The impact of cognitive function on medication management: three studies.

OBJECTIVE Medication nonadherence has been a persistent problem over the past three decades; forgetting and being distracted from regular routines are the barriers most frequently cited by patients. Prior research on cognitive function and medication adherence has yielded mixed results. DESIGN This report compares findings of three studies: All were longitudinal, two were randomized controlled intervention trials, and one was descriptive. Samples of adult patients taking once daily lipid-lowering medication, diabetic patients with comorbid conditions on complex regimens, and early stage breast cancer patients on hormonal therapy completed similar batteries of standardized, valid, neuropsychological tests at baseline. MAIN OUTCOME MEASURES Adherence to medication regimens, over time, was tracked with electronic event monitors. RESULTS Medication nonadherence was prevalent in all studies. Deficits in attention/mental flexibility and/or working memory predicted nonadherence in all studies; impaired executive function was related to poor adherence in one study. CONCLUSION These findings suggest that better mental efficiency may be the key to better medication adherence with any regimen, and that targeted cognitive functions, which can be easily and quickly assessed, may identify patients at risk of poor adherence regardless of diagnosis or regimen.