SUMMARY OBJECTIVE: This study aimed to assess older people’s knowledge of the purpose of drugs prescribed at medical appointments in primary care units and the possible factors related to their level of knowledge about their medications. METHODS: This was a cross-sectional study conducted in 22 basic health units in Brazil. Patients aged ≥60 years were included in this study (n=674). Knowledge of prescribed medications was assessed by comparing the responses to the questionnaire and the medication and prescription information. Multivariate analyses were conducted using the Poisson regression with robust variance. RESULTS: The mean age of the sample was 70.1 (standard deviation: ±7.1) years. Among 674 patients, 272 (40.4%) did not know the indication of at least 1 of their prescribed drugs; among them, 78 (11.6%) did not know the indication of any of their prescribed drugs. In the final multivariate analysis, polypharmacy, illiteracy, and cognitive impairment were found to be associated with misunderstanding the purpose of at least one prescribed drug. Moreover, illiteracy and cognitive impairment were associated with a greater misunderstanding of the purpose of all prescribed drugs. CONCLUSIONS: In the studied sample, patients demonstrated a high rate of misunderstanding of the purpose of prescribed drugs. Therefore, it is necessary for health services and professionals to implement strategies that increase the quality of the guidance and instructions given to older people in order to promote adherence to treatment.

ABSTRACT BACKGROUND: Physician and patient-related characteristics can influence prescription of medications to older patients within primary healthcare. Use of Brazilian criteria may indicate the real prevalence of prescription of potentially inappropriate medications to this population. OBJECTIVES: To evaluate prescription of potentially inappropriate medications to older patients within primary care and identify patient-related and prescribing physician-related factors. DESIGN AND SETTING: This cross-sectional study was conducted in 22 public primary care facilities in Brazil, among older people (≥ 60 years) who were waiting for medical consultations. METHODS: Interviews were conducted before and after the medical consultations. If the patient received a medical prescription at the consultation, all the drugs prescribed and the physician's medical council registration number were recorded. Prevalence ratios were estimated to ascertain the magnitude of prescription of potentially inappropriate medications, along with patient and physician-related factors associated with such prescription. RESULTS: In total, 417 older patients were included; 45.3% had received ≥ 1 potentially inappropriate medication, and 86.8% out of 53 physicians involved had prescribed ≥ 1 potentially inappropriate medication. The strongest patient-related factor associated with higher prevalence of prescription of potentially inappropriate medications was polypharmacy. Among physician-related factors, the number of patients attended, number of prescriptions and length of medical practice < 10 years were positively associated with prescription of potentially inappropriate medications. CONCLUSIONS: High prevalence of prescription of potentially inappropriate medications was observed. Physician-related characteristics can influence prescription of medications to older people within primary healthcare. This suggests that there is a need for interventions among all physicians, especially younger physicians.