Medication-related factors associated with health-related quality of life in patients older than 65 years with polypharmacy

In the current public health framework, the importance of medication as a determinant of citizens' health has emerged as a factor warranting special attention. Most studies investigating the relationship between medication and quality of life do so from the perspective of adherence. However, other medication-related factors identified at home visits may be associated with health-related quality of life. Methods and design Objective: To describe the relationship between medication-related factors and the healthrelated quality of life in patients older than 65 years who use multiple medications (polypharmacy). Design: Cross-sectional descriptive study. Setting: Primary care. Participants: Patients older than 65 years who use multiple medications (n = 375). Measurements: The main outcome measure was health-related quality of life according to the EuroQol-5D instrument. Sociodemographic, clinical and medication-related variables were recorded during home interviews. Results Mean age was 74.72 +/- 5.59 years, and 65.5% of our participants were women. The global level of health-related quality of life according to the EQ-5D visual analog scale was 59.25 +/- 20.92. Of the five EuroQol dimensions, anxiety/depression and pain were the most frequently reported, while mobility and self-care were the dimensions with the greatest impact on selfreported quality of life. Multivariate analysis indicated that functional independence was the factor most strongly associated (beta = 14.27 p < 0.001) with better health-related quality of life, while illiteracy (beta = -13.58 p < 0.001), depression (beta = -10.13 p < 0.001), social risk (beta = -7.23 p = 0.004) and using more than 10 medicines (beta = -4.85 p = 0.009) were strongly associated with a poorer health-related quality of life. Conclusions Factors inherent within the patient such as functional incapacity, cognitive impairment and social and emotional problems were the main constraints to quality of life in our study population. The number of medicines taken was negatively related with quality of life.