CMS reimbursement reform and the incidence of hospital-acquired pulmonary embolism or deep vein thrombosis

Abstract

Background: In October 2008, the Centers for Medicare & Medicaid Services (CMS) stopped reimbursing hospitals for the marginal cost of treating certain preventable hospital-acquired conditions.

Objective: This study evaluates whether CMS's refusal to pay for hospital-acquired pulmonary embolism (PE) or deep vein thrombosis (DVT) resulted in a lower incidence of these conditions.

Design: We employ difference-in-differences modeling using 2007-2009 data from the Nationwide Inpatient Sample, an all-payer database of inpatient discharges in the U.S. Discharges between 1 January 2007 and 30 September 2008 were considered "before payment reform;" discharges between 1 October 2008 and 31 December 2009 were considered "after payment reform." Hierarchical regression models were fit to account for clustering of observations within hospitals.

Participants: The "before payment reform" and "after payment reform" incidences of PE or DVT among 65-69-year-old Medicare recipients were compared with three different control groups of: a) 60-64-year-old non-Medicare patients; b) 65-69-year-old non-Medicare patients; and c) 65-69-year-old privately insured patients. Hospital reimbursements for the control groups were not affected by payment reform.

Intervention: CMS payment reform for hospital-based reimbursement of patients with hip and knee replacement surgeries.

Main measures: The outcome was the incidence proportion of hip and knee replacement surgery admissions that developed pulmonary embolism or deep vein thrombosis.

Key results: At baseline, pulmonary embolism or deep vein thrombosis were present in 0.81% of all hip or knee replacement surgeries for Medicare patients aged 65-69 years old. CMS payment reform resulted in a 35% lower incidence of hospital-acquired pulmonary embolism or deep vein thrombosis in these patients (p = 0.015). Results were robust to sensitivity analyses.

Conclusion: CMS's refusal to pay for hospital-acquired conditions resulted in a lower incidence of hospital-acquired pulmonary embolism or deep vein thrombosis after hip or knee replacement surgery. Payment reform had the desired direction of effect.

Figure 1.

Trend, by quarter and year, of adjusted incidence of pulmonary embolism or deep vein thrombosis, Medicare 65–69 and Non-Medicare 60–64.