Prevalence and risk factors of drug-related problems identified in pharmacy-based medication reviews

Abstract

Background: Medication safety is a major health concern, especially for older patients, in whom drug-related problems occur frequently as a consequence of polypharmacy and frailty, increasing the risk of adverse drug events.

Objective: To investigate the prevalence and types of drug-related problems in community pharmacies and to identify associated risk factors in order to adjust the focus of care.

Setting: 300 German community pharmacies in Saxony-Anhalt (Germany).

Method: In April 2015, community pharmacists conducted brown bag medication reviews for primary care patients, in which they identified and solved drug-related problems with patients or their physicians. Data from these reviews were analyzed, including frequency and nature of problems and their respective resolutions. Potentially inappropriate medications according to the PRISCUS list were identified by post hoc analysis. Risk factors for drug-related problems were determined using bivariate and multivariate logistic regression analysis.

Main outcome measure: Prevalence and risk factors of drug-related problems.

Results: 1090 medication reviews were conducted. On average, patients were 72.0 ± 9.1 years old and had 10.6 ± 3.7 medications, 62.0% (n = 676) presented a medication plan. Knowledge gaps about medications were detected in almost a third of patients (n = 345). Drug-related problems were identified in 84.2% (n = 918) of patients (in 3836 medications). Frequent problems concerned drug–drug-interactions (53.7%, n = 585) as well as drug use and adherence (46.7%, n = 509). Most problems (72.2%, n = 2769) were resolved between pharmacist and patient. Knowledge gaps and the number of drugs were independently associated with a higher risk of drug-related problems. For older patients, potentially inappropriate medications were a risk factor in bivariate, but not in multivariate analysis.

Conclusion: Pharmacists identified and resolved considerable rates of drug-related problems, suggesting that they are capable and well-positioned to conduct medication reviews. Knowledge gaps, the number of drugs, patient age and, in older patients, potentially inappropriate medications may indicate an increased risk for drug-related problems.