Prevalence of potentially inappropriate medications at admission and discharge among hospitalised elderly patients with acute medical illness at a single centre in Japan: a retrospective cross-sectional study.

OBJECTIVE: To determine the prevalence of potentially inappropriate medications (PIMs) at admission and discharge among hospitalised elderly patients with acute medical illness in Japan.

DESIGN: A retrospective single-centre cross-sectional study.

PARTICIPANTS: Hospitalised patients aged 65 years or older admitted for pneumonia, heart failure, ischaemic stroke, acute coronary syndrome, chronic obstructive pulmonary disease or asthma, gastrointestinal bleeding, urinary tract infection or epilepsy from September 2014 to June 2016 who were still alive at discharge.

MAIN OUTCOME MEASURES: The primary outcome was the proportion of patients taking at least one PIM at admission and discharge. PIMs were defined based on the 2015 American Geriatric Society Beers Criteria. Temporal changes in the proportion of patients taking at least one PIM from admission to discharge were also evaluated.

RESULTS: During the study period, 689 eligible patients were identified. The median patient age was 82.0 years (IQR 76.0-88.0), 348 (50.5%) were men and the median number of medications at admission was 5.0 (IQR 3.0-8.0). The proportions of patients taking any PIMs at admission and discharge were 47.9% (95% CI 44.2% to 51.6%) and 25.1% (95% CI 21.9% to 28.4%), respectively. The proportion of patients taking any PIMs was significantly lower at discharge than at admission (reduction rate 0.48, 95%, CI 0.41 to 0.53).

CONCLUSIONS: A substantial proportion of hospitalised elderly patients with acute medical illness took PIMs at admission and discharge. These findings should be confirmed at other hospitals in Japan.