Construct and concurrent validity of a patient-reported adverse drug event questionnaire: a cross-sectional study

Background: Direct patient-reported information about adverse drug events (ADEs) is important since it adds to healthcare professional-reported information about the safety of drugs. Previously, we developed an instrument to assess patient-reported ADEs in research settings. The aim of this study is to assess the construct and concurrent validity of the questionnaire.

Methods: Patients on at least an oral glucose-lowering drug completed the ADE questionnaire, the World Health Organization Quality of Life-BREF, and the Treatment Satisfaction Questionnaire for Medication (TSQM). The ADE questionnaire assesses ADEs for any drug that the patient uses. Construct validity was assessed by testing whether patients reporting an ADE had a lower general quality of life and physical health than those not reporting an ADE, using Mann-Whitney U-tests and t-tests (significance level

Results: We included 135 patients (mean age 64 years, 35% women). Patients who reported an ADE (N = 37) had a lower general quality of life and physical health than those not reporting an ADE (P

Conclusions: The construct validity of the patient-reported ADE questionnaire was sufficient for reporting any versus no ADE, but the concurrent validity was only partly demonstrated. Therefore, the questionnaire needs to be adapted before it can be used.