The Effects of Medicare Advantage Contract Concentration on Patients' Nursing Home Outcomes.

OBJECTIVE: The Medicare Modernization Act of 2004 allowed Medicare Advantage (MA) contracts to form provider networks in order to concentrate their patients among preferred providers. We focus on the skilled nursing facility (SNF) industry to assess patients' health when treating SNFs concentrate more patients from the same MA contract.

DATA SOURCES/STUDY SETTING: We use Medicare Beneficiary Summary File and Health, HEDIS, and the Minimum Data Set for patient attributes and OSCAR, LTCfocus.org, and Nursing Home Compare for SNF attributes. We include 1,069,436 MA enrollees newly admitted to SNF between 2012 and 2014.

STUDY DESIGN: Using a MA contract fixed-effect model, we examine the effect of prevalence of a patient's MA contract in the treating SNF on patient's health outcomes including 180-day survival, 30-day hospital readmission, 30-day home discharge, and nursing home length of stay. We use an Instrumental Variable (IV), the expected share of admissions in a SNF from patient's MA contract calculated using a McFadden choice model.

PRINCIPAL FINDINGS: We find no relationship between SNF contract concentration and patients' outcomes after applying the IV.

CONCLUSIONS: While MA plans appear to steer patients to specific SNFs, we do not observe significant returns to patient outcomes related to concentration.