Variations in Quality Outcomes Among Hospitals in Different Types of Health Systems, 1995 - 2000
Askar Chukmaitov, M.D., M.P.A.
Virginia Commonwealth University
Gloria J. Bazzoli, Ph.D.
Virginia Commonwealth University
Agency For Healthcare Research and Quality, Grant #R01 HS13094
Rationale for the Study
Forces to reduce costs and improve quality of care motivated hospitals to join health systems in the 1990s
Bazzoli et al. (2000) have found differences in costs and financial performance across hospital system types Did not examine hospitals’ quality performance across different types of hospital systems Important issue given concerns regarding safety and quality 44,000 to 98,000 hospital deaths in the US each year caused by medical errors (IOM, 1999)
Methods
Design Longitudinal analysis of 1995-2000 data Data: AHA, HCUP (SID) 1995-2000 Sampling All nonfederal, short-term, general medicalsurgical hospitals from 11 states (AZ, CA, CO, FL, IA, MD, MA, NJ, NY, WA, and WI)
Analytic Approach Adjusted Least Square Means (ALSM) calculated for each IQI and PSI: Patient age, gender, acuity, and case-mix
Key Variables
Hospitals in Different Types of Health Systems:
Centralized Health System (CHS), Centralized Physician/Insurance Health System, Moderately Centralized Health System (MCHS), Decentralized Health System (DHS), Independent Hospital System (IndHS) (Bazzoli et al. 1999)
Patient Outcomes:
IQIs are measures of mortality rates for specific diagnosis; IQIs selected for study: AMI, CHF, Stroke, GI hemorrhage, and Pneumonia PSIs are adverse events or complications that occur during care; Selected PSIs: complications of anesthesia, death in low mortality DRGs, decubitus ulcer, infections due to medical care, post-op hemorrhage, post-op PE and DVT, sepsis, and accidental puncture and laceration
Description of Various Types of Health Systems
Centralized Health System (CHS) Centralized Physician/ Insurance Health System (CPIHS) Moderately Decentralized Centralized Health System Health System (DHS) (MCHS) Independent Hospital System (IndHS)
high degree of centralization in hospital services, physician arrangements, and insurance products
high levels of centralization for physician arrangements and insurance products at the health system level; hospital services not highly centralized
moderate levels of centralization for all service/product dimensions
high levels of decentralization in hospital services, physician arrangements, and insurance products at the hospital level
little differentiation of: hospital services, physician arrangements, and insurance products
(Bazzoli et al. 1999)
Trends in Health Systems in 1995 – 2000
2000
9.0%
2.7%
41.7%
41.1%
2.3%
Years
1998
6.6% 1.3%
35.3% 47.7% 6.6%
1995
5.3%
13.9%
26.7%
50.5%
3.7%
0%
10%
20%
30%
40%
50% Percent of Systems
60%
70%
80%
90%
100%
Centralized Health System Decentralized Health System
Centralized Physician/Insurance System Moderately Centralized Health System Independent Health System
Results for Different System Types
IQI mortality rates for AMI, CHF, Stroke, GI hemorrhage, and Pneumonia:
The best performers – hospitals in DHS, CHS, and CPIHS in the 1995 – 2000 period Significantly better than hospitals in other system types PSI adverse event rates:
Less clear and less significant trends for the best or the worse performers However, hospitals in more centralized health systems tend to perform worse than hospitals in other system types for a number of PSIs
Results Results for Different System Types Results
ALSM for IQI 17 - Stroke Mortality Rate
0.25
0.23
0.21
0.19
Rates
0.17
0.15
0.13
0.11
0.09 1995 1998 Years 2000
Independent Hospital System Centralized Physician/Insurance Health System Decentralized Health System
Centralized Health System Moderately Centralized Health System
Results for Different System Types
ALSM for PSI 03 - Decubitus Ulcer Adverse Event Rate
0.024
0.022
0.02
Rates
0.018
0.016
0.014
0.012 1995 1998 Years 2000
Independent Hospital System Centralized Physician/Insurance Health System Decentralized Health System
Centralized Health System Moderately Centralized Health System
Results for IQI and PSI Indicators Over Time
Increase in IQI mortality rates outcomes after 1998, except AMI
Leveling or increase in PSI adverse events after 1998
Results for IQI and PSI Indicators Over Time
0.13
ALSM for IQI 18 - GI Hemorrhage Mortality Rate
0.12
0.11
0.1
Rates
0.09
0.08
0.07
0.06
0.05 1995 1998 Years 2000
Independent Hospital System Centralized Physician/Insurance Health System Decentralized Health System
Centralized Health System Moderately Centralized Health System
Results for IQI and PSI Indicators Over Time
ALSM for PSI 12 - Post-operative PE or DVT Complication Rate
0.021
0.019
0.017
0.015
Rates
0.013
0.011
0.009
0.007
0.005 1995 1998 Years 2000
Independent Hospital System Centralized Physician/Insurance System Decentralized Health System
Centralized Health System Moderately Centralized Health System
Significance to Policy
Hospitals in more centralized health systems and in Decentralized Health Systems have better IQIs than hospitals in other systems. This relationship holds over time.
Hospitals in more centralized health systems tend to perform worse in terms of PSI, even though differences are not always significant.
Future research needs to examine the organizational characteristics and internal processes adopted by different systems that lead to higher quality of care as measured by IQI and PSI performance.
Performance on many indicators declined after 1998 – suggestive of BBA effect.
Future research needs to look for potential adverse quality effects from BBA or potentially other market/policy factors.