Cycling Through Migraine Preventive Treatments: Implications for All-Cause Total Direct Costs and Disease-Specific Costs.

BACKGROUND: Migraine is a common and disabling neurological disease associated with substantial economic burden. Among patients with migraine, it is unknown if cost differences exist when preventive migraine medication (PMM) switches occur.
OBJECTIVE: To understand the cost burden and health care resource utilization of patients who discontinue or cycle through 1 (PMM1), 2 (PMM2), or ≥ 3 (PMM3) unique PMM drug classes over a 12-month period versus patients who adhere persistently to their initial PMM class.
METHODS: This retrospective observational study used the Truven Health Analytics MarketScan databases to identify adult patients with migraine initiating their first PMM class (antidepressants, antiepileptics, beta blockers, or neurotoxins) from 2011-2013 (index date = first PMM claim). Patients were required to have ≥ 2 outpatient (1 if inpatient) migraine diagnosis codes (ICD-9-CM 346.xx) from 1 year pre-index to 1 year post-index with ≥ 1 code occurring pre-index. Inclusion criteria also required 12 months of pre- and post-index continuous medical and prescription enrollment. All-cause and migraine-specific total direct costs (outpatient, inpatient, emergency department, and prescriptions), based on the 2014 Consumer Price Index, were estimated for each PMM versus a persistent subgroup during the 12-month post-index period. Propensity score bin bootstrapping, controlling for patient baseline characteristics, was used to adjust separate cost comparisons between each PMM subgroup and the persistent subgroup; bootstrap simulations yielded propensity score-adjusted P values.
RESULTS: The study population included 55,402 patients who received a PMM. The study population was mainly female (85%) with a mean age of 39.2 years and mean Charlson Comorbidity Index of 0.31. Antiepileptics were the most common drug class chosen at index across all subgroups; however, lower use of antiepileptics was observed in PMM2 and PMM3 subgroups, which were more likely to be prescribed either antidepressants or beta blockers at index. Mean all-cause total direct costs, including prescription costs, were significantly higher in PMM2 ($13,429) and PMM3 ($18,394) subgroups versus the persistent subgroup ($11,941; each adjusted pairwise comparison, P < 0.001). Mean migraine-specific total direct costs were significantly lower for the persistent subgroup ($2,420) versus PMM2 and PMM3 subgroups and escalated with increasing numbers of drug class discontinuations or switches, from a mean of $2,997 to $5,004 (both adjusted pairwise comparisons, P < 0.001). Subgroup differences in all-cause and migraine-specific direct costs were primarily due to variations in outpatient and emergency department services.
CONCLUSIONS: All-cause total direct costs rose with increasing number of PMM switches over the 12-month post-index period, and were significantly higher than in the persistent subgroup, with the exception of PMM1. Additional analyses indicated that the lack of increase between PMM-persistent and PMM1 costs was due to higher pharmacy costs that were likely related to continuous use of medication in the PMM-persistent subgroup. These data suggest an increased cost burden among patients with migraine who cycle through ≥ 2 PMMs versus those who continue to receive their initial medication class. DISCLOSURES: Eli Lilly and Company was the sole sponsor and funder for this study and was responsible for the study design, data collection, data analysis, interpretation of data, and decision to publish the findings. All authors are employees and minor stockholders of Eli Lilly and Company. Nyhuis was employed by Eli Lilly and Company at the time of this study. The findings of this study were presented in part at the 18th Congress of the International Headache Society; September 7-10, 2017; Vancouver, Canada.