User Support

May 2006

Anne Elixhauser, Ph.D. and C. Allison Russo. M.P.H.



Introduction

The number of uninsured in the United States is considerable, with about 48 million persons lacking health insurance.* While some use of healthcare services is discretionary, when faced with a serious or life-threatening condition, hospitalization may be the only option. The resulting health and financial burden of payment on the uninsured and the potential loss of revenues to hospitals can be substantial. In 2003, there were 1.7 million uninsured hospitalizations resulting in a national bill of $29 billion.

This Statistical Brief presents data from the Healthcare Cost and Utilization Project (HCUP) on uninsured hospital stays. Hospital utilization is described for those stays classified as uninsured because no third-party payer was identified. Comparisons are made between uninsured hospital stays and those covered by private insurance and Medicaid. All differences between estimates noted in the text are statistically significant at the 0.05 level or better.

Findings

Even though about 16.6 percent of the U.S. population was uninsured in 2003,* only 4.5 percent of hospital stays were uninsured. In 2003, 1.7 million uninsured hospitalizations resulted in a national bill of $29 billion.

General characteristics of uninsured hospital stays

Table 1 displays the characteristics of uninsured hospital stays compared with stays covered by private insurance, Medicaid, and all hospitalized patients. Although 18—44 year olds comprise 26.3 percent of hospital stays overall, a little over half of hospital patients who were uninsured are in this age range, compared with about one-third of privately insured patients and those covered by Medicaid. Overall, males account for 40.6 percent of U.S. hospital stays, but they make up 51.6 percent of uninsured stays.

The mean length of stay for uninsured hospitalizations was significantly shorter than for Medicaid—3.8 days, compared with 4.6 for Medicaid—and was almost identical to the length of stay for privately insured stays (3.7 days). Mean charges for uninsured, privately insured, and Medicaid-covered stays were virtually identical.

Admission source and discharge status for uninsured stays

As shown in figure 1, nearly 60 percent of hospital stays for the uninsured originated in the emergency department—nearly double the percentage for privately insured patients and 50 percent more than for stays billed to Medicaid.

Figure 2 depicts discharge status for uninsured hospital stays compared with stays billed to Medicaid and private payers. Only 2.2 percent of uninsured stays ended in discharge to home healthcare, as compared with 4.9 percent for the privately insured and 5.2 percent of Medicaid stays. (The overall value of 7.3 percent includes patients covered by Medicare.) About 3.5 percent of uninsured hospital stays ended in discharge against medical advice, which was nearly three times higher than for Medicaid and seven times higher than for stays billed to private insurers.

Differences in uninsured hospital stays, by region

Relative to the populations in each region, there were significant differences in the number of uninsured hospital stays within each region (table 2). In 2003, 38.1 percent of all hospital stays occurred in the South; however, the South accounted for nearly half of all uninsured hospitalizations. Some of this discrepancy can be accounted for by the higher percentage of the population in the South that is uninsured (19.8 percent), as compared with the Northeast (11.6 percent) and the Midwest (13.8 percent). However, the West has a comparable percentage of population that is uninsured (19.2 percent), and it accounts for 19.1 percent of all hospital stays—yet only 13.2 percent of all uninsured stays occur in the West. The Northeast and Midwest each accounted for about 19 percent of uninsured hospital stays.

Because populations vary by region, table 2 also presents the hospitalization rate per 10,000 people in each region. This table demonstrates that although the overall hospitalization rate was relatively similar in the Northeast, Midwest, and South (about 1,400 hospital stays per 10,000 people in each region), hospitalizations in the South were more likely to be uninsured. There were 81.2 uninsured hospitalizations per 10,000 people in the South, a figure 35 percent higher than the Northeast, 65 percent higher than the Midwest, and 137 percent higher than the West. The West had the lowest overall rate of hospitalizations, with just under 1,100 hospital stays per 10,000, and only 34.2 uninsured hospitalizations per 10,000 people.

Data Source

The estimates in this Statistical Brief are based upon data from the HCUP 2003 Nationwide Inpatient Sample (NIS).

Data on regional population estimates were obtained from Table 8: Annual Estimates of the Population for the United States, Regions, and Divisions: April 1, 2000 to July 1, 2005 (NST-EST2005-08), Population Division, U.S. Census Bureau, release date: December 22, 2005. https://www.census.gov/programs-surveys/popest/data/data-sets.html.

Data on the uninsured for 2003 were obtained from Rhoades, J. A. The Uninsured in America, 2003: Estimates for the U.S. Population under Age 65. Statistical Brief #41. June 2004. Agency for Healthcare Research and Quality, Rockville, MD. http://www.meps.ahrq.gov/mepsweb/data_files/publications/st41/stat41.pdf.

Data on the uninsured by region were obtained from Compendium Table 1. Health Insurance Coverage of the Civilian Institutionalized Population: Percent by Type of Coverage and Selected Population Characteristics, United States, First Half of 2004. Center for Financing, Access, and Cost Trends, Agency for Healthcare Research and Quality: Medical Expenditure Panel Survey Household Component, 2004. http://www.meps.ahrq.gov/mepsweb/.

Definitions

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.

Region

Region is one of the four regions defined by the U.S. Census Bureau:
— Northeast: Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, and Pennsylvania.
— Midwest: Ohio, Indiana, Illinois, Michigan, Wisconsin, Minnesota, Iowa, Missouri, North Dakota, South Dakota, Nebraska, and Kansas.
— South: Delaware, Maryland, District of Columbia, Virginia, West Virginia, North Carolina, South Carolina, Georgia, Florida, Kentucky, Tennessee, Alabama, Mississippi, Arkansas, Louisiana, Oklahoma, and Texas.
— West: Montana, Idaho, Wyoming, Colorado, New Mexico, Arizona, Utah, Nevada, Washington, Oregon, California, Alaska, and Hawaii.

Charges

Charges represent what the hospital billed for the case. Hospital charges reflect the amount the hospital charged for the entire hospital stay and do not include professional (MD) fees. For the purposes of this Statistical Brief, charges are rounded to the nearest hundred dollars.

Payer

Up to two payers can be coded for a hospital stay in HCUP data. When this occurs, the following hierarchy was used:
— If either payer is listed as Medicaid, payer is “Medicaid.”
— For non-Medicaid stays, if either payer is listed as Medicare, payer is “Medicare.”
— For stays that are neither Medicaid nor Medicare, if either payer is listed as private insurance, payer is “private insurance.”
— For stays that are not Medicaid, Medicare or private insurance, if either payer is some other third party payer, payer is “other,” which consists of Worker’s Compe