Person:

Graves, Amy

Background Prior authorization is a popular, but understudied, strategy for reducing medication costs. We evaluated the impact of a controversial prior authorization policy in Michigan Medicaid on antidepressant use and health outcomes among dual Medicaid and Medicare enrollees with a Social Security Disability Insurance designation of permanent disability.

Methods We linked Medicaid and Medicare (2000-2003) claims for dual enrollees in Michigan and a comparison state, Indiana. Using interrupted time-series and longitudinal data analysis, we estimated the impact of the policy on antidepressant medication use, treatment initiation, disruptions in therapy, and adverse health events among continuously enrolled (Michigan, n = 28 798; Indiana, n = 21 769) and newly treated (Michigan, n = 3671; Indiana, n = 2400) patients.

Results In Michigan, the proportion of patients starting nonpreferred agents declined from 53% prepolicy to 20% postpolicy. The prior authorization policy was associated with a small sustained decrease in therapy initiation overall (9 per 10 000 population; P = .007). We also observed a short-term increase in switching among established users of nonpreferred agents overall (risk ratio, 2.88; 95% confidence interval, 1.87-4.42) and among those with depression (2.04; 1.22-3.42). However, we found no evidence of increased disruptions in treatment or adverse events (ie, hospitalization, emergency department use) among newly treated patients.

Conclusions Prior authorization was associated with increased use of preferred agents with no evidence of disruptions in therapy or adverse health events among new users. However, unintended effects on treatment initiation and switching among patients already taking the drug were also observed, lending support to the state's previous decision to discontinue prior approval for antidepressants in 2003.

Context Cost-related medication nonadherence (CRN) has been a persistent problem for individuals who are elderly and disabled in the United States. The impact of Medicare prescription drug coverage (Part D) on CRN is unknown.

Objective To estimate changes in CRN and forgoing basic needs to pay for drugs following Part D implementation.

Design, Setting, and Participants In a population-level study design, changes in study outcomes between 2005 and 2006 before and after Medicare Part D implementation were compared with historical changes between 2004 and 2005. The community-dwelling sample of the nationally representative Medicare Current Beneficiary Survey (unweighted unique n = 24 234; response rate, 72.3%) was used, and logistic regression analyses were controlled for demographic characteristics, health status, and historical trends.

Main Outcome Measures Self-reports of CRN (skipping or reducing doses, not obtaining prescriptions) and spending less on basic needs to afford medicines.

Results The unadjusted, weighted prevalence of CRN was 15.2% in 2004, 14.1% in 2005, and 11.5% after Part D implementation in 2006. The prevalence of spending less on basic needs was 10.6% in 2004, 11.1% in 2005, and 7.6% in 2006. Adjusted analyses comparing 2006 with 2005 and controlling for historical changes (2005 vs 2004) demonstrated significant decreases in the odds of CRN (ratio of odds ratios [ORs], 0.85; 95% confidence interval [CI], 0.74-0.98; P = .03) and spending less on basic needs (ratio of ORs, 0.59; 95% CI, 0.48-0.72; P < .001). No significant changes in CRN were observed among beneficiaries with fair to poor health (ratio of ORs, 1.00; 95% CI, 0.82-1.21; P = .97), despite high baseline CRN prevalence for this group (22.2% in 2005) and significant decreases among beneficiaries with good to excellent health (ratio of ORs, 0.77; 95% CI, 0.63-0.95; P = .02). However, significant reductions in spending less on basic needs were observed in both groups (fair to poor health: ratio of ORs, 0.60; 95% CI, 0.47-0.75; P < .001; and good to excellent health: ratio of ORs, 0.57; 95% CI, 0.44-0.75; P < .001).

Conclusions In this survey population, there was evidence for a small but significant overall decrease in CRN and forgoing basic needs following Part D implementation. However, no net decrease in CRN after Part D was observed among the sickest beneficiaries, who continued to experience higher rates of CRN.