Medication regimen complexity and adherence among older adults.

Two studies were conducted to examine the relationship between medication regimen complexity and adherence among older adults recently discharged from hospitals (N = 178) and those not recently hospitalized (N = 98). Medication regimen complexity was measured by the Medication Complexity Index (Kelley, 1988), which measures the number, frequency, and types of actions required to enact a medication regimen. Adherence to the regimen was measured by pill count and verbal self-report. The negative correlations between regimen complexity and adherence were in the predicted direction but did not achieve statistical significance. Medication regimen complexity may have a larger impact on aspects of medication management other than adherence to the prescriptive regimen.