Abstract
BACKGROUND: Drug-related problems (DRPs) and polypharmacy are common among older adults with multimorbidity and limited functional capacity. These issues are associated with adverse outcomes and require targeted interventions. However, evidence regarding their prevalence and associated factors in home-based primary care settings—such as the ATDOM program in Catalonia—is still limited. METHODS: Aim: To determine the prevalence and types of DRPs and polypharmacy, and to identify factors associated with their presence in a home-based elderly population. Design: Observational cross-sectional study analysing data collected during a medication review project for ATDOM patients. Setting: Ten primary care centres in the Camp de Tarragona Primary Care Area, Catalonia, Spain. Participants: ATDOM patients aged ≥ 65 years undergoing pharmacological treatment. Measures: Sociodemographic and clinical characteristics (comorbidity, cognitive and functional status), medication data, and DRPs identified through pharmacist-led clinical medication review. Analysis: Descriptive statistics and bivariate and multivariable logistic regression analyses were conducted to examine associations between patient characteristics and the presence of DRPs and polypharmacy. DRPs were an independent variable for polypharmacy, whereas the number of drugs was an independent variable for DRPs. Ethics: Approved by the Research Ethics Committee of the Jordi Gol Primary Care Research Institute (19/141-P), Barcelona, Spain. RESULTS: We studied 923 patients with a mean age of 88.7 years (SD 6.7), and 72.6% of patients were women. Most had multiple comorbidities and high medication burden (56.3% polymedicated patients). The average number of prescribed drugs was 8.5 (SD 3.7). DRPs were identified in 78% of patients, with a mean of 1.7 (SD 1.4) DRPs per patient. The most common DRP subtypes were unnecessary indications and inappropriate drugs. In multivariable models, older age, greater number of prescribed drugs, diabetes and absence of cancer were associated with DRPs. Polypharmacy was associated with younger age, greater comorbidity, complex chronic condition, having DRPs, hypertension and respiratory system diseases. CONCLUSIONS: In the ATDOM program, patients with polypharmacy and DRPs associated with various factors are quite prevalent. These patients could be prioritized for pharmacist-led clinical medication review within multidisciplinary teams. An ongoing clinical trial will assess the effectiveness of medication review in reducing polypharmacy and DRPs. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT05820945 (March 21, 2023). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-026-07045-1.