Out-of-Pocket Medication Expense Affects Adherence More Than Reimbursement Timing

For patients with private drug insurance plans, out-of-pocket expenses, not the timing of patient reimbursements, have a greater affect on medication adherence, according to a Canadian study. The study is important because while it is well known that medication nonadherence is a significant problem among patients with chronic diseases, and that drug insurance plans affect adherence, there was little evidence about the impact of reimbursement timing on medication adherence.

The study, published in the Journal of Managed Care & Specialty Pharmacy by Francois Despres, BSc, and colleagues at the University of Montreal, compared adherence to prescribed medications in privately insured patients from Quebec, Canada, with different timing of patient reimbursement and levels of out-of-pocket expenses. Patients in this study were 18 to 64 years of age and were in the reMed database from 2008 to 2012, which stores information related to prescribed medications filled at community pharmacies for a sample of Quebec residents. Each had filled at least 1 prescription for a medication belonging to 1 of the 10 most prescribed drug classes for chronic disease.

Patient reimbursement times were immediate (at the point of service of the portion of the cost covered by the insurer) or deferred (patient pays 100% of the medication costs at the pharmacy and receives reimbursement at a later time). Out-of-pocket expenses (including the deductible and coinsurance) were categorized into 5 levels (null category and quartiles) and adherence measured with the proportion of days covered over 1 year among new users of the medication studied.

The researchers estimated the adjusted mean differences of proportion of days covered between groups. They found there was no difference in medication adherence between the immediate (1345 patients) and deferred (437 patients) patient reimbursement groups (difference, 0.0%). Patients with the highest patient out-of-pocket expenses were less adherent than those with the lowest patient out-of-pocket expenses (difference, -19.0%; 95% CI, -24.0 to -13.0). The researchers noted that patients with no out-of-pocket expenses were actually less adherent than those with low out-of-pocket expenses (difference, -9.0%; 95% CI, -15.0 to -2.0).

The researchers said the lack of a correlation between medication adherence and the timing of patient reimbursement may be explained by the relatively rapid reimbursement of expenses by insurance companies in Canada. They hypothesize that patients in the study with no out-of-pocket expenses at the point of service might be less adherent to their medication regimen because they place less value on their medications than do people who must pay even a small amount.

The study was funded by Pfizer Canada.