Roughly one out of every four seniors who experience heart failure wind up back in the hospital within 30 days, according to a new report.

Every year, approximately 23% of heart failure patients with Medicare return to the hospital within a month, according to researchers from Mount Sinai School of Medicine. Over the course of the three-year study, that rate did not significantly change, despite the increased focus on reducing hospital readmissions, according to lead researchers Joseph Ross, M.D., M.H.S. The average age of patients who participated in the study was 80 years old.

The researchers argue that one barrier to improved care is the fee-for-service payment system, which pays out more money for hospitalized patients than for preventive care measures. The report appears in the journal Circulation: Heart Failure, which is published by the American Heart Association.