John Bian1, William H Dow, David B Matchar. 1. Division of Preventive Medicine, University of Alabama at Birmingham, Deep South Center on Effectiveness at Birmingham VA Medical Center, 35295-4410, USA. jbian@uab.edu
Abstract
OBJECTIVE: To examine associations between Medicare health maintenance organization (HMO) penetration and stroke mortality outcomes among older persons. STUDY DESIGN: Panel analysis of nationally representative secondary data from 1993 to 1998. METHODS: The first analysis sample included ischemic stroke hospitalizations among older persons in the Nationwide Inpatient Sample; the second included county-level ischemic stroke deaths in the National Vital Statistics System. The 2 samples were merged with the HMO enrollment data and the 2001 Area Resource File. The 2 outcomes were in hospital death status and county-level population ischemic stroke death rates among older persons; the 2 utilization variables were length of hospital stay for ischemic stroke and proportion of ischemic stroke deaths occurring in hospitals. The 3 key explanatory variables were county-level Medicare total, independent practice association, and nonindependent practice association HMO penetration. Ordinary least squares analysis with hospital or county fixed effects was used in estimation. RESULTS: Medicare HMO penetration was not associated with the 2 ischemic stroke mortality outcomes (P > .05). Increases in Medicare total and independent practice association HMO penetration were associated with a significant shift in a higher proportion of stroke deaths from hospitals to nursing homes or residences (P < .05). Medicare HMO penetration was negatively associated with length of stay, although this was not statistically significant (P > .05). CONCLUSIONS: Increased Medicare HMO penetration was associated with a shift in ischemic stroke deaths from hospitals to nonhospital settings. The effect of Medicare HMO penetration on quality of stroke care needs further research.
OBJECTIVE: To examine associations between Medicare health maintenance organization (HMO) penetration and stroke mortality outcomes among older persons. STUDY DESIGN: Panel analysis of nationally representative secondary data from 1993 to 1998. METHODS: The first analysis sample included ischemic stroke hospitalizations among older persons in the Nationwide Inpatient Sample; the second included county-level ischemic stroke deaths in the National Vital Statistics System. The 2 samples were merged with the HMO enrollment data and the 2001 Area Resource File. The 2 outcomes were in hospital death status and county-level population ischemic stroke death rates among older persons; the 2 utilization variables were length of hospital stay for ischemic stroke and proportion of ischemic stroke deaths occurring in hospitals. The 3 key explanatory variables were county-level Medicare total, independent practice association, and nonindependent practice association HMO penetration. Ordinary least squares analysis with hospital or county fixed effects was used in estimation. RESULTS: Medicare HMO penetration was not associated with the 2 ischemic stroke mortality outcomes (P > .05). Increases in Medicare total and independent practice association HMO penetration were associated with a significant shift in a higher proportion of stroke deaths from hospitals to nursing homes or residences (P < .05). Medicare HMO penetration was negatively associated with length of stay, although this was not statistically significant (P > .05). CONCLUSIONS: Increased Medicare HMO penetration was associated with a shift in ischemic stroke deaths from hospitals to nonhospital settings. The effect of Medicare HMO penetration on quality of stroke care needs further research.