Medication adherence in healthy elders: small cognitive changes make a big difference.

OBJECTIVE This was a cross-sectional study of the ability of independently living healthy elders to follow a medication regimen. Participants were divided into a group with High Cognitive Function (HCF) or Low Cognitive Function (LCF) based on their scores on the ADAS-Cog. METHOD Thirty-eight participants aged 65 or older and living independently in the community followed a twice-daily vitamin C regimen for 5 weeks. Adherence was measured using an electronic 7-day pillbox. RESULTS The LCF group had significantly poorer total adherence than the HCF group (LCF: 63.9 +/- 11.2%, HCF: 86.8 +/- 4.3%, t( 36) = 2.57, p = .007), and there was a 4.1 relative risk of non-adherence in the LCF group as compared to the HCF group. DISCUSSION This study has important implications for the conduct of clinical drug trials, as it provides strong evidence that even very mild cognitive impairment in healthy elderly has a detrimental impact on medication adherence.