Objective: To determine whether elderly patients with complex drug regimens have enough information to ensure safe drug use.
Methods: A cross-sectional study was conducted in Spain based on interviews of a random sample of 265 patients aged over 65 and taking at least five drugs for multiple comorbidities. General practitioners reported on diagnoses, drugs, dosage and biochemical laboratory results. Patients were asked about the medications they were taking (with higher scores indicating greater knowledge).
Results: The patients took an average of 7.9 medications (SD 3.0). The mean scores were low for precautions (mean 0.3, SD 0.7) and how to properly store medications (mean 2.0, SD 3.0). Scores were significantly higher when physicians regularly provided patients with information (F-test 3.3, p = 0.039) and were not related to gender, years of treatment or health status. Frequent changes in medication adversely affected the scores (p = 0.03). Higher scores were related to a smaller number of medication errors (t-test 2.2, p = 0.032, CI 95% of the difference 0.6 - 1.2).
Conclusions: Older complex chronic patients are unaware of the precautions they must adopt to use their medications safely. Patient knowledge does contribute to reducing medication errors. When physicians change prescriptions, modify doses or introduce new medications, more information needs to be provided for safe use of the drugs.
Keywords: medication; patient medication knowledge; patient safety; patient–physician communication.