Correlation between the number of patient-reported adverse events, adverse drug events, and quality of life in older patients: an observational study.

Background: Previous studies on medication therapy management services, e.g. medication reconciliation and medication review, do not show consistent improvements in patient's health-related quality of life. However, these services can reduce adverse drug events.

Aim: To evaluate the correlation between health-related quality of life and adverse events/adverse drug events reported by patients.

Method: Older patients (≥ 65 years) with polypharmacy (≥ 5 medicines) admitted to orthopaedic or surgical wards were included. Patients were contacted post-discharge to evaluate patient-reported adverse events, health-related quality of life using the EuroQol questionnaire and self-perceived health status on a 5-point Likert scale. The outcomes were the correlation between health-related quality of life and the number of adverse events/adverse drug events, and potential predictors for these events. Spearman correlation and Poisson regression were used for data analysis.

Results: 102 patients were included. The correlation between health-related quality of life and adverse events was weak but significant (Spearman correlation coefficient: - 0.328, p = 0.001). No correlation was found for adverse drug events (- 0.064, p = 0.521). Self-perceived health status was a predictor for adverse events, not for adverse drug events. Health-related quality of life was neither a predictor for adverse events, nor for adverse drug events.

Conclusion: The correlation between the number of patient-reported adverse events, adverse drug events and health-related quality of life measured by the EuroQol was weak. There is a need for a questionnaire that includes the impact of medication use and is sensitive to outcomes that are affected by medication therapy management services.