Higher Copays for Multiple Sclerosis Medications Contribute to Poor Patient Compliance, Outcomes

A recent study featured in the American Journal of Pharmacy Benefits examines the role of patient out-of-pocket cost on adherence to disease-modifying therapies for multiple sclerosis.

A higher patient cost share ratio for multiple sclerosis (MS) medications is linked to a higher treatment abandonment rate, according to recent research published in the Specialty Pharmacy 2012 issue of the American Journal of Pharmacy Benefits (AJPB).

The impact of cost sharing in the MS category may be of particular interest to many of the players in specialty pharmacy, because recent research from Prime Therapeutics has shown that MS specialty drug costs are the fastest growing category within the total cost of care and that pharmacy costs for the condition now exceed all medical costs.

Although the researchers from Prime suggest that the best way to address the MS drug price inflation issues is through rebates, other payers handle drug price increases by shifting more of the cost to the consumer through higher copays or coinsurance. In the study from AJPB, researchers examined the effect of increased cost-sharing on the likelihood of receiving treatment with disease-modifying therapies (DMTs), as well as its impact on patient adherence and subsequent treatment outcomes.

Liisa Palmer, PhD, director of the Outcomes Research Group at Thomson Reuters, and colleagues compared 14,497 patients treated for MS with 10,200 untreated patients with the condition from the Truven Health Analytics MarketScan Commercial Database and Medicare Supplemental and Coordination of Benefits Database to assess the chance of receiving DMTs between these groups. Within the treated group, they also examined the probability that a patient would receive DMTs based on their cost-sharing cohort. Patients in the treated group were assigned to a low- or high-cost sharing cohort based on health plan level determinants and the cost of their medications compared with the median cost of DMTs, which was determined to be $29.00.

After a year of follow-up, the researchers concluded that higher copays decrease the chance that a patient will get DMTs altogether, and this higher cost-sharing model also fosters suboptimal treatment adherence for those who do actually receive disease-modifying agents. Compared with patients in the low cost-sharing plans, patients responsible for covering a larger portion of their drugs out-of-pocket were more likely to discontinue treatment; adherence for the high cost-sharing cohort was 13% lower than the low cost-sharing group.

The study relied on prescription claims, so patients who received treatments that were billed under the medical benefit during the post-period were excluded from analysis. Patients with mild forms of MS — some of whom may have elected not to receive DMT treatment given their cost and inconvenience — may not have been captured by their analysis, the researchers conceded. “Because diagnosis codes do not specify MS type, we were unable to directly assess treatment availability with respect to disease progression,” they wrote.

The researchers concluded that benefit plans with high cost-sharing burdens “negatively impact treatment initiation and/or adherence,” and may “increase the risk of relapse, health resource use, and disease progression” in patients with MS. The consequences of suboptimal treatment and undertreatment under the pharmacy benefit will be the subject of future studies, according to the authors.