Severity and Outcome of Adverse Drug Reactions Reported and Assessed by Patients and Pharmacist at Secondary Care...

The aim of the study was to describe Adverse Drug Reactions (ADRs) characteristics, compare ADR severity and outcomes as rated by patients and pharmacist, and identify factors associated with ADR severity.

A cross-sectional study was conducted among patients from a secondary care hospital in northeastern Thailand who had experienced an ADR within the previous year. A self-administered questionnaire was mailed to eligible patients. Patients assessed ADR severity their most severe ADR using visual analog scale. These rating were compared with pharmacist assessment based on the Hartwig and Siegel scale. Additional data on ADR severity and outcomes were collected by a research pharmacist from both electronic and paper medical records database. Causality assessment was performed by researcher pharmacist using the Naranjo's algorithm.

Of 745 invited patients, 381 completed the questionnaire. The mean patient-rated ADR severity score was 6.4 ± 2.94. According to patient ratings, ADRs were classified as mild (25.5%), moderate (32.0%), and severe (42.5%), whereas pharmacist assessments classified ADRs as mild (63.2%), moderate (33.9%), and severe (2.9%). The most commonly reported ADRs, classified by systemic organ class, were skin and subcutaneous tissue disorders (30.7%). Agreement between patient and pharmacist assessments was slight for ADR severity (κ = 0.043), and fair for ADR outcomes (κ = 0.212). Positive agreement between patient and pharmacist assessments was 31.2% for severity and 85.0% for outcomes. Higher patient-reported severity was associated with greater number of comorbidities, higher levels of anxiousness and bothersomeness, acute onset of ADRs, and greater confidence in identifying ADRs.

Patients tended to rate ADR severity higher than pharmacists, particularly when symptoms affected daily activities. Incorporating patient-reported assessments may support the timely recognition and communication of suspected ADRs while complementing, rather than replacing, professional clinical assessment.