Skipping antibiotic after hospital discharge leads to higher medical costs

Patients who skip filling an antibiotic prescription after hospital discharge because of high out-of-pocket costs are at increased risk of rehospitalization and cost the healthcare system substantially more in the long term, according to a study published in the October issue of the American Journal of Managed Care.

Margaret K. Pasquale, PhD, principal researcher, Comprehensive Health Insights, Louisville, KY, and colleagues conducted a retrospective analysis of all Medicare members from Humana’s SAS database who had a prescription claim for oral linezolid after an inpatient stay for skin and soft tissue infection or pneumonia from June 1, 2007 through April 30, 2011. Members were identified as filling the prescription or as a reversal (not filling the prescription within 3 days of discharge).

Each member who was classified as a claim reversal where compared with members who filled their prescriptions in terms of copays or coinsurance, out-of-pocket costs, infection-related and all-cause rehospitalization, and healthcare costs in the 30 days after hospital discharge.

“Linezolid, available in both oral and intravenous forms, has received high marks for its ability to treat difficult infections, including ventilator-acquired pneumonia and skin and soft-tissue infections,” according to a press statement. “Controlling these infections is a challenge hospitals face in keeping down medical costs, and linezolid is a preferred option because it can be given intravenously while the patient is hospitalized, and then in a pill upon discharge.”

In this study, more than 1,000 Medicare patients had received linezolid and 16.5% reversed a prescription for oral linezolid. Of the patients who filled their prescriptions, a higher percentage had low-income subsidy/dual-eligibility compared to those who had a claim reversal for the antibiotic. Also, a higher percentage of those who filled their oral linezolid prescriptions had been hospitalized with pneumonia.

As out-of-pocket costs increased, so did the number of patients who had a claim reversal. The mean out-of-pocket costs for members with a copay were $7.05, yet for those who had to pay coinsurance, the mean out-of-pocket cost was $466.52.

“Among members who reversed their prescription for oral linezolid, 73% filled a prescription for an alternative antibiotic during the 30 days after discharge,” Pasquale and colleagues noted.

“Infection-related rehospitalizations were 14 percentage points higher and all-cause rehospitalizations were 10 percentage points higher in the reversal group versus the fill group,” the researchers wrote.

Rehospitalizations drove up the costs for Medicare patients who had a claim reversal as the mean post-discharge costs in this group was more than $1,200 higher than the Medicare patients who took the oral linezolid as prescribed.

“This study found coinsurance benefit design was linked to higher out-of-pocket costs,” the researchers said. “If economic factors did indeed influence the decision to fill or reverse the linezolid prescription, then strategies to reduce member out-of-pocket costs (eg, benefit design) for all health plan members could enable better member access, and in turn, reduce total healthcare costs.”