibilities. Besides enabling customization possibilities of drug information, a particular emphasis must be put on making this information easily accessible for future users (eg, patients). Therefore, in a subsequent step, low-threshold dissemination channels must be assessed and validated with patients.

A first step would be to develop, validate, and release a database that contains available drug information in commonly understood language and register that is structured according to relevant identified information domains (Table 3). Such a database would allow selecting only information domains important for the individual patient and would thus individualize information transfer. A second prerequisite would be a tool to assess and identify individual drug information needs and select information domains for which a patient wants additional information. There are already tools available to assess whether patients desire more or less information in general and about their drugs in particular, such as the “Extent of Information Desired” scale,9 and tools that help measuring overall satisfaction with drug information, such as the “Satisfaction with Information about Medicines Scale”.26,30 However, a tool to determine specific information domains on ADRs and DDIs to allow patients to select the amount and content of additional drug information is lacking. To recognize and identify boundaries and implications of customized drug information, it will be crucial on the one hand to identify patient populations benefiting from such a form of information. On the other hand, it will be equally important to find those patients who do not need additional information, and particularly those who are not served by such an approach while being in need of additional information – to this end, it may also be necessary to include further patient characteristics that influence information needs, predominantly the patient’s health literacy.66 Looking at the literature, high desires for information were expressed for instance by patients with diabetes diagnosis, whereas patients with cardiovascular and respiratory diseases expressed lower desires for drug information.9 Additional factors like diseases and comorbidities may therefore also influence individual information needs.9,34 How and in which way such influence takes place should consequently also be assessed.

Limitations

The present work has several limitations. First, we conducted a narrative instead of a systematic review and only assessed a single (albeit large) database (PubMed). However, our aim was to identify the most relevant drug information topics and highlight how such information can be customized. With a narrative approach we were able to include a broad spectrum of articles and therefore widely assess drug information needs. The topics extracted from PubMed articles showed strong consistency and little deviation of topics mentioned, therewith suggesting an already sufficient approach. Furthermore, while not applying the full range of the “Preferred Reporting Items for Systematic Reviews and Meta-Analyses” (PRISMA) statement, we still applied various checklist items in our review process whenever possible (eg, eligibility criteria, information sources, data collection progress, synthesis of results, study characteristics, summary of evidence, limitations, conclusions, and funding).67

Second, our approach to assess unsatisfied drug information needs by analyzing enquiries to drug information hotlines and services might be biased by the fact that actively calling a hotline requires some basic interest in drug-related topics and ambition to self-reliantly acquire information; therefore, more “empowered” and proactive patients may be selected by this approach and less empowered patients might be missed. Nevertheless, the second assessment of unmatched information needs including a variety of qualitative studies yielded similar results, supporting the conclusion that these findings indeed reflect the drug information needs of a broad population of patients.

Conclusion

Patients particularly request safety-related drug information that exceeds the typical scope of medication schedules. While it is well known that extent and content of the favored information can vary, evidence on how to assess information needs and correspondingly customize information is sparse. This review suggests that for both ADRs and DDIs, rather diverse but only limited information domains are needed and that individual patients largely differ with respect to their information needs.