Medication Regimen Complexity and Adherence in Patients at Risk of Medication Misadventure

Abstract

Background: Dosage forms, dosing frequencies and additional instructions contribute to regimen complexity, which in turn is known to influence treatment outcomes. Aim: To evaluate the relationship between complexity of medication regimens and adherence in patients at risk of medication misadventure. Method: A modified Morisky scale was administered to inpatients during their hospital stay. Complexity of the medication regimens at the time of hospital discharge was assessed using the Medication Regimen Complexity Index. Results: The 310 subjects had a mean age of 72 years and were using a mean of 10.4 prescribed medications. High adherence was self-reported by 198 (64%) patients. Unintentional nonadherent behaviour was evident in 80 (26%) patients, while 51 (17%) patients admitted making intentional deviations from the recommended treatment. The reliability of the Morisky scale was poor (α = 0.38; 0.26-0.49). Patients who stopped taking their medicine when feeling worse had significantly less complex (p = 0.01) 'additional instructions' (median 4; 1-12) than those who did not stop their medicines (median 6; 0-18). This association was independent of age, gender and other medication regimen features. There were no significant differences between medication regimen features of patients who were forgetful, careful, and who stopped their medications when feeling better and their respective counterparts. Conclusion: Patients using medications with less complex additional instructions were more likely to stop taking their medicine when feeling worse. Interventions designed to improve adherence by reducing regimen complexity are unlikely to be effective in all patients, especially in those with intentional nonadherence. J Pharm Pract Res 2006; 36: 99-102.

Clinical Outcomes Associated with Medication Regimen Complexity in Older People: A Systematic Review

“…Table S1 lists the characteristics of the included studies. Countries of origin were the United States (n = 7), Australia (n = 4), Canada (n = 2), Sweden (n = 2), and Israel (n = 1) …”

“…Medication data were sourced from medical records (7 studies); a combination of medical records and medications brought to a clinical examination (2 studies); medication histories taken by pharmacists during home visits (1 study); medical records and pharmacist home medication reviews (1 study); an administrative database (1 study); hospital records and medication containers (1 study); or participant report or hospital medical records, primary care physician records, and telephone calls to the participant's pharmacy (1 study), or the data source was not defined (2 studies) …”

“…Of the six studies investigating adherence, four assessed self‐reported medication adherence. The four‐item Morisky scale was used in three studies . In one study, self‐reported adherence was assessed as the proportion of medications taken correctly divided by all medications.…”

Patient‐Centered Care for Older Adults with Multiple Chronic Conditions: A Stepwise Approach from the American Geriatrics Society

“…The more complex a treatment regimen, the higher the risk of nonadherence, adverse reactions, poorer quality of life, greater economic burden, and greater strain and depression in caregivers . Medication adherence also changes according to situational factors and perceptions of need, cost, or current symptoms …”

Patient-centered care for people living with multimorbidity

“…Increasing regimen complexity is associated with a higher likelihood of non-adherence, adverse events, economic burden and declines in quality of life for patients, and with greater strain and depression in caregivers [52,84–88]. Clinical feasibility and patient preferences should inform treatment decisions.…”