Factors associated with appropriate knowledge of the indications for prescribed drugs among community-dwelling older patients with polypharmacy.

BACKGROUND

polypharmacy contributes to patients' non-adherence with physicians' prescriptions. Patients' knowledge about the indications for their medicines is one of the factors influencing adherence.

OBJECTIVE

to identify factors associated with appropriate knowledge about the indications for drugs prescribed to older patients with polypharmacy.

METHODS

in a primary care setting, using home interviews and postal questionnaires, patients aged 60 and over who were taking five or more prescribed drugs simultaneously were asked about their medication. Multiple logistic regression analysis was used to evaluate the association (odds ratio, OR) between medication knowledge and explanatory variables like medication use, sex, age, living situation and educational level.

RESULTS

seven hundred and fifty-four participants (mean age 73.2 years) reported an average daily intake of nine (SD 3.0) prescribed drugs. Only 15% of the patients were able to recall the indication for each of their prescribed drugs. Variables that were negatively associated with correct reporting of all indications were taking many prescribed drugs (e.g. ≥10 versus ≤5: OR 0.05), age 80 years or over (versus 60-69 years: OR 0.47) and male sex (OR 0.53). Patients living with a partner were more knowledgeable than patients living alone (OR 2.11). We did not find an association with educational level.

CONCLUSION

among older patients using five or more prescribed drugs, there was little understanding of the indications for their drugs, especially among patients taking the highest number of drugs, patients aged 80 or over, and men. Patients living independently with a partner were more knowledgeable than others.