Accuracy in patient-reported adverse drug reactions and their recognition: a mixed-methods study

BACKGROUND

The causality assessment tool can be utilized to assist patients in identifying adverse drug reactions (ADRs).

AIM

To evaluate the accuracy of the causality assessment tool for patients identifying ADRs compared to assessments made by pharmacists, and to explore how patients recall and recognize symptoms as ADRs.

METHOD

Mixed methods study consisting of self-administered questionnaires (phase 1) and semi-structured, face-to-face interviews (phase 2) with patients who had experienced ADRs in the past year at a tertiary care hospital in Thailand.

RESULTS

Out of 769 questionnaires, 716 were returned and 622 of these were both valid and had at least one ADR (86.8%). Classification of patient-reported symptoms using the causality assessment tool found 12 (1.9%) highly-probable ADRs, 399 (64.1%) probable ADRs, 207 (33.3%) possible ADRs, and 4 (0.6%) that were not classified as ADRs. There was fair agreement between patient-assessed and pharmacist-assessed causality classifications using the Naranjo algorithm (K = 0.268) and the World Health Organization Uppsala Monitoring Centre (WHO-UMC) criteria (K = 0.373). The timing relationship between the occurrence of symptoms and administration of a suspected drug was the most frequently mentioned reason that patients gave for recalling and recognizing suspected ADRs.

CONCLUSION

Promoting the causality assessment tool for use by patients in collaboration with healthcare professionals is likely to enhance patients' ability to correctly identify ADRs and ultimately contribute to increased medication safety.

Comparing patient reported and medical record data of adverse drug reactions to anti-seizure drugs

BACKGROUND

Anti-seizure drugs (ASDs) can potentially cause serious adverse drug reactions (ADRs). Patient self-reporting can increase the rate of ADR detection, but studies examining patient self-reporting of ADRs caused by ASDs are lacking.

AIM

To determine the characteristics of ADRs reported by patients receiving ASDs, assess laboratory data and medical record confirmation of patient-reported ADRs, and explore factors associated with laboratory data and medical record confirmation.

METHOD

A self-reporting questionnaire was distributed to patients prescribed ASDs at outpatient clinics. Patients assessed the causality of suspected ADRs using Causality Assessment Tool. Naranjo's algorithm was used by researchers for causality assessment. Medical records were used to gather information on ADR symptoms, ASD medication, and abnormal laboratory data.

RESULTS

From 478 distributed questionnaires, 93.1% completed the questionnaire and 67.4% of respondents reported at least one ADR. The most common ADRs were drowsiness (50.7%), dizziness (9.7%), and ataxia (4.3%). For causality, suspected ADRs were classified as possible in 52.3% of cases and probable in 46.3% of cases by patients, and possible in 64.7% of cases and probable in 25.7% of cases by researchers. Only 12.7% of patients had laboratory data and/or medical record confirmation of suspected ADRs. The psychiatry clinic was less likely to confirm suspected ADRs compared to the epilepsy clinic (OR = 0.412, p = 0.022).

CONCLUSION

Confirmation of patient-reported ADRs with either laboratory data or medical records was uncommon. Recording patient-reported ADRs in patients' medical history and monitoring laboratory tests related to patient-reported symptoms should be promoted to increase the safety of ASD treatment.

A nationwide survey of methods and barriers to adverse drug reaction monitoring and reporting among hospital pharmacists in Thailand

OBJECTIVES

To explore the methods of adverse drug reaction identification and monitoring used by hospital pharmacists in all regions of Thailand, to explore barriers to and pharmacists' attitudes towards adverse drug reaction monitoring and reporting, and to assess the factors related to these aspects.

METHODS

Pharmacists in 480 hospitals in Thailand were selected by stratified sampling. Self-administered questionnaires were sent by post and pharmacists returned completed questionnaires via QR code.

KEY FINDINGS

In total, pharmacists at 286 hospitals returned the questionnaire (response rate = 59.6%). The most common adverse drug reaction (ADR) monitoring methods were the spontaneous reporting system (SRS), which was used by 100% of respondents, followed by high alert drug lists (73.1%) and routine adverse drug reaction monitoring (64.0%). The most frequently used methods of adverse drug reaction prevention were providing drug allergy card and recording allergy history in database. The major barrier to adverse drug reaction monitoring and reporting among respondents was uncertainty about whether the suspected drug caused the reaction (49.3%). Pharmacists had a good attitude towards adverse drug reaction monitoring and reporting (60.5%). Longer work experience (≥10 years) was negatively related with good attitudes towards adverse drug reaction monitoring and reporting (OR = 0.535, P = 0.040), whereas higher education level was positively related (OR = 2.201, P = 0.025).

CONCLUSIONS

Spontaneous reporting system is the main method used for adverse drug reaction monitoring and reporting among hospital pharmacists in Thailand. Pharmacists had good attitudes towards adverse drug reaction monitoring and reporting, however, barriers remain.

Severity and Management of Adverse Drug Reactions Reported by Patients and Healthcare Professionals: A Cross-Sectional Survey

Adverse drug reaction (ADR) severity levels are mainly rated by healthcare professionals (HCPs), but patient ratings are limited. This study aimed to compare patient-rated and pharmacist-rated ADR severity levels and determined methods employed for ADR management and prevention by patients and HCPs. A cross-sectional survey was conducted in outpatients visiting two hospitals. Patients were asked about ADR experiences using a self-administered questionnaire, and additional information was retrieved from the medical records. In total, 617 out of 5594 patients had experienced ADRs (11.0%), but 419 patients were valid (68.0%). Patients commonly reported that their ADR severity level was moderate (39.4%), whereas pharmacists rated the ADRs as mild (52.5%). There was little agreement between patient-rated and pharmacist-rated ADR severity levels (κ = 0.144; p < 0.001). The major method of ADR management by physicians was drug withdrawal (84.7%), while for patients, it was physician consultation (67.5%). The main methods for ADR prevention by patients and HCPs were carrying an allergy card (37.2%) and recording drug allergy history (51.1%), respectively. A higher level of ADR bothersomeness was associated with higher ADR severity levels (p < 0.001). Patients and HCPs rated ADR severity and used ADR management and prevention methods differently. However, patient rating of ADR severity is a potential signal for severe ADR detection of HCPs.

Evaluation of Medicine Information Leaflets for Omeprazole, Safety Knowledge, and Perceptions of Taking the Medication in Thailand

PURPOSE

This study aimed to compare package inserts and patient information leaflets for omeprazole in terms of the quality of and satisfaction with the written medicine information, medication safety knowledge, and perceived benefits and risks.

PATIENTS AND METHODS

A cross-sectional, comparative study was conducted at a university hospital in Thailand. Outpatients visiting the pharmacy departments prescribed omeprazole were randomly selected to receive either a package insert or a patient information leaflet. Medication safety knowledge was measured using a set of eight questions. The quality of the written medicine information was measured by the Consumer Information Rating Form. Perceived benefits and risks of the medication were rated using a visual analog scale. Linear regression was used to determine factors associated with perceived benefits and risks.

RESULTS

Of the 645 patients, 293 agreed to answer the questionnaire. 157 and 136 patients were given patient information leaflets and package inserts, respectively. Most respondents were female (65.6%), over half had a degree (56.2%). Patients reading the patient information leaflets had slightly higher overall safety knowledge scores than those reading the package inserts (5.88 ± 2.25 vs 5.25 ± 1.84, p=0.01). Using the Consumer Information Rating Form, the patient information leaflets were given significantly higher scores compared to the package inserts for comprehensibility (19.34±3.92 vs 17.32±3.52, p<0.001) and design quality (29.25 ± 5.00 vs 23.81 ± 5.16, p<0.001). After reading the leaflets, patients receiving the patient information leaflets had significantly higher satisfaction with the information provided (p=0.003). In contrast, those receiving the package inserts rated the risks of omeprazole higher (p=0.007).

CONCLUSION

Demonstrable differences were found from the patient perspective between a package insert and a patient information leaflet for the same medicine, mostly in favour of patient information leaflets. Medicine safety knowledge after reading PI and PIL was similar. However, receiving package inserts provided higher perceived risks from taking the medicine.

Evaluation of patient comprehension and quality of consumer medicine information

Background

Consumer medicine information (CMI) is voluntarily produced by pharmaceutical manufacturers in Thailand, but quality assessment of Thai-CMI is not routinely performed.

Objective

This study aimed to evaluate the content and design quality of CMI available in Thailand and assess patient understanding of the medicine information provided.

Methods

A cross-sectional study that consisted of two phases. Phase 1 was expert assessment of CMI using 15-item content checklists. Phase 2 was patient assessment of CMI by user-testing and the Consumer Information Rating Form. Participants (n=130) were outpatients aged 18 years or older with an educational level of less than grade 12. Self-administered questionnaires were distributed to patients at two university-affiliated hospitals in Thailand.

Results

A total of 60 CMI produced by 13 Thai pharmaceutical manufacturers were included in the study. Most of the CMI contained essential information about the medicines, but lacked information about serious adverse effects, maximum dose, warnings, and use in specific patient groups. Of 13 CMI selected for user-testing, none met the passing criteria with only 40.8% - 70.0% of answers found in the correct position and answered correctly. The mean values of patients' rating the CMI were between 2.5 (SD=0.8) and 3.7 (SD=0.5) for utility on a 4-point scale, and 2.3 (SD=0.7) to 4.0 (SD=0.8) for comprehensibility and 2.0 (SD=1.2) to 4.9 (SD=0.3) for design quality on a 5-point scale. Eight CMI were rated as poor (less than 3.0) for font size.

Conclusion

More safety information about medications should be included in Thai CMI and the design quality must be improved. CMI needs to be evaluated before distribution to consumers.

Exploring Healthcare Professionals' Practices and Attitudes towards Monitoring and Reporting of Severe Adverse Drug Reactions

Healthcare professionals (HCPs) play a key role in the monitoring of severe adverse drug reactions (ADRs). The present study aims to explore practices and barriers of HCPs in severe ADR monitoring and reporting, to evaluate their attitudes towards the monitoring and to assess the related factors. Self-administered questionnaires produced in hard copy and Google form were sent to 510 HCPs by stratified random sampling. Of the 350 HCPs that responded (68.6%), 44.9% had ever monitored ADRs. The most common practices were the observation of abnormal symptoms for ADR identification (88.5%), discontinuation of the suspected drug for ADR management (88.5%) and advice on recurrent drug allergy for ADR prevention (88.5%). Most HCPs (93.0%) obtained further patient history to identify severe ADRs. The uncertainty of the causal relationship was a major barrier to ADR reporting (60.0%). Pharmacists were more involved with practices in ADR monitoring and reporting (OR 20.405; p < 0.001), whereas longer work experience (>20 years) was negatively related to the practices (OR 0.271; p = 0.024). Over one-third (37.6%) of HCPs had a positive attitude towards severe ADR monitoring. In conclusion, the practices in severe ADR monitoring varied among different professions. However, the barriers to the reporting of ADRs still exist; hence, improving knowledge and cooperation among HCPs should be promoted.

Thai Patients' Drug Safety Knowledge and Perceptions Relating to Different Forms of Written Medicine Information: A Comparative Study

PURPOSE

The aim of the study was to evaluate the medication safety knowledge, quality of the written medicine information (WMI), and perceptions of taking the medicines in patients receiving package inserts (PIs) in comparison with patient information leaflets (PILs).

METHODS

A cross-sectional, comparative study was conducted from December 2020 to May 2021 at two university hospitals in Thailand. Outpatients who visited the pharmacy departments and were prescribed one of the three medicines: atorvastatin, celecoxib, or metformin were randomly selected by a permuted block randomization. The medication safety knowledge was measured using a set of validated and closed questions. The quality of the WMI was measured by the Consumer Information Rating Form (CIRF). Satisfaction with information and perceptions of the benefits and risks of medications were rated by the participants using a visual analog scale (0 to 10).

RESULTS

Of the 1150 invited patients, 750 completed the questionnaires (65.2%). A higher proportion of respondents with high level of medication safety knowledge was found in those reading the PILs than the PIs (44.5% and 20.8%, respectively). The type of leaflet received was a significant predictor of the high knowledge level (p < 0.001). The mean CIRF scores were significantly higher among those reading the PILs than the PIs (p < 0.001). Patients reading the PILs were also more satisfied with the information and had more positive perceptions of the benefits from taking medicines and intention to adhere than those reading the PIs. Patients' perceptions of risks after reading both leaflets were moderate (median score = 5.0), with the PIL group having slightly more concern about risks than the PI group.

CONCLUSION

The PILs showed superior effectiveness to the PIs in enhancing knowledge about medication safety, providing greater satisfaction with the information, and positive perceptions of benefit and intention to comply with the medications. PILs should be provided more frequently to patients receiving medicines than PIs.

Development and psychometric validation for evaluating written medicine information in Thailand: The Consumer Information Rating Form

OBJECTIVE

To translate and validate the consumer information rating form (CIRF) for use in Thai populations.

DESIGN

The development of the CIRF was carried out in two phases: translation process and cognitive interview, and psychometric testing.

SETTING

A university hospital and a tertiary hospital in northeast Thailand.

PARTICIPANTS

150 outpatients from medicine department: 30 for phase 1 and 120 patients for phase 2 study.

METHODS

The CIRF was translated with cultural adaptation into Thai using cognitive interview technique in a sample of outpatients. A larger sample of outpatients then completed the CIRF in relation to either a package insert (PI) or a patient information leaflet (PIL) for one of three medicines: atorvastatin, celecoxib and metformin. Construct validity was assessed using principal component analysis (PCA) and internal consistency using Cronbach's α coefficient. Known group validity was assessed by comparing mean consumers' ratings for PIs and PILs.

RESULTS

Thirty participants engaged in the cognitive interview and 120 participants completed the CIRF. The PCA found the 17 items of the CIRF were extracted into three factors: comprehensibility, utility and design quality scales, mirroring the original. Cronbach's α for the overall scale (0.904) indicated good internal consistency. Known-group validity demonstrated significant differences in consumers' rating between PIs and PILs for almost all items (p<0.001).

CONCLUSION

Thai version of CIRF had acceptable validity and reliability for Thai consumers' ratings of written medicine information. The CIRF could be of practical use in the process of developing medicine information to ensure consumers' comprehension and their usefulness.

Evaluation of Patient's Knowledge of Atorvastatin Information in Patient Information Leaflets: A Pre-Post Intervention Study in Thailand

PURPOSE

This study aimed to evaluate the effect of using atorvastatin PIL on patients' medication knowledge, perceptions of the PIL usefulness, their anxiety about the medication, and factors related to these aspects.

PATIENTS AND METHODS

A pre-post intervention study was conducted in outpatients at a university hospital. Patients prescribed atorvastatin were enrolled using systematic random sampling. Participants were asked to complete Self-Administered Questionnaire to assess atorvastatin knowledge at baseline. An atorvastatin-PIL produced by the manufacturer was introduced to the participants as the intervention. One month after receiving the PIL, the participants were re-assessed. Ten questions were developed to assess atorvastatin knowledge and visual analog scale (VAS) was used to assess perceived benefits of using the PIL and patient anxiety about the medication. Multiple linear regression was used to assess the related factors.

RESULTS

Of 450 questionnaires distributed, 370 were returned. Atorvastatin knowledge significantly increased with mean score of 5.06±1.92 at baseline to 8.34±1.79 at 1-month after intervention. Reading all sections of the PIL (p=0.017) and working for civil service (p=0.006) were associated with higher knowledge scores at baseline and after intervention. Low educational level was associated with lower knowledge scores at baseline (p=0.002), but experience of allergy (p=0.042) was associated with higher knowledge scores after the intervention. Patients had high level of perceived usefulness from the PIL (average scores=8.87±1.83) and low level of anxiety (average scores=3.69±3.06). Reading all sections of the PIL (p=0.007) and taking more than 5 medications (p=0.012) were related to perceived usefulness of the PIL. Females (p<0.001) and herbal supplement users (p=0.048) were related to anxiety about the medication.

CONCLUSION

PILs could improve medication knowledge in patients. Patients' perceptions of benefits of PILs were high and anxiety about medication was low. Use of PILs should be encouraged to improve patients' knowledge and appropriate use of medications.

Patients' Experiences and Perspectives of Receiving Written Medicine Information About Medicines: A Qualitative Study

PURPOSE

Written medicine information informs patients about the benefits and risks of medicines and supports their safe and effective use. In Thailand, patient information leaflets (PILs) are not obligatory and therefore not routinely supplied. This study aimed to explore the experiences and information needs of patients, their views on PILs and the likely impact of PILs on their knowledge, perceptions and behaviors towards medicines. These factors are important to establish the value of PILs.

METHODS

Semi-structured interviews with outpatients who received simvastatin or atorvastatin were conducted exploring their experiences of receiving medicine information, their views on the utility of and need for PILs, the impact of PILs on their behaviors, and recommendations for how PILs could be improved. All interviews were audio-recorded, transcribed verbatim, and analyzed using a framework approach.

RESULTS

Thirty interviews were conducted from which four themes emerged: experience of receiving medicine information, views of package inserts and PILs, impact of PILs on knowledge, perceptions and behaviors, and patients' need for medicine information. Most participants received verbal information from healthcare professionals, as well as written information. Verbal information was perceived as being particularly useful to inform about changes to medicine regimens or the long-term adverse effects of medicines. Patients perceived that the PILs had influenced their knowledge about medicines, and also their behaviors including safety awareness, adherence, and engagement with healthcare professionals. Participants suggested that the information in electronic format could provide an additional resource. Some changes to improve the content and general format of the PIL were identified.

CONCLUSION

PILs are perceived as useful by patients and met their information needs, although they were viewed as an adjunct to verbal advice provided by healthcare professionals. PILs influenced patients' medicine taking behaviors and encouraged sharing of information with their physicians.

Survey of healthcare professionals' practices, expectations, and attitudes towards provision of patient information leaflets in Thailand

Background Patient information leaflets are an important source of medicine information for patients. In Thailand, there is a lack of studies exploring activities of healthcare professionals and their attitudes towards provision of patient information leaflets. Objectives This study aimed to survey healthcare professionals' practices on provision of medicine information, expectations of, attitudes towards provision of patient information leaflets and factors influencing these. Setting Two university hospitals in Thailand. Methods A self-completion questionnaire was distributed to chiefs of departments for further distribution to staff. A stratified sample of physicians and nurses was invited, while all pharmacists were invited to ensure sufficient numbers for comparison. Main outcome measure Healthcare professionals' practices on provision of medicine information, expectations of, attitudes towards provision of patient information leaflets. Results Of the total 981 healthcare professionals invited, 493 responded (50.3% response rate). The number of respondents aware of patient information leaflets was 270 (57.6%). Of these, only 44.4% had ever given patient information leaflets to patients. Pharmacists provided patient information leaflets more frequently than other healthcare professionals. The expectation for patient information leaflets to be available was high; mean score 7.9 ± 2.31 of possible 10. Most respondents had positive attitudes towards providing patient information leaflets to patients (58.2%). Respondents who were aware of patient information leaflets availability were more likely to have a positive attitude (OR 0.543, p = 0.002). Level of education, time spent in direct care and being aware of patient information leaflets were factors associated with healthcare professionals' attitudes. Conclusion Limited number of healthcare professionals had provided patient information leaflets to patients but most had positive attitudes regarding the usefulness of patient information leaflets for patients. Increased availability and use of patient information leaflets should be promoted.

Experiences and Views of Medicine Information Among the General Public in Thailand

PURPOSE

Written and electronic medicine information are important for improving patient knowledge and safe use of medicines. Written medicine information in Thailand is mostly in the form of printed package inserts (PIs), designed for health professionals, with few medicines having patient information leaflets (PILs). The aim of this study was to determine practices, needs and expectations of Thai general public about written and electronic medicine information and attitudes towards PILs.

PATIENTS AND METHODS

Cross-sectional survey, using self-completed questionnaires, was distributed directly to members of the general public in a large city, during January to March 2019. It explored experiences of using information, expectations, needs and attitudes, the latter measured using a 10-item scale. Differences between sub-groups were assessed, applying the Bonferroni correction to determine statistical significance.

RESULTS

Of the total 851 questionnaires distributed, 550 were returned (64.2%). The majority of respondents (88%) had received PIs, but only a quarter (26.2%) had received PILs. Most respondents (78.5%) had seen medicine information in online form. High educational level and income increased the likelihood of receiving PILs and electronic information. The majority of respondents (88.5%) perceived PILs as useful, but 70% considered they would still need information about medicines from health professionals. Indication, drug name and precautions were the most frequently read information in PIs and perceived as needed in PILs. Three-quarters of respondents would read electronic information if it were available, with more who had received a PIL having previously searched for such information compared to those who had not. All respondents had positive overall attitudes towards PILs.

CONCLUSION

Experiences of receiving PILs and electronic medicine information in Thailand are relatively limited. However, the general public considered PILs as a useful source of medicine information. Electronic medicine information was desired and should be developed to be an additional source of information for consumers.

Practices of healthcare professionals in communicating with nonsteroidal anti-inflammatory drug users in Thailand: a qualitative study

OBJECTIVE

This study aimed to explore practices among healthcare professionals in nonsteroidal anti-inflammatory drug (NSAID) information provision.

METHODS

In-depth interviews were conducted with orthopaedic physicians (OPs), hospital and community pharmacists (CPs) in northeastern Thailand. Ten hospitals and 20 pharmacies in five provinces were purposively selected. Interviews followed a topic guideline, were audio-recorded, transcribed verbatim and analysed using a framework approach.

KEY FINDINGS

Fifty-one participants were involved: 13 OPs, 20 hospital pharmacists and 18 CPs. Four main themes emerged: general information, safety information, differences between new and regular NSAID users and non-selective and selective NSAID users. Pharmacists mostly provided information on administration and indication. While all three groups informed of adverse effects, this was selective, related to factors including trading, time available, patients' age and perceived ability to understand. Gastrointestinal adverse effect information was most commonly provided, with other side effects, drug interactions and need to monitor for adverse effects rarely mentioned. Variation was reported in provision of safety information depending on whether patients were using selective or non-selective NSAIDs, and new or long-term users.

CONCLUSIONS

The content and frequency of NSAID information provision varied between health professionals. Greater awareness of NSAID risks is essential; therefore, strategies to improve information provision to Thai patients are desirable.

Development and evaluation of user-tested Thai patient information leaflets for non-steroidal anti-inflammatory drugs: Effect on patients' knowledge

INTRODUCTION

Thai patients do not routinely receive patient information leaflets (PILs) with medicines, so awareness of safety issues is low. This study aimed: i) to develop Thai PILs for NSAIDs and subject these to user-testing, and ii) to assess the potential value of PILs from the patient perspective and effect on patient knowledge.

METHODS

Four PILs for NSAIDs were developed and subjected to multiple rounds of user-testing by the general public. Self-administered questionnaires were distributed to orthopaedic out-patients prescribed one of these NSAIDs, assessing knowledge before and after providing a PIL. The follow-up questionnaire also sought use of and views on the PILs using a visual analogue scale (VAS).

RESULTS

1,240 baseline questionnaires were completed; only 13.5% of patients had good knowledge. 688 patients returned follow-up questionnaires (55.5%), of whom75% had good knowledge. In patients completing both questionnaires, mean knowledge score increased from 6.22±1.40 to 8.42±1.41 (p<0.001). Patients with high educational levels had high baseline scores (OR = 2.728) and showed greatest improvement in knowledge (OR = 5.628). 90% (625) of follow-up respondents indicated they read all information in the PILs. All also agreed that these PILs should distributed to all patients taking NSAIDs. The median VAS score for usefulness was 9.3 (IQR 8.6-10.0).

CONCLUSIONS

User-testing of PILs was feasible in a Thai population and enabled the development of acceptable and desirable PILs. PILs could improve patients' knowledge about their medicine, particularly among those with higher educational level. User-tested PILS could meet the need for more written medicine information.

Survey of outpatients' use and needs of patient medicine information leaflets in Thailand

Background Patient information leaflets are important sources of medicine information. Regulations of patient information leaflet provision varies among country. Little is known regarding patients' behavior and expectation on use of patient information leaflets. Objectives To explore patients' use of either package inserts or patient information leaflets and to survey patients' expectations and needs on use of patient information leaflets and their associated factors. Setting Two university hospitals in Thailand. Methods Cross-sectional study using self-administered questionnaires distributed to outpatients over a 3-month period. Participants were selected through systematic random sampling. Logistic regression was used for data analysis. Main outcome measure Patient use of medicine information. Visual Analogue Scale scores for patient needs and their expectation of knowledge gains from using patient information leaflets. Results The response rate was 77.0%. Most respondents had received package inserts (91.3%) with 59.4% reporting that they sometimes read them. While most respondents had not previously known about patient information leaflets (75.9%), 97.3% reported that patient information leaflets would be useful. Respondents scored their needs and expected knowledge gains after reading patient information leaflets as 9.68 ± 0.97 and 9.64 ± 0.99, respectively. Previous experience with package inserts was associated with increased patient need scores (p = 0.002) and higher expected knowledge gains from use of patient information leaflets (p = 0.037). In addition, patients who had not previously known about patient information leaflets had higher expectations of knowledge gains (p = 0.016). Conclusion Overall, patients showed good behavior on reading package inserts. Although many patients were not previously aware of patient information leaflets, they realized the importance. Hence, patient information leaflets should be developed and provided to Thai patients.

Confidence and accuracy in identification of adverse drug reactions reported by outpatients

Background Patient reporting of adverse drug reactions (ADRs) could supplement the existing reporting system and contribute to early detection of ADRs. The confidence in ADR identification and their attribution of ADRs were limited to outpatients. Objective To determine the type and frequency of ADRs reported by outpatients, to evaluate confidence and accuracy in ADR identification as well as contributing factors. Setting University hospital in northeastern Thailand Method Cross-sectional study using questionnaires distributed to 500 outpatients who claimed to have experienced an ADR. Confidence in identifying ADRs was measured by visual analogue score (VAS), while accuracy of reported ADRs was determined using Naranjo algorithm and WHO criteria. Main outcome measure Number and type of ADRs, confidence rating and accuracy category. Results In total, 390 outpatients completed the questionnaire (response rate = 78.0%). Rash (19.0%), nausea/vomiting (7.4%), and dizziness (5.8%) were the top three reported ADRs. Sixty-one percent of respondents rated their level of confidence in identifying ADRs as high (VAS 9.2 ± 0.95), which was associated with having underlying diseases (OR 1.93), low number of reported symptoms (OR 0.38) and severe ADRs (OR 1.33). Causality assessment was classified as true ADRs in 90.0% and 88.9% of cases, using Naranjo algorithm and WHO criteria, respectively. Respondents with low number of reported symptoms (OR 0.27) and high level of confidence had greater accuracy in ADR identification (OR 1.11). Conclusion The outpatients reported a high proportion of potential ADRs with high confidence and accuracy. Patient reporting of ADRs has potential to support the pharmacovigilance system.

Physicians' communication of risks from non-steroidal anti-inflammatory drugs and attitude towards providing adverse drug reaction information to patients

RATIONALE, AIMS, AND OBJECTIVES

Nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently prescribed for orthopaedic conditions, therefore this study aimed to explore orthopaedic physicians' perceptions of their role in NSAID-risk communication, their attitudes towards the necessity of informing patients about adverse drug reactions (ADR), and factors associated with these.

METHODS

Self-administered questionnaires were mailed to all 206 orthopaedic physicians working at hospitals in Northeastern Thailand. Attitudes were assessed using 17 statements and total scores classed as poor, moderate and good attitude.

RESULTS

Sixty-six questionnaires were returned (32.04%). The responses showed that 75% of physicians claimed to communicate NSAID ADR information, more frequently about gastrointestinal (GI) complications, than about renal and cardiovascular (CVS) complications. ADR management (36%) and monitoring (30%) were not frequently communicated. The time spent with patients was associated with provision of ADR and monitoring advice. Renal function was the risk factor of greatest concern for prescribing any NSAID, followed by history of GI complications, and allergy for non-selective NSAIDs, and history of CVS diseases and age for selective COX-2 NSAIDs. Most physicians (41) had moderate attitude towards providing information and 24 good attitude. Fewer physicians working in tertiary hospitals than general and community hospital physicians considered that time limitations prevented counseling and that patient information leaflets offered easily accessible information. Additionally, more physicians who did not inform patients about ADRs agreed that ADR communication can lead to anxiety and discontinuing treatment.

CONCLUSION

The study indicates that, although orthopaedic physicians had positive attitudes towards providing ADR information to patients, improvement is needed in communicating NSAID risk information.

Experiences of and attitudes towards receiving information about non-steroidal anti-inflammatory drugs: a cross-sectional survey of patients in Thailand

OBJECTIVE

To determine sources of information about NSAIDs used by out-patients, factors related to receipt of information and patient attitudes towards receiving safety information.

RESEARCH DESIGN AND METHODS

Cross-sectional survey, using self-completed questionnaires distributed directly to 500 outpatients prescribed any NSAIDs from an orthopaedic clinic in Thailand, over a 4-month period.

RESULTS

There were 548 patients approached and 474 completed questionnaires returned (94.8%). The most frequent aspects of medicines information that were provided related to administration (97.2%), mostly provided by pharmacists, and indication (85.8%), mostly provided by physicians. Information on identifying, monitoring and managing adverse effects was received by fewer than 50% of patients. Safety information was received significantly more frequently by younger patients (P<0.01), those using non-selective COX-2 inhibitors (P<0.001), intermittent NSAIDs (P<0.05) and fewer concomitant medicines (P<0.05). Only 14.1% patients used additional information sources. Attitudes towards receiving medicines safety information were positive. Most patients agreed they should know about ADRs (98.1%) and receive information leaflets with first prescription (96.8%).

CONCLUSIONS

Patients received medicines information mostly from healthcare professionals, but safety information was limited. Type of NSAIDs, regularity of NSAID use and age affected receipt of safety information about NSAIDs. Provision of more medicine information is needed, particularly written documents.

Experiences relating to adverse drug reactions in the community: a cross-sectional survey among patients and the general public in Thailand

OBJECTIVE

To determine the frequency and characteristics of adverse drug reactions (ADRs), experiences of receiving and desire for information about medicines, and attitudes toward ADR knowledge and reporting among the community-dwelling Thai population.

METHODS

A cross-sectional self-administered survey conducted during October 2013 to December 2014 by convenience sampling. The study was conducted in three settings in the second-largest city, North-eastern Thailand: primary care units, community pharmacies and public areas.

RESULTS

Of 2400 respondents, 414 (17.3%) reported experiencing an ADR; two-thirds of which involved mild symptoms (66.7%) and 55.6% occurred within the last year. Self-reported ADR knowledge was low (4.1 ± 2.5 on a scale of 0 to 10). Pharmacists and physicians were the most common sources of information about medicines, but only 28.5% had received information about ADRs. Over 40% wanted information about ADRs and drug interactions, with healthcare professionals and information leaflets being desirable sources. The majority of individuals had positive views towards both receiving information and reporting their ADR experiences.

CONCLUSIONS

To enable the Thai public to report their experiences of ADRs more effectively, they require more medicines information. Information leaflets should be more widely available, while healthcare professionals should provide more detailed information of ADRs.

Medicine information leaflets for non-steroidal anti-inflammatory drugs in Thailand

BACKGROUND

The importance of promoting the use of patient-oriented medicines leaflets is recognized in many countries. Leaflets should include basic information plus specific warnings, and be provided with all medicines, but there is little attempt at enforcement of these requirements in Thailand.

OBJECTIVE

To determine content and availability of Thai information leaflets for nonsteroidal anti-inflammatory drugs (NSAIDs).

METHODS

Leaflets for all NSAIDs available for purchase from 34 pharmacies in a large city were evaluated against a checklist and number of leaflets assessed against number of medicine packs available in each pharmacy.

RESULTS

Of the 76 leaflets for ten different NSAIDs, 67 (88 %) were for locally manufactured products. Only 22 % of 76 leaflets were sufficient in number for distribution with medicines, while only 4 % had patient-oriented leaflets. No leaflet covered all topics in the checklist. Less than half included safety information, such as contraindications (46 %), precautions (47 %), and adverse drug reactions (34 %). Locally-produced leaflets provided less information than those for originator products and no leaflet included all the warnings required by Thai regulations.

CONCLUSION

This study illustrates the variable availability and quality of NSAID information leaflets. The lack of accessible essential information about medicines in Thailand requires urgent attention to enable patients to minimise adverse reactions.

Initial development and testing of an instrument for patient self-assessment of adverse drug reactions

PURPOSE

To develop and conduct preliminary testing of a causality assessment tool for patients, for potential use in encouraging both discussions with clinicians about suspected adverse drug reactions (ADRs) and reporting to authorities.

METHODS

Ten causality statements, developed from qualitative studies involving patients, with a scoring system allowing categorization, were embedded in a questionnaire which also included a symptom checklist and additional details about one suspected ADR and medicine, selected for causality assessment. Patients with experiences of suspected ADRs were involved in cognitive interviews (15), piloting (20) and psychometric testing (120). Test-retest reliability, construct validity and criterion-related validity were evaluated, through repeated causality assessment, comparison with a visual analogue scale assessing certainty of causality and comparison with causality assessment using World Health Organization-Uppsala Monitoring Centre (WHO-UMC) criteria, respectively. The study involved outpatients at a university hospital in northeast Thailand.

RESULTS

Ninety-eight patients completed causality assessment twice: both causality scores (Spearman rs  = 0.715; p < 0.001) and causality classification [percentage of positive agreement (PPA) = 68.4; κ = 0.419; p < 0.001] showed satisfactory reliability. Causality scores were positively correlated with certainty of causality (Spearman rs  = 0.556; p < 0.01). There was moderate agreement against WHO-UMC criteria [PPA = 70.4; κ = 0.440; p < 0.001]. Of the 91 completing an evaluation, 88% agreed that the tool should be used routinely, 78% agreed that it gave them useful results and 80% agreed that it was easy to use.

CONCLUSIONS

This novel instrument has satisfactory psychometric properties and was acceptable to Thai patients, but it requires further testing. It has potential for use in supporting patients with suspected ADRs to discuss these with health professionals, and perhaps to report directly.

Management for improving patients' knowledge and understanding about drug allergy

BACKGROUND

Drug allergy a serious adverse drug reaction commonly concerned in healthcare practice. Inadequate documentation and communication between health providers, and limited health literacy and knowledge in patients could contribute to the re-occurrence of allergic reactions.

OBJECTIVE

To evaluate the effectiveness of initiatives aiming to improve patients' knowledge, understanding and behavior in preventing recurrent drug allergy.

METHODS

A before-and-after study was conducted at an 800-bed university teaching hospital, involving patients with a history of drug allergy. Questionnaires, completed at baseline and one month after receiving information were used to compare knowledge and understanding of drug allergy and behaviors in relation to drug allergy cards. Patients in Group 1 received a brochure only, but patients in Group 2 also received a pharmacist counseling intervention in addition to the brochure. Outcomes were evaluated within intervention group and between intervention groups.

RESULTS

The study included 299 (30.4%) and 100 patients (100.0%) in Groups 1 and 2 respectively who completed the baseline questionnaire, of whom 179 (59.8%) and 96 (96.0%) completed the follow-up questionnaire. At baseline, higher educational levels and possession of a drug allergy card were significantly associated with better knowledge about drug allergy. After intervention, Group 2 had significantly greater increases in mean overall knowledge scores than Group 1 (p<0.01) and also greater increases in the proportions self-reporting carrying and presenting drug allergy cards (p<0.05 and p<0.01).

CONCLUSIONS

Pharmacist counseling plus brochure may be more effective than brochure alone in promoting patients' knowledge of drug allergy and drug allergy card importance.

Statin adverse effects: patients' experiences and laboratory monitoring of muscle and liver injuries

BACKGROUND

Although statins have great benefit on the prevention of cardiovascular diseases with limited adverse effects (AEs), little is known about patients' contribution of AE reports in clinical practice.

OBJECTIVES

To explore patients' experiences of statin AEs and related laboratory monitoring in clinical practice.

SETTING

Outpatient clinics of two University hospitals in northeast Thailand.

METHODS

Generic symptom checklist questionnaires for self-reporting AEs were distributed to patients prescribed simvastatin, atorvastatin, or rosuvastatin at outpatient clinics. Clinical information was obtained from medical records. Reported symptoms were assessed for causality considering previously known statin AEs, concomitant diseases and drugs.

MAIN OUTCOME MEASURE

Potential statin AEs reported by patients and monitoring of laboratory parameters related to musculoskeletal and liver disorders.

RESULTS

Of the total 718 valid responses, 76.0 % of patients reported at least one symptom, most of which (69.0 %) were probable/possible statin AEs. Musculoskeletal and liver-related symptoms were reported by 283 (39.4 %) and 134 patients (18.7 %), respectively. Probable/possible AEs were categorized in 56.7 % of their musculoskeletal and gastrointestinal symptoms. Majority of patients had at least one laboratory test on initiation of (64.8 %) and during statin treatment (61.8 %). Patients taking atorvastatin or rosuvastatin, and patients with history of chronic renal diseases were more likely to have creatine kinase (CK) monitored on initiation of and during statin treatment. Additionally, taking drugs which could potentially increase muscle injury (OR 1.929, P < 0.01) and self-reporting of musculoskeletal symptoms (OR 1.805, P < 0.01) were associated with CK monitoring during statin treatment. Reporters of musculoskeletal symptoms also had significantly higher mean CK level than those not reporting any musculoskeletal symptoms (207.35 ± 155.40 vs. 143.95 ± 83.07 U/L, respectively; P = 0.037). Patient reporting of liver AEs was not related to alanine aminotransferase (ALT) level and monitoring, however, prior history of liver disorders was significantly associated with monitoring of ALT on initiation of and during statin treatment (OR 5.745 and OR 23.063, respectively; P < 0.01).

CONCLUSION

Many patients experienced at least one possible adverse effects on a statin. The findings suggest that laboratory monitoring is relatively selective in relation to risks and patient-reported adverse symptoms.

Hospital pharmacists' roles and attitudes in providing information on the safety of non-steroidal anti-inflammatory drugs in Thailand

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for patients to manage pain and inflammation, especially in older adults. Failure to cope with some adverse drug reactions (ADRs) of NSAIDs could lead to more serious symptoms, therefore, providing useful information about medicine is an important step in protecting patients from developing serious ADRs. The pharmacy service should be a frequent source of medicine information for patients, however in Thailand, little is known about pharmacists' provision of safety information to patients for management and prevention of these ADRs.

OBJECTIVE

Aims of this study were to determine Thai hospital pharmacists' roles in providing drug safety information and to assess their attitudes towards the importance of giving drug safety education to patients.

SETTING

All government hospitals in north-eastern Thailand.

METHODS

This study was a cross-sectional survey. A total of 761 pharmacists in 287 hospitals in north-eastern Thailand were selected by stratified random sampling. Self-administered questionnaires were sent by post, with two reminders.

MAIN OUTCOME MEASURES

Proportion of hospital pharmacists providing ADR information on NSAIDs to patients, factors affecting this provision, and pharmacist attitudes towards drug safety education for patients.

RESULTS

The response rate was 54.8% (N = 417), the majority of respondents worked in community hospitals (57.2%). A total of 347 pharmacists (83.6%) had informed patients about ADRs, although less than half had informed patients about ADR monitoring and management (36.6% and 44.1% respectively). The proportion of time spent in direct patient contact, type of hospital, and other routine work were associated with the frequency of drug safety information provision. Pharmacists had moderately good attitudinal scores towards drug safety education (62.2 ± 5.4), with significantly higher scores found in those who provided most ADR information to patients (60.3 ± 5.2 vs. 62.6 ± 5.4, P = 0.002). The majority (82.2%) agreed that patient information leaflets should be provided.

CONCLUSIONS

Thai hospital pharmacists' provision of ADR information for NSAIDs may occur less frequently than is desirable. However, their positive attitude towards provision of ADR information suggests that drug safety education by pharmacists should be routinely provided to patients, particularly patients at high risk of NSAID use.

Patient reporting of suspected adverse drug reactions to antiepileptic drugs: factors affecting attribution accuracy

This study was aimed to assess the frequency and number of suspected ADRs reported by patients taking antiepileptic drugs (AEDs) and to explore the factors that may affect patients' symptom attribution accuracy. A validated questionnaire containing an extensively checklist of symptoms was distributed to outpatients prescribed one or more AEDs. Data on concomitant drugs and diseases were obtained from outpatient records. All symptoms identified were assessed for causality. Of 1388 questionnaires distributed to 1214 patients, 830 completed questionnaires were returned (59.8%) from 727 patients. In total, 7815 symptoms were identified on 757 questionnaires (91.2%). Symptom severity ratings were positively related to the number of symptoms reported (p=0.003). Causality assessment found that 71.9% of the symptoms were 'true' ADRs and 28.1% were 'false' ADRs. Attribution accuracy was primarily influenced by the number of symptoms identified and indication for AED therapy, fewer symptoms and use for non-epilepsy indications being associated with greater attribution accuracy.

Patient self-eports of potential adverse drug reactions

Focal points

Patient self-reporting of potential adverse drug reactions to non-steroidal anti-inflammatory drugs in Thailand

OBJECTIVES

To validate and pilot in Thailand a questionnaire to enable patients to identify and report symptoms perceived as potential ADRs from NSAIDs. To determine the questionnaire's usefulness in enabling Thai out-patients to report potential ADRs. To determine the frequency with which symptoms patients reported were recorded by health professionals and the frequency of ADRs to these drugs reported to the APRM Centre. To assess whether patients reported symptoms from non COX-selective inhibitors and COX-2 selective NSAIDs with different frequencies.

SETTING

Out-patient departments (OPD) of a University teaching hospital in North-East Thailand.

METHOD

A questionnaire which incorporated an extensive symptoms checklist, developed and validated in English, was translated, piloted and validated in Thai. This was distributed to patients receiving one of five NSAIDs. Causality assessment of the symptoms reported was undertaken by a pharmacist, using data on concomitant medicines and disease states from OPD records.

OUTCOME MEASURES

Frequency and type of symptoms reported by patients, recording of these in OPD records, reports sent to APRM Centre.

RESULTS

Piloting found that patients were able to understand the questionnaire, but were unaware of drug names. A response rate of 42% was obtained: 694 usable questionnaires were returned out of 1,654 distributed. Overall 73% of respondents reported at least one symptom perceived to be an ADR. Sixty percent of symptoms reported were classed as probably or possibly an ADR. Fewer symptoms per patient were reported by those taking COX-2 selective inhibitors (3.5) than those taking non-selective NSAIDs (5.5), although there were no differences in the frequency of GI symptoms reported between these two sub-classes, which may relate to other factors, such as age, previous GI problems and prescription of protective ulcer-healing therapy. Only 5% of symptoms were recorded in OPD records and reporting of ADRs to these drugs to the APRM Centre of the Thai FDA during the study was very limited.

CONCLUSION

Thai out-patients were willing and able to complete questionnaires regarding potential ADRs. The questionnaire could form part of routine out-patient monitoring, aiding identification of ADRs, and may help to increase ADR reporting in Thailand.

Hospital pharmacists' activities and attitudes regarding the Thai safety monitoring program for new drugs

PURPOSE

To determine the knowledge, attitudes and practices of Thai hospital pharmacists concerning the safety monitoring programme and reporting of adverse drug reactions to the Thai Food and Drug Administration.

METHODS

Postal questionnaires distributed to 414 Thai hospitals, including all larger hospitals and a proportion of small community hospitals, for completion by the pharmacist responsible for ADR reporting to the Thai FDA.

RESULTS

The response rate was 63.0% (n = 262) with most respondents (190; 72.8%) being directly responsible for ADR reporting. Most hospitals (251; 96.5%) designated at least one pharmacist as responsible for ADR reporting, but only 164 (62.8%) respondents were aware of the SMP. Only 15 respondents out of the 56 working in hospitals using new drugs had established reporting via the SMP. Uncertainty in ascribing causality, lack of co-operation between health professionals and lack of staff were identified as barriers to reporting. Most respondents agreed that enhanced co-operation and improvements needed in hospital systems were required. Less than half agreed that the reporting system was simple and the majority agreed that changes were required to the SMP reporting mechanisms.

CONCLUSIONS

Thai hospital pharmacists have positive attitudes towards reporting of ADRs, but not all are aware of the SMP for new drugs. Few hospitals use new drugs and even less are involved in active reporting of suspected ADRs via the SMP. To increase reporting rates, potential difficulties with the organization of reporting via the SMP and the potential role of hospital pharmacists in ADR identification should be investigated further.

Adverse drug reaction monitoring: comparing doctor and patient reporting for new drugs

PURPOSE

To compare the frequency of adverse drug reactions (ADRs) recorded by doctors with perceived ADRs reported by patients during hospitalization and post-discharge and to compare both to formal reporting in Thailand.

SETTING

Tertiary teaching hospital, North-East Thailand.

METHODS

Over a 6-month period doctors were requested to record ADRs to 13 recently marketed index drugs, occurring during hospitalization and after discharge, using specific forms. Patient perceived ADRs were detected by daily pharmacist interviews during hospitalization and a symptom checklist questionnaire after discharge.

RESULTS

In total, 203 in-patients were prescribed an index drug and interviewed. Doctors recorded 13 ADRs in these patients, resulting in seven drugs being stopped. In-patients reported 15 further symptoms, but 12 were assessed as unlikely to be an ADR. Of 160 patients who continued the index drug after discharge, 152 accepted questionnaires and 88 (58%) were returned. Patients identified 249 symptoms, of which the pharmacist assessed 190 (76%) as probably or possibly ADRs, using a previously developed method. Only 26 symptoms were noted in out-patient department (OPD) records, although most patients claimed to have informed doctors about them. Doctors recorded only five symptoms on ADR forms, all associated with drug discontinuation. During the study period, four reports were received by the Thai FDA on these 13 drugs, none from this hospital.

CONCLUSIONS

Forms encouraging doctors to identify ADRs may be an effective method of increasing recording, particularly in the in-patient setting. A combination of methods including patient reporting may enable pharmacists to increase formal ADR reporting.

Randomized trial of atorvastatin in improving endothelial function in diabetics without prior coronary disease and having average cholesterol level

OBJECTIVE

The aim of this study was to determine whether HMGCoA reductase inhibitor with atorvastatin can modulate endothelial function in type II diabetics having average cholesterol and no prior cardiovascular disease.

MATERIAL AND METHOD

Type II diabetics, with no prior cardiovascular events and total cholesterol at admission of < or = 200 mg/dl or LDL < or = 140 mg/dl, were randomized to placebo (n = 20) or atorvastatin 20 mg daily (n = 22) for 30 weeks. Brachial artery endothelium-dependent dilatation or flow-mediated dilatation (FMD) and endothelium-independent dilatation or nitroglycerine-mediated dilatation (NTGMD) were measured at baseline and after thirty weeks of treatment.

RESULTS

Baseline clinical characteristics were similar at admission in both groups. After thirty weeks of treatment, the FMD did not significantly change in either the atorvastatin or placebo group (4.11 +/- 1.05% to 3.01 +/- 1.27% vs 5.75 +/- 1.93% to 6.45 +/- 1.41%, respectively; p = 0.46 by analysis of covariance). Similarly, the NTGM did not change in either group.

CONCLUSION

The addition of HMGCoA reductase inhibitor with atorvastatin did not improve endothelial function in type 2 diabetes having average cholesterol with no prior cardiovascular disease, despite an improvement of the lipid profile.

Patient reporting of adverse drug reactions: useful information for pain management?

BACKGROUND

Patients' perceptions of adverse effects caused by the medicines they are prescribed may influence how they use these medicines. Little is known about patients' perceptions of the adverse effects of specific drugs in everyday use and whether these differ from those identified by clinical trials and standard post-marketing surveillance methods.

AIM

To compare reports of perceived adverse drug reactions (ADRs) obtained directly from patients taking tramadol to those found in clinical trials and two methods of post-marketing surveillance.

METHOD

Postal questionnaire distributed to 1048 patients who had a prescription for tramadol dispensed over a 3-month period.

RESULTS

Most (84%) of the 344 respondents reported at least one symptom perceived as an ADR to tramadol. Dry mouth, light-headedness and constipation were most commonly reported. Almost half (48%) rated their most bothersome symptom as at least moderate and 43% claimed to have reported symptoms to their doctor. Perceived problems had led 38 respondents to stop taking tramadol. The 10 most frequently reported symptoms were all previously reported ADRs to tramadol. Although relatively minor, all 10 also appeared in reports to the UK Committee on the Safety of Medicines (CSM) and in prescription event monitoring. For many symptoms, the estimated range of frequency was in line with published reports, but considerably higher than that of post-marketing surveillance methods.

CONCLUSIONS

Symptoms were reported by the majority of respondents and for many symptoms the frequency was high. Many patients did not report symptoms they perceived to be adverse effects to their doctor. The results indicate that patient perceptions of potential ADRs are relevant and should be an integral part of a pain management strategy.

Patient reporting of potential adverse drug reactions: a methodological study

AIMS

To develop a systematic generic method of enabling patients to report symptoms which they believe to be due to a particular prescribed drug.

METHODS

A piloted body system-based questionnaire was distributed to patients registered with 79 medical practices in Grampian prescribed one of nine recently marketed 'black triangle' drugs. These comprised four antidepressants, three antiepileptics and two analgesics. This requested respondents to identify any symptoms experienced over the previous year which they thought could be due to the 'black triangle' drug they had used. A sample of medical records was examined to compare symptoms recorded with those reported by patients. A classification system was developed for the study to enable the assessment of symptoms reported for their potential relationship to patients' drug therapy. All symptoms reported were classified, taking into account information provided by patients on their concomitant drugs and diseases. A specialist pharmacist independently re-classified a sample of the symptoms to validate the process.

RESULTS

A 36.3% response rate was obtained (837/2307) with 742 respondents (88.6%) reporting at least one symptom. The median per patient was 6.0 (range 0--71), with almost half (406, 48.5%) reporting fewer than five symptoms. Most symptoms (71.0%) were classified as being probably or possibly related to the drugs studied. Agreement between researcher and specialist on the classification of 75.3% of 716 symptoms was obtained (Kappa=0.563). Responses from patients prescribed antidepressant drugs were more likely to include symptoms potentially caused by these drugs (74.5% of all symptoms reported) than those from patients prescribed analgesics (67.4%) or antiepileptics (65.1%, chi2 = 23.858, d.f. = 2, P < 0.001). Patients reporting large numbers of symptoms were more likely to report some which were classed as unlikely to be an ADR or unattributable (chi2 = 80.587, d.f. = 3, P < 0.001). Of the 742 reporting symptoms in questionnaires, 402 (54.2%) claimed to have reported some or all of these to their doctor. Only 162 (22.6%) of 716 patient-reported symptoms were documented in the primary care medical records of 103 patients prescribed tramadol or venlafaxine.

CONCLUSIONS

Respondents were clearly willing to report symptoms, the majority of which were classed as possibly/probably related to the drugs studied. The results suggest that patients do not report all symptoms they suspect to be ADRs to their GP and that GPs do not record all symptoms which may be reported to them. The method could help to identify problems which patients perceive as being related to their drug therapy and contribute to increased ADR reporting.