General findings

In 2008, one out of every ten hospital stays was for a potentially preventable condition; 3.9 percent of the 39.9 million inpatient discharges were for potentially preventable acute conditions and 6.2 percent were for potentially preventable chronic conditions (table 1).

Table 1

Potentially preventable hospitalizations for acute and chronic conditions and all other hospitalizations, 2008.

The majority of potentially preventable hospital stays were for patients ages 65 and older (2.4 million stays, 60 percent of all potentially preventable hospitalizations). Patients aged 45–64 accounted for 1.1 million potentially preventable stays (28 percent), and patients 18–44 accounted for the remainder (12 percent).

Potentially preventable conditions accounted for about 10 percent of all hospitalizations for both males and females. However, males were more likely than females to be hospitalized for a potentially preventable chronic condition (6.8 percent of male stays, 5.8 percent of female stays) while males were less likely to be hospitalized for a potentially preventable acute condition (3.6 percent of male stays, 4.0 percent of female stays).

Stays for potentially preventable hospitalizations by payer, 2008

Hospital stays paid for by Medicare were over three times more likely to be potentially preventable than were stays paid for by private insurance or Medicaid. Uninsured stays were nearly twice as likely to be potentially preventable as privately insured or Medicaid-covered stays (figure 1).

Figure 1

Medicare-covered stays and uninsured stays were more likely to be potentially preventable than stays for other payers in 2008. Source: AHRQ, Center for Delivery, Organization, and Markets, Healthcare Cost and Utilization Project, Nationwide Inpatient (more...)

Potentially preventable chronic conditions accounted for 10.1 percent of Medicare stays, while potentially preventable acute conditions accounted for 6.8 percent.

Roughly the same proportion of privately insured and Medicaid covered stays—one out of twenty—were potentially preventable. Chronic conditions accounted for slightly more preventable Medicaid stays (3.8 percent) than privately insured stays (3.3 percent) while acute conditions accounted for slightly fewer Medicaid stays (1.6 percent) than privately insured stays (2.1 percent).

Potentially preventable conditions accounted for about one in ten uninsured hospital stays. Among uninsured stays, 6.8 percent of all stays were for potentially preventable chronic conditions and 3.1 percent of all stays were for potentially preventable acute conditions.

Stays for potentially preventable hospitalizations by community income, 2008

Hospital stays for patients living in the poorest communities were more likely to be potentially preventable (11.7 percent potentially preventable) than were stays for patients living in the wealthiest communities (8.1 percent potentially preventable) (figure 2). In fact, across the four community income quartiles, as community income level increased, the share of potentially preventable hospital stays decreased.

Figure 2

Patients from the poorest communities were most likely to have potentially preventable hospital stays in 2008. Source: AHRQ, Center for Delivery, Organization, and Markets, Healthcare Cost and Utilization Project, Nationwide Inpatient Sample (NIS), (more...)

Potentially preventable stays for chronic conditions accounted for 7.5 percent of the hospitalizations among patients living in the poorest communities. In contrast, stays for these conditions accounted for only 4.8 percent of the hospitalizations among patients living in the wealthiest communities. Potentially preventable stays for acute conditions comprised 4.2 percent of hospitalizations among patients living in the poorest communities, a slightly larger portion than among patients living in the wealthiest communities (a 3.4 percent share).

Stays for potentially preventable hospitalizations by hospital location, 2008

Potentially preventable conditions accounted for 9.2 percent of stays in urban hospitals but 15.9 percent of stays in rural hospitals (figure 3). Potentially preventable stays for acute conditions made up 3.4 percent of all urban hospital stays and 7.0 percent of all rural hospital stays while potentially preventable stays for chronic conditions made up 5.8 percent of urban hospital stays and 8.9 percent of rural hospital stays.

Figure 3

Stays in rural hospitals were more likely to be potentially preventable than stays in urban hospitals in 2008. Source: AHRQ, Center for Delivery, Organization, and Markets, Healthcare Cost and Utilization Project, Nationwide Inpatient Sample (NIS), 2008 (more...)

Stays for potentially preventable hospitalizations by region, 2008

Hospitalizations in the West were less likely to be potentially preventable than were those in Northeast, Midwest, and South of the United States (figure 4). In the West, a total of 8.1 percent of all hospitalizations were potentially preventable: 4.8 percent of these stays were for chronic conditions and 3.3 percent were for acute conditions. In the Northeast, Midwest, and South, 10 percent of more of all hospital stays were potentially preventable.

Figure 4

Hospital stays in the western U.S. were the least likely to be potentially preventable in 2008. Source: AHRQ, Center for Delivery, Organization, and Markets, Healthcare Cost and Utilization Project, Nationwide Inpatient Sample (NIS), 2008 and AHRQ Quality (more...)

Types of hospitals included in HCUP

HCUP is based on data from community hospitals, defined as short-term, non-Federal, general, and other hospitals, excluding hospital units of other institutions (e.g., prisons). HCUP data include OB-GYN, ENT, orthopedic, cancer, pediatric, public, and academic medical hospitals. They exclude long-term care, rehabilitation, psychiatric, and alcoholism and chemical dependency hospitals, but these types of discharges are included if they are from community hospitals.

Unit of analysis

The unit of analysis is the hospital discharge (i.e., the hospital stay), not a person or patient. This means that a person who is admitted to the hospital multiple times in one year will be counted each time as a separate “discharge” from the hospital.

Prevention Quality Indicators

The Prevention Quality Indicators (PQIs) are part of a set of AHRQ Quality Indicators (QIs) developed initially by investigators at Stanford University and the University of California under a contract with AHRQ. The PQIs are a set of measures that can be used with hospital inpatient discharge data to identify quality of care for “ambulatory care-sensitive conditions.” These are conditions for which good outpatient care can potentially prevent the need for hospitalization or for which early intervention can prevent complications or more severe disease. PQI rates can also be affected by other factors, such as disease prevalence. In this report, only observed rates are used, not the risk-adjusted rates (i.e., for age and gender) which are used for area comparisons. The PQIs have been approved by the National Quality Forum and are maintained and updated by Batelle, Inc. under contract to AHRQ.

Further information on the AHRQ QIs, including documentation and free software downloads, is available at http://www.qualityindicators.ahrq.gov/index.htm. This website includes information on the new version of the PQIs, Version 3.2. It also includes information on the new Pediatric Quality Indicators (PedQIs, formerly referred to as PDIs), which include the hospital admission rate measures for pediatric asthma and pediatric gastroenteritis.

Median community-level income

Median community-level income is the median household income of the patient’s ZIP Code of residence. The cut-offs for the quartile designation is determined using ZIP Code demographic data obtained from Claritas. The income quartile is missing for homeless and foreign patients.

Payer

Payer is the expected primary payer for the hospital stay. To make coding uniform across all HCUP data sources, payer combines detailed categories into more general groups:

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Medicare includes fee-for-service and managed care Medicare patients.

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Medicaid includes fee-for-service and managed care Medicaid patients. Patients covered by the State Children’s Health Insurance Program (SCHIP) may be included here. Because most state data do not identify SCHIP patients specifically, it is not possible to present this information separately.

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Private insurance includes Blue Cross, commercial carriers, and private HMOs and PPOs.

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Other includes Workers’ Compensation, TRICARE/CHAMPUS, CHAMPVA, Title V, and other government programs.

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Uninsured includes an insurance status of “self-pay” and “no charge.”

When more than one payer is listed for a hospital discharge, the first-listed payer is used.

Urban-rural hospital location

Urban-rural location is one of six categories as defined by the National Center for Health Statistics:

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Large Central Metropolitan: Central counties of metropolitan areas with a population of 1 million or greater

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Large Fringe Metropolitan: Fringe counties of counties of metropolitan areas with a population of 1 million or greater

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Medium Metropolitan: Counties in metro area of 250,000–999,999 population

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Small Metropolitan: Counties in metro areas of 50,000–249,999 population

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Micropolitan: Micropolitan counties, i.e. a non-metropolitan county with an area of 10,000 or more population

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Non-core: Non-metropolitan and non-micropolitan counties

These six categories are aggregated into urban and rural classifications, where urban includes large central metropolitan, large fringe metropolitan, medium metropolitan, and small metropolitan areas and rural includes micropolitan and non-core areas.

Region

Region is one of the four regions defined by the U.S. Census Bureau:

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Northeast: Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, and Pennsylvania

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Midwest: Ohio, Indiana, Illinois, Michigan, Wisconsin, Minnesota, Iowa, Missouri, North Dakota, South Dakota, Nebraska, and Kansas

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South: Delaware, Maryland, District of Columbia, Virginia, West Virginia, North Carolina, South Carolina, Georgia, Florida, Kentucky, Tennessee, Alabama, Mississippi, Arkansas, Louisiana, Oklahoma, and Texas

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West: Montana, Idaho, Wyoming, Colorado, New Mexico, Arizona, Utah, Nevada, Washington, Oregon, California, Alaska, and Hawaii