The impact of potentially inappropriate medicines on adverse clinical outcomes in the aged: A retrospective cohort study.

OBJECTIVES

To determine the association between potentially inappropriate medicines (PIMs) and mortality, hospitalization, adverse drug reactions and falls and specific inappropriate medicines which are associated with the outcomes.

METHODS

A retrospective cohort study was carried out using 1000 patients aged 75 years and above from the Clinical Practice Research Datalink. PIMs were estimated using the Screening Tool of Older People's Prescriptions. The association between PIMs and mortality, falls, adverse drug reactions, or hospitalization was determined using logistic regression analysis. Subgroup analyses were carried out by including an interaction term between different categories of PIMs and age, gender, and morbidity.

KEY FINDINGS

Data of 1000 people were analysed. 36 % were male and the mean age was 83 years. Adjusted odds ratios with their 95 % confidence intervals for association between PIMs and outcomes were: mortality 1.03(0.92 to 1.14), hospitalization 1.21(1.04 to 1.40), falls 1.30(1.12 to 1.51) and adverse drug reactions 1.20(1.02 to 1.40). The effect of PIMs on the outcomes was high in men and ≥ 86 years old and increased with an increasing number of PIMs. Tricyclic antidepressants, elemental iron in doses ≥200 mg daily, benzodiazepines, neuroleptics and long-acting opioids were associated with at least one of the outcomes.

CONCLUSION

Potentially inappropriate medicines are associated with hospitalization, falls and adverse drug reactions but not mortality.