Home assessment of adherence to long-term medication in the elderly

Drug nonadherence to long-term medication is a common and poorly understood problem in the elderly. A study was conducted to assess whether elderly patients would accept a research assistant conducting pill counts in their homes, and to examine how nonadherence was associated with patient variables.

A letter and a telephone follow-up call were used to identify eligible patients (aged 65 years and over, with two or more chronic diseases).

A total of 98 eligible patients were identified. Fifty-nine agreed to participate in the study. Of the 59 participants, 54.7% were nonadherent to their medication regimen. Nonadherence was defined as an overall mean level of compliance of less than 80%. Drug regimen nonadherence was associated with the inability to read medication labels (P less than .01), but not with impaired visual acuity, the number of prescribed medications, the type of medication container lid, depression, cognitive impairment, perceived health status, or the cost of medications. Frequency of drug administration affected patient adherence to the medication regimen. Mean adherence of patients to prescriptions for drugs to be taken once or twice daily was 72%, whereas drugs to be taken three or four times daily had a mean adherence rate of 54% (P less than .01).

Using the simple pill count method on home visits, rates of nonadherence to long-term medication were comparable to those found in studies using electronic pill-counting devices. Larger studies are needed to clarify how other variables, in addition to patient inability to read medication labels, are associated with noncompliance with medication regimens for chronic diseases in elderly patients.