Out-of-Pocket Costs and Prescription Reversals With Oral Linezolid

Objective: To determine the relationship between benefit design, out-of-pocket costs, and prescription reversals, and the impact of reversals on rehospitalizations and total healthcare costs among Medicare members prescribed oral linezolid. Study Design: Medicare members from a national health plan prescribed oral linezolid posthospitalization for skin and soft tissue infection (SSTI) or pneumonia were followed retrospectively. Methods: Members were identified by an oral linezolid prescription between June 1, 2007, and April 30, 2011, where the index event was a prescription fill or reversal less than 2 days before or 10 days after discharge. Associations between out-of-pocket costs and reversal, and between reversal and rehospitalization 30 days postindex, were compared for prescription fills versus reversals. A generalized linear model calculated adjusted total healthcare costs per member controlling for age, sex, geographic region, and clinical characteristics. Results: Reversal rates rose progressively from 2% for members with out-of-pocket costs of $0 to 27% for member with out-of-pocket costs higher than $100 (P < .0001). Infection-related rehospitalizations were 23% versus 9% for members with a prescription reversal versus a fill (P < .0001). While postdischarge prescription drug costs were $1228.78 lower (P < .0001), adjusted mean medical costs were $2061.69 higher (P = .0033) and total healthcare costs were $1280.93 higher (P = .0349) for reversal versus fill members. Conclusions: Higher out-of-pocket costs were associated with higher rates of reversal, and reversals were associated with higher rates of rehospitalization and adjusted total healthcare costs among Medicare members prescribed oral linezolid posthospitalization for SSTI or pneumonia.