Impact of a Novel Cost-Saving Pharmacy Program on Pregabalin Use and Health Care Costs.

Abstract

Pharmacy cost-saving programs often aim to reduce costs for members and payers by encouraging use of lower-tier or generic medications and lower-cost sales channels. In 2010, a national U.S. health plan began a novel pharmacy program directed at reducing pharmacy expenditures for targeted medications, including pregabalin. The program provided multiple options to avoid higher cost sharing: use mail order pharmacy or switch to a lower-cost alternative medication via mail order or retail. Members who did not choose any option eventually paid the full retail cost of pregabalin. To evaluate the impact of the pharmacy program on pregabalin and alternative medication use, health care costs, and health care utilization. This retrospective analysis of claims data included adult commercial health plan members with a retail claim for pregabalin in the first 13 months of the pharmacy program (identification [ID] period: February 1, 2010-February 28, 2011). Members whose benefit plan included the pharmacy program were assigned to the program cohort; all others were assigned to the nonprogram cohort. The program cohort index date was the first retail pregabalin claim during the ID period and after the program start; the nonprogram cohort index date was the first retail pregabalin claim during the ID period. All members were continuously enrolled for 12 months pre- and post-index and had at least 1 inpatient claim or ≥ 2 ambulatory visit claims for a pregabalin-indicated condition. Cohorts were propensity score matched (PSM) 1:1 with logistic regression on demographic and pre-index characteristics, including mail order and pregabalin use, comorbidity, health care costs, and health care utilization. Pregabalin, gabapentin and other alternative medication use, health care costs, and health care utilization were measured. The program cohort was also divided into 2 groups: members who changed to gabapentin post-index and those who did not. A difference-in-differences (DiD) analysis was used to compare the between-cohort change in pregabalin and alternative medication use patterns, health care costs, and health care resource utilization from pre- to post-index. The within-cohort change from pre- to post-index was analyzed by McNemar's test (categorical variables) or paired t-test (continuous variables). The Rao-Scott chi-square test (categorical) and general estimating equations (continuous) were used to analyze between-cohort differences at each time point. Differences in program member characteristics of those who changed versus those who did not change to gabapentin post-index were assessed by traditional chi-square test (categorical) or two-sample t-test (continuous variables). A total of 1,218 members in each cohort were PSM. Mean age was 51 years, 76.7% were women, and the most common pregabalin-indicated condition was fibromyalgia (77.6%). After the program start, the mean number of pregabalin claims from mail order and retail combined decreased in the program cohort from 4.7 pre-index to 3.8 post-index, and increased in the nonprogram cohort from 4.7 pre-index to 6.2 post-index (DiD, P < 0.001). Pregabalin mail order use increased from 3.1% to 48.1% of program members versus 2.8% to 9.4% of nonprogram members (DiD, P < 0.001). Program members were also more likely to change to the anticonvulsant gabapentin post-index than were nonprogram members (31.0% vs. 15.9%, P < 0.001). Mean total health care costs were similar between cohorts, and the pre- to post-index change did not differ between cohorts (DiD, P = 0.474). However, mean total pharmacy costs rose from pre-index to post-index by $820 and $790 in the program and nonprogram cohorts, respectively (both P < 0.001); the increase was similar between cohorts (DiD, P = 0.888). Program members who changed to gabapentin had a higher mean comorbidity score (P = 0.001) and greater post-index use of opioids, alternative medications, and health care resources (P < 0.050) than program members who did not change to gabapentin. The pharmacy program increased mail order use of pregabalin but reduced pregabalin claims from any venue. Program members were more likely to change to gabapentin than were nonprogram members, and those who changed had higher comorbidity, use of alternative medication, and health care resources. Despite increased mail order use for pregabalin and greater change to gabapentin by program members, the pharmacy program was not cost saving with respect to mean pharmacy or total health care costs.