Development and Initial Validation of a Patient-Reported Adverse Drug Event Questionnaire

Abstract

Background Direct patient reporting of adverse drug events (ADEs) is relevant for the evaluation of drug safety. To collect such data in clinical trials and postmarketing studies, a valid questionnaire is needed that can measure all possible ADEs experienced by patients. Objective Our aim was to develop and test a generic questionnaire to identify ADEs and quantify their nature and causality as reported by patients. Methods We created a draft list of common ADEs in layterms, which were classified in body categories and mapped to the Medical Dictionary for Regulatory Activities (MedDRA Ò ) terminology. Questions about the nature and causality were derived from existing questionnaires and causality scales. Content validity was tested through cognitive debriefing, revising the questionnaire in an iterative process. Feasibility and reliability were assessed using a Web-based version of the questionnaire. Patients received the questionnaire twice. Feasibility was assessed by the reported time needed for completion and ease of use. Reliability was calculated using Cohen's kappa and proportion of positive agreement (PPA) on: (1) any ADE at patient level; (2) similar ADEs at MedDRA Ò System Organ Class level; and (3) the same ADE at ADE-specific level.Results In the development phase, 28 patients with type 2 diabetes or asthma/chronic obstructive pulmonary disease (COPD) participated. Questions and answer options were rephrased, layout was improved, and changes were made in the classification of ADEs. The final questionnaire consisted of 252 ADEs organized in 16 body categories, and included 14 questions per reported ADE. A total of 135 patients using a median of five different drugs completed the Web-based questionnaire twice. The median completion time was 15 min for patients not reporting any ADE, and 30 min for patients reporting at least one ADE. Three quarters of the patients found the questionnaire easy to use. Test-retest reliability was acceptable at patient level (j = 0.50, PPA 0.64) and at MedDRA Ò System Organ Class level (j = 0.52, PPA 0.54), but was low at ADEspecific level (j = 0.38, PPA 0.38). Conclusion We developed a generic patient-reported ADE questionnaire and confirmed its content validity. The questionnaire was feasible and reliable for reporting any ADE and similar ADEs at MedDRA Ò System Organ Class level. Additional work is, however, needed to reliably quantify specific ADEs reported by patients.

Adverse drug event patterns experienced by patients with diabetes: A diary study in primary care

“…This was previously suggested as a more reliable way to question patients about ADEs. 11 The most important limitation is the small sample size in our study. 8 Regarding age, the participants appear similar to the average primary care diabetes population in the Netherlands but a higher proportion of males was included.…”

“…We asked patients to report any symptoms and subsequently asked whether they thought the symptom was related to any of the drugs they used. This was previously suggested as a more reliable way to question patients about ADEs …”

“…The percentage of patients reporting possible ADEs in our study is relatively high compared with previous studies. 1,2,11 This may in part be due to the follow-up period of 13 weeks, in which many short ADE episodes can be detected. More than 30% of the ADEs were for short episodes.…”

“…10 At the end of the period, patients completed a structured questionnaire to collect background characteristics and information about the drugs they had used in the study period, including prescription drugs and self-medication. 11…”

Evaluation of Potentially Drug-Related Patient-Reported Common Symptoms Assessed During Clinical Medication Reviews: A Cross-Sectional Observational Study

“…The probability of drug-related symptoms occurring can be derived from the frequencies for the side effects as given in the SPCs. However, the information in the SPC is based on clinical trials in specific patient populations with a short follow-up period, and thus may differ from frequencies in clinical practice [37, 38]. These differences may explain why muscle pain in statin users is more frequently reported in clinical practice than that in the SPCs.…”