National Healthcare Disparities Report 2004

Methods Applying AHRQ Quality Indicators to Healthcare Cost and Utilization Project (HCUP) Data for the Second National Healthcare Disparities Report

By Rosanna Coffey, Ph.D., Marguerite Barrett, M.S., Bob Houchens, Ph.D., Ernest Moy, M.D., M.P.H., Roxanne Andrews, Ph.D., Ed Kelley, Ph.D., Denise Remus, Ph.D., R.N.

August 10, 2004

The Agency for Healthcare Research and Quality (AHRQ) Quality Indicators (QIs) were applied to the HCUP hospital discharge data for several measures in this report. The AHRQ QIs, originally developed by AHRQ staff (and termed the HCUP QIs), recently have been revised and improved by the University of California San Francisco and Stanford University (UCSF-Stanford) under contract with AHRQ. The QIs are measures of quality associated with processes of care that occurred in an outpatient or an inpatient setting. The QIs rely solely on hospital inpatient administrative data and, for this reason, are screens for examining quality that may indicate the need for more in-depth studies. The AHRQ QIs include three sets of measures:

Prevention Quality Indicators (PQIs)'or ambulatory care sensitive conditions'identify hospital admissions that evidence suggests could have been avoided, at least in part, through high-quality outpatient care (AHRQ, 2001; Davies et al., 2001).
Inpatient Quality Indicators (IQIs) reflect quality of care inside hospitals and include measures of utilization of procedures for which there are questions of overuse, underuse, or misuse (AHRQ, 2002; Davies et al., 2001).
Patient Safety Indicators (PSIs) reflect quality of care inside hospitals, by focusing on surgical complications and other iatrogenic events (AHRQ, 2003; McDonald et al., 2002).

The QI measures selected for this report are described in Table 1 at the end of this methods section.

The Healthcare Cost and Utilization Project (HCUP) is a family of healthcare databases and related software tools and products developed through a Federal-State-Industry partnership and sponsored by AHRQ. HCUP databases bring together the data collection efforts of State data organizations, hospital associations, private data organizations, and the Federal government to create a national information resource of discharge-level health care data. HCUP includes the largest collection of longitudinal hospital care data in the United States, with all-payer, encounter-level information beginning in 1988. These databases enable research on a broad range of health policy issues, including cost and quality of health services, medical practice patterns, access to health care programs, and outcomes of treatments at the national, State and local market levels.

The 2001 HCUP Statewide Inpatient Databases (SID), a census of hospitals (with all of their discharges), from 22 participating States were used to create a disparities analysis file designed to provide national estimates on disparities for this report. A sample of hospitals from the following States were included Arizona, California, Colorado, Connecticut, Florida, Georgia, Hawaii, Kansas, Maryland, Massachusetts, Michigan, Missouri, New Jersey, New York, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Virginia, Vermont, and Wisconsin. For the list of the HCUP data sources, see Table 2 at the end of this methods section.

To apply the AHRQ Quality Indicators to HCUP hospital discharge data, several steps were taken: 1) QI software review and modification, 2) acquisition of population-based data, 3) general preparation of HCUP data, 4) special methods for race/ethnicity reporting, and 4) identification of statistical methods. These steps, described briefly below, are presented in detail in the Technical Specifications for HCUP Measures in the Second National Healthcare Quality Report and the National Healthcare Disparities Report (Barrett, Houchens, Coffey, et al., 2004), available from AHRQ on request.