Approximately 23 percent of the population (about 62 million persons) had a medical condition in 1997 that resulted from an injury (Table 1), and approximately 70 percent of those people (about 43 million) had some medical expense for that condition. About 16 percent of children under age 16 had at least one injury-related condition, compared to about one quarter of people 16 years of age and over. People ages 16-24 were less likely to have an expense associated with an injury-related condition than those under 16 or 45 and over.

Females (21.2 percent) were less likely than males (25.0 percent) to have had an injury-related condition. Males and females who had an injury-related condition were equally likely to have a related medical expense. Whites (25.4 percent) were more likely than blacks (17.3 percent), Hispanics (17.5 percent), and others (14.6 percent) to have an injury-related condition. The probability of having an injury-related condition did not vary by either insurance status or poverty status. However, the uninsured population under age 65 were the least likely to report an injury-related expense.

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Total Expenses for Injury-Related Conditions

An estimated $57.9 billion was spent on injury-related conditions for the U.S. civilian noninstitutionalized population in 1997 (Table 2). This was 10.8 percent of all health care spending during that year. For people with an injury-related expense, the mean expense for injury-related conditions was $1,330 but the median expense was only $241.

As a proportion of total expenses for all health care in 1997, injuries presented a greater burden for people ages 16-24 (25.6 percent) than for those under 16 or 45 and over. The mean expense for injury-related conditions was lowest for children under age 16 ($467).

An estimated $35.3 billion was spent on health care for injury-related conditions for males, higher than the $22.6 billion spent for women. The proportion of total expenses associated with injuries was about twice as high for males (14.9 percent) as for females (7.5 percent). Per capita expenses were about 62 percent higher for males ($266) than for females ($163), and mean expenses for people with injury-related conditions also were higher for males ($1,536) than for females ($1,101). Per capita injury-related expenses for whites were $246 in 1997, higher than for blacks ($122) or Hispanics ($137).

Among those under age 65, the proportion of total medical expenses attributable to injuries was approximately twice as high for the uninsured (24.3 percent) as for people with private coverage (12.4 percent) and people with public insurance (11.0 percent). There were no statistically significant differences among poverty status groups in the proportion of total expenses attributable to injuries, per capita expenses, or the mean or median expenses for injury-related conditions.

Figures 1 and 2 summarize the distribution of expenses for injury- and non-injury-related conditions, respectively, by type of care received. Ambulatory care accounted for a higher proportion of expenditures for injuries (51.3 percent) than non injury conditions (31.7 percent). The proportion of total expenses that went for inpatient hospital care was similar for injury- and non injury- related conditions (36.9 percent and 39.3 percent, respectively). Dental care and prescribed medicines made up a smaller proportion of expenses for injury-related conditions: dental care, 2.2 vs. 9.0 percent; prescribed medicines, 4.4 vs. 14.6 percent.

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Ambulatory Care Expenses

In 1997 expenses for injury-related care received by the U.S. civilian noninstitutionalized population in office-based settings and clinics, hospital outpatient departments, emergency rooms, and clinics owned and operated by hospitals amounted to approximately $29.7 billion, representing 16.4 percent of the ambulatory care expenses for all conditions (Table 3). The per capita expense for ambulatory care for injury-related conditions was $109. For those with an injury-related expense, the mean cost of ambulatory care for injury-related conditions was $787 and the median expense was $234. Injury-related expenses for ambulatory visits accounted for about one-quarter of all ambulatory expenses for people ages 16-24 (26.4 percent) and 25-44 (24.5 percent), a higher proportion than for the other age groups. Per capita expenses for ambulatory care were highest for people ages 25-44 ($146) and 45- 64 ($152). For persons with injury-related expenses, mean injury-related ambulatory care expenses also were highest for people ages 25-44 ($968) and 45-64 ($991).

Expenses for injury-related ambulatory care were higher for males ($17.0 billion) than for females ($12.7 billion). The proportion of total ambulatory care expenses associated with injuries was about 9 percentage points higher for males than for females (21.6 vs. 12.3 percent). However, differences in mean ambulatory care expenses for males and females were not statistically significant.

There were no statistically significant differences in the proportion of total ambulatory expenses associated with injuries by race/ethnicity. The mean injury-related expense was not statistically significantly different for blacks ($689) than for either whites or Hispanics, but it was significantly higher for whites ($813) than for Hispanics ($594).

For the population under 65 years old, the proportion of total ambulatory expenses attributed to injuries was higher for uninsured people (29.7 percent) than for those with private insurance (19.3 percent) or public insurance (16.1 percent). Differences in mean expenses by insurance status for this age group were not statistically significant. For people age 65 and over, the proportion of total ambulatory care expenses attributed to injuries was more than twice as high for those covered by Medicare only (9.5 percent) as for people covered by Medicare and other public insurance (4.3 percent).

There were no statistically significant differences in mean ambulatory care expenses for injury-related conditions by poverty status.

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Inpatient Hospital Expenses

The inpatient expense estimates shown in Table 4 include room and board charges, all hospital diagnostic and laboratory expenses associated with the basic facility charge, payments for separately billed physician inpatient services, and emergency room expenses incurred immediately prior to inpatient stays for injury-related conditions. Estimated expenses for inpatient services for injury-related conditions in 1997 were about $21.4 billion, which constituted 10.2 percent of expenditures for all inpatient care. The mean inpatient expense per person for people with an injury-related inpatient expense was $9,510, while the median expense was $5,473.

The amount spent on injury-related conditions for people ages 16-24 ($4.6 billion) amounted to an estimated 39.6 percent of all inpatient expenses for that age group.¹ This proportion is substantially higher than the estimated proportions of total inpatient expenses for any other age group (ranging from 6.7 to 12.5 percent).

Males incurred about 72 percent of the total expenses for injury-related inpatient care in 1997— $15.3 billion, compared to only $6.1 billion for females. The proportion of inpatient expenses spent on injury-related care was approximately three times as high for males (15.4 percent) as for females (5.5 percent). Per capita expenses for injury-related inpatient care were nearly three times as high for males ($115) as for females ($44). The mean injury-related expense for those with an injury-related inpatient expense was about $4,300 higher for males than for females ($11,194 compared to $6,891).

The proportion of total inpatient expenses for injury-related care did not vary by race/ethnicity. However, per capita expenses for injury-related inpatient care for the white population ($93) were more than double expenses for the black population ($42), and the mean cost for inpatient care for injury-related conditions was substantially higher for whites than for blacks ($10,084 vs. $5,936).

There were no statistically significant differences in either the proportion of inpatient medical expenses attributable to injuries or the mean inpatient care expenses for injury-related conditions by either insurance status or poverty status.

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¹ Relative standard errors of 30 percent or more.

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Source of Payment

Figures 3 and 4 summarize the percent distribution of expenses by source of payment for injury- and non injury- related conditions in 1997. Workers’ Compensation covered 14.4 percent of injury-related expenses. The proportion paid out of pocket was smaller for injury-related conditions than for non-injury-related conditions (11.5 percent vs. 19.1 percent). In contrast, the proportion of expenses paid by private insurance was similar for both injuries (45.2 percent) and noninjuries (44.0 percent), despite the noteworthy proportion of expenses for injuries paid by Workers’ Compensation.

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Summary

Approximately $57.9 billion was spent on injury-related care in 1997, constituting 10.8 percent of all health care spending during that year. This amount does not include payments for over-the-counter-drugs, alternative care services, telephone contacts with medical providers, or expenses for durable medical equipment or other miscellaneous items such as eyeglasses or ambulance services.

The average total expense for injury-related conditions was lowest for children under 16 ($467 per person with expense). However, as a proportion of total health care expenditures in 1997, injuries imposed a relatively high burden on people ages 16-24 years; about one-quarter of their total health care costs were attributed to injury-related conditions, a significantly higher share than for most other age groups. Furthermore, injury-related health care for this age group accounted for about 40 percent of all inpatient care expenses (about $4.6 billion),² higher than for any other age group. Injury prevention strategies targeted toward this group of older teenagers and young adults may well be cost effective.

The proportion of total medical expenses associated with injuries was about twice as high for males (14.9 percent) as for females (7.5 percent). Males also incurred approximately 72 percent of all inpatient health care expenses for injury-related conditions ($15.3 billion). About 15.4 percent of all inpatient expenses for males were for injury-related conditions, approximately three times the proportion for females (5.5 percent). Injury-related conditions also accounted for approximately one-fifth (21.6 percent) of ambulatory care expenses for males compared to only 12.3 percent for females.

The impact of injuries on national health care expenditures raises important public policy issues. The extent of expenses for injury-related care is particularly significant when one considers that, unlike many major conditions, injuries often can be prevented or avoided by relatively inexpensive intervention programs (Bernstein and Schur, 1990). In Healthy People 2010 (Department of Health and Human Services (U.S.), 2000), the reduction of unintentional injuries, as well as violence and abuse, was identified as a priority area. Achievement of these national goals requires timely and accurate measures of the incidence of injury and expenses, including data on cause of injury and type of injury sustained, to form the basis for planning, analysis, and evaluation of injury control efforts (Miller and Lestine, 1996).

Workers' Compensation paid for about 14 percent of injury-related expenses in 1997.

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² Relative standard errors of 30 percent or more.

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References

Bernstein AB, Schur CL. Expenditures for unintentional injuries among the elderly. J Aging Health 1990; 2:157- 78.

Cohen JW, Krauss NA. Spending and service use among people with the fifteen most costly medical conditions, 1997. Health Aff 2003 Mar./Apr.; 22(2):129-38.

Cohen SB. Sample design of the 1996 Medical Expenditure Panel Survey Household Component. Rockville (MD): Agency for Health Care Policy and Research; 1997. MEPS Methodology Report No. 2. AHCPR Pub. No. 97-0027.

Cohen SB. Sample design of the 1997 Medical Expenditure Panel Survey Household Component. Rockville (MD): Agency for Healthcare Research and Quality; 2000. MEPS Methodology Report No.11. AHRQ Pub. No. 01-0001.

Department of Health and Human Services (U.S.). Healthy People 2010. 2nd ed. With Understanding and Improving Health and Objectives for Improving Health. 2 vols. Washington: U.S. Government Printing Office; Nov. 2000.

Hoyert DL, Arias E, Smith BL, et al. Deaths: final data for 1999. Hyattsville (MD): National Center for Health Statistics; 2001. National Vital Statistics Reports; Vol. 49, No. 8.

Miller TR, Lestine DC. Patterns of U.S. medical expenditures and utilization for injury, 1987. Am J Public Health 1996; 86:89-93.

Thorpe JM, Machlin SR. Health care expenses in the U.S. civilian noninstitutionalized population, 1997. Rockville (MD): Agency for Healthcare Research and Quality; 2000. AHRQ Pub. No. 01-R086.

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Figures

Figure 1. Percent distribution of expenses for injury-related conditions, by type of care: United States, 1997	Figure 2. Percent distribution of expenses for non-injury-related conditions, by type of care: United States, 1997
Figure 1. Percent distribution of expenses for injury-related conditions, by type of care: United States, 1997 Ambulatory 51.3% Inpatient 36.9% Prescribed medicines 4.4% Dental 2.2% Home health 5.2%	Figure 2. Percent distribution of expenses for non-injury-related conditions, by type of care: United States, 1997 Ambulatory 31.7% Inpatient 39.3% Prescribed medicines 1464% Dental 9.0% Home health 5.52%

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Tables

Table 1. Injury-related conditions and expenses—Percent of population with conditions and percent of those incurring expenses: United States, 1997

^aPercent of those with injury-related condition(s) who incurred some expense for their condition(s) during 1997.

^bUninsured refers to persons uninsured during the entire year. Public and private health insurance categories refer to individuals with public or private insurance at any time during the period. Individuals with both public and private insurance and those with CHAMPUS or CHAMPVA (Armed-Forces-related coverage) are classified as having private insurance.

^cPoor refers to incomes at or below the Federal poverty line; near-poor, over the poverty line through 125 percent of the poverty line; low income, over 125 percent through 200 percent of the poverty line; middle income, over 200 percent to 400 percent of the poverty line; and high income, over 400 percent of the poverty line.

Note: Restricted to civilian noninstitutionalized population.

Source: Center for Financing, Access, and Cost Trends, Agency for Healthcare Research and Quality: Medical Expenditure Panel Survey, 1997.

Table 2. Total medical expenses^a for injury-related conditions: United States, 1997

^aTotal medical expenses include inpatient hospital and physician services, ambulatory physician and nonphysician services, and prescribed medicines purchased during the year. Expenses for over-the-counter medications, alternative care services, and telephone contacts are not included. Expenses for durable medical equipment and other miscellaneous items are excluded because it was not possible to determine which of those expenses were associated with injuries.

^bNumerator is total expenses for injuries. Denominator is total medical expenses for both injury- and non-injury-related conditions.

^cUninsured refers to persons uninsured during the entire year. Public and private health insurance categories refer to individuals with public or private insurance at any time during the period. Individuals with both public and private insurance and those with CHAMPUS or CHAMPVA (Armed-Forces-related coverage) are classified as having private insurance.

^dPoor refers to family incomes at or below the Federal poverty line; near-poor, over the poverty line through 125 percent of the poverty line; low income, over 125 percent through 200 percent of the poverty line; middle income, over 200 percent to 400 percent of the poverty line; and high income, over 400 percent of the poverty line.

*Relative standard error equal to or greater than 30 percent.

Note: Restricted to civilian noninstitutionalized population.

Source: Center for Financing, Access, and Cost Trends, Agency for Healthcare Research and Quality: Medical Expenditure Panel Survey, 1997.

Table 3. Ambulatory medical expenses^a for injury-related conditions: United States, 1997

^aExpenses for visits to medical providers seen in office-based settings or clinics, hospital outpatient departments, emergency rooms (except visits resulting in an overnight hospital stay), and clinics owned and operated by hospitals, as well as expenses for events reported as hospital admissions without an overnight stay, are included.

^bNumerator is ambulatory expenses for injuries. Denominator is total ambulatory expenses for both injury- and non-injury-related conditions.

^cUninsured refers to persons uninsured during the entire year. Public and private health insurance categories refer to individuals with public or private insurance at any time during the period. Individuals with both public and private insurance and those with CHAMPUS or CHAMPVA (Armed-Forces-related coverage) are classified as having private insurance.

^dPoor refers to family incomes at or below the Federal poverty line; near-poor, over the poverty line through 125 percent of the poverty line; low income, over 125 percent through 200 percent of the poverty line; middle income, over 200 percent to 400 percent of the poverty line; and high income, over 400 percent of the poverty line.

*Relative standard error equal to or greater than 30 percent.

Note: Restricted to civilian noninstitutionalized population.

Source: Center for Financing, Access, and Cost Trends, Agency for Healthcare Research and Quality: Medical Expenditure Panel Survey, 1997.

Table 4. Inpatient medical expenses^a for injury-related conditions: United States, 1997

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Technical Appendix

Data in this report are based on the combined samples for the second year of the 1996 panel of the Medical Expenditure Panel Survey Household Component (MEPS HC) and the first year of the 1997 MEPS HC. MEPS is cosponsored by the Agency for Healthcare Research and Quality (AHRQ) and the National Center for Health Statistics (NCHS). The focus of the MEPS HC is to collect detailed data on demographic characteristics, health conditions, health status, use of medical care services, charges and payments for those services, access to care, health insurance coverage, income, and employment of the U.S. civilian noninstitutionalized population. In other components of MEPS, data are collected on the use, charges, and payments reported by providers (Medical Provider Component) and the supply side of the insurance market (Insurance Component).

The sample for the 1996 MEPS HC was selected from respondents to the 1995 National Health Interview Survey (NHIS), and the sample for the 1997 MEPS HC was selected from the 1996 NHIS. NHIS, which is conducted by NCHS, provides a nationally representative sample of the U.S. civilian noninstitutionalized population and reflects an oversampling of Hispanics and blacks.

The MEPS HC collects data through an overlapping panel design. In this design, data are collected through a precontact interview that is followed by a series of five rounds of interviews over a period of 21/2 years. Interviews are conducted with one member of each family, who reports on the health care experiences of the entire family. Two calendar years of medical expenditure and utilization data are collected in each household and captured using computer-assisted personal interviewing (CAPI). This series of data collection rounds is launched again each subsequent year on a new sample of households to provide overlapping samples of survey data that will provide continuous and current estimates of health care expenditures.

The estimates of total expenditures in Tables 1-4 are based on 32,636 sample persons. They are weighted to develop population estimates for a total of 271,278,585 persons who were in the U.S. civilian noninstitutionalized population for part or all of 1997. For persons who were in the target population for the full year, all expenditures from January 1 through December 31, 1997, were included in the estimates. People with part-year information include newborns, people who died during the year, and people who resided in an institution, were in the military, or lived outside the country for part of the year. Expenditures for deceased persons were measured for the period from January 1 through the date of death, while those for newborns were measured from the date of birth through December 31. Expenses incurred during periods of full-time active-duty military service, institutionalization, or residency outside the country were not included.

This report provides estimates of expenditures in 1997 for the treatment of conditions that were reported to be attributable to an injury. The estimates include expenditures for conditions associated with injuries that occurred in 1997 as well as in prior years. Expenditures refer to payments for health care services, including out-of- pocket payments and payments by private insurance, Medicaid, Medicare, Workers’ Compensation, and other sources. Ambulatory visits to medical providers in office and hospital settings, hospital inpatient care, home health care, and prescribed medicines are included in total expenditures, while payments for over-the-counter drugs, alternative care services, and telephone contacts with medical providers are not included. In contrast to other reports containing MEPS expenditure estimates, expenses for durable medical equipment and other miscellaneous items (eyeglasses, contact lenses, ambulance services, orthopedic items, hearing devices, prostheses, bathroom aids, medical equipment, disposable supplies, and other miscellaneous items or services) are also excluded because it was not possible to determine from the survey questions which of these expenses were associated with injuries.

The estimates were developed using information collected in the conditions and medical events sections of the MEPS questionnaire (www.meps.ahrq.gov/survey_comp/survey.jsp). In the conditions section, respondents were asked to identify medical conditions that bothered sample persons during the period covered by the interview and identify conditions that were due to an injury. In the medical events sections, which collect information about ambulatory visits, inpatient hospitalizations, dental care, home health care, and prescribed medicines, respondents were asked to identify the conditions that were associated with each reported medical event. This information was used to link medical events to associated injury-related conditions. Estimates of expenditures for these events were based on a combination of data obtained from sample persons’ medical providers in the MEPS Medical Provider Component (used as first priority where available), the medical events sections of the MEPS HC, and imputation procedures for missing data. For detailed information on the MEPS sample design for Panel 1, see Cohen (1997). For detailed information on the MEPS sample design for Panel 2, see Cohen (2000). For information on response rates and estimation procedures see the Documentation File for HC-020 (http://www.meps.ahrq.gov/data_stats/download_data/pufs/h20/h20doc.pdf).

In the report, expenses are shown by selected population characteristics, including age, sex, race/ethnicity, health insurance status, and poverty status. (Definitions of these terms are given below.) In addition to total expenses by these characteristics, estimates on per capita expenses and spending for persons with expenses are provided. The per capita estimates were computed as the total injury-related expenses for a particular group divided by the total population of that group. The average number of conditions per injury episode was 1.04, indicating that the overwhelming majority of injuries were associated with only one condition. The standard errors for the estimates in this report are shown in Tables A-F.

Definitions of Terms

Type of Service

The types of service shown in Figures 1 and 2 are:

• Hospital inpatient services - This category includes room and board and all hospital diagnostic and laboratory expenses associated with the basic facility charge, payments for separately billed physician inpatient services, and some emergency room expenses incurred immediately prior to inpatient stays. It excludes expenses for hospital discharges that did not involve an overnight stay, which are classified as ambulatory expenses.
   
• Ambulatory services - This category includes expenses for visits to medical providers seen in office-based settings or clinics, hospital outpatient departments, emergency rooms (except some visits resulting in an overnight hospital stay), and clinics owned and operated by hospitals. It also includes expenses for events reported as hospital admissions without an overnight stay.
   
• Prescribed medicines - This category includes expenses for all prescribed medications that were initially purchased or refilled during 1997, as well as expenses for diabetic supplies (some of which may have been purchased without a prescription).
   
• Dental services - This category covers expenses for any type of dental care provider, including general dentists, dental hygienists, dental technicians, dental surgeons, orthodontists, endodontists, and periodontists.
   
• Home health services - This category includes expenses for care provided by home health agencies and independent home health providers. Agency providers accounted for a large majority of the expenses in this category.

Source of Payment

The sources of payment shown in Figures 3 and 4 are classified as follows:

• Out-of-pocket - These are expenses paid by the user or other family member.
   
• Private insurance - This category includes payments made by insurance plans covering hospital and medical care (excluding payments from Medicare, Medicaid, and other public sources). Payments from Medigap plans or CHAMPUS and CHAMPVA (Armed-Forces-related coverage) are included. Payments from plans that provide coverage for a single service only, such as dental or vision coverage, are not included.
   
• Medicare—Medicare is a federally financed health insurance plan for the elderly, persons receiving Social Security disability payments, and most persons with end-stage renal disease. Medicare Part A, which provides hospital insurance, is automatically given to those who are eligible for Social Security. Medicare Part B provides supplementary medical insurance that pays for medical expenses and can be purchased for a monthly premium.
   
• Medicaid - Medicaid is a means-tested government program jointly financed by Federal and State funds that provides health care to those who are eligible. Program eligibility criteria vary significantly by State, but the program is designed to provide health coverage to families and individuals who are unable to afford necessary medical care.
   
• Workers' Compensation—Workers - Compensation is a system, required by law, of compensating workers injured or disabled in connection with work. This system establishes the liability of an employer for injuries or sickness that arise over and in the course of employment. The benefits under this system generally include hospital and other medical payments and compensation for loss of income.
   
• Other sources - This category includes payments from the Department of Veterans Affairs (except CHAMPVA); other Federal sources (Indian Health Service, military treatment facilities, and other care provided by the Federal Government); various State and local sources (community and neighborhood clinics, State and local health departments, and State programs other than Medicaid); various unclassified sources (e.g., automobile, homeowner’s, or other liability insurance, and other miscellaneous or unknown sources); Medicaid payments reported for people who were not reported as enrolled in the Medicaid program at any time during the year; and private insurance payments reported for people without any reported private health insurance coverage during the year.

Population Characteristics

Health Insurance Status

Individuals under age 65 were classified into the following three insurance categories.

• Any private health insurance—Individuals with insurance that provides coverage for hospital and physician care at any time during the year (other than Medicare, Medicaid, or other public hospital/physician coverage) are classified as having private insurance. Persons with Armed-Forces related coverage—CHAMPUS/CHAMPVA (currently called TRICARE)—are also included because the number of sample persons in this group is small and this type of coverage is similar to private insurance. Insurance that provides coverage for a single service only, such as dental or vision coverage, is not included. Public coverage only—Individuals are considered to have public coverage only if they met both of the following criteria:
  • They were not covered by private insurance at any time during the year.
  • They were covered by one of the following public programs at any point during the year: Medicare, Medicaid, or other public hospital/physician coverage.
• Uninsured—The uninsured are defined as persons not covered by Medicare, CHAMPUS/CHAMPVA, Medicaid, other public hospital/physician programs, or private hospital/physician insurance at any time during 1997. Individuals covered only by noncomprehensive State-specific programs (e.g., Maryland Kidney Disease Program, Colorado Child Health Plan) or private single-service plans (e.g., coverage for dental or vision care only, coverage for accidents or specific diseases) are not considered to be insured.

• Medicare only.
• Medicare and private insurance.
• Medicare and other public insurance.

Each person was classified according to the total 1997 income of his or her family. Within a household, all individuals related by blood, marriage, or adoption were considered to be a family. Personal income from all family members was summed to create family income. Possible sources of income included annual earnings from wages, salaries, bonuses, tips, and commissions; business and farm gains and losses; unemployment and Workers’ Compensation; interest and dividends; alimony, child support, and other private cash transfers; private pensions, individual retirement account (IRA) withdrawals, Social Security, and veterans’ payments; Supplemental Security Income and cash welfare payments from public assistance, Aid to Families with Dependent Children, and Aid to Dependent Children; gains or losses from estates, trusts, partnerships, S corporations, rent, and royalties; and a small amount of other income. Poverty status is the ratio of family income to the 1997 Federal poverty thresholds, which vary by family size and age of the head of the family. The categories are:

• Poor - This refers to persons in families with income at or less than the poverty line.
• Near-poor - This refers to persons in families with income over the poverty line through 125 percent of the poverty line.
• Low income - This category includes persons in families with incomes over 125 percent through 200 percent of the poverty line.
• Middle income - This category includes persons in families with income over 200 percent through 400 percent of the poverty line.
• High income - This category includes persons in families with income over 400 percent of the poverty line.

Significance Testing

Tests of statistical significance were used to determine whether the differences between populations exist at specified levels of confidence or whether they occurred by chance. Differences were tested using Z-scores having asymptotic normal properties at the 0.05 level of significance. However, each individual significance test was conducted at the 0.05 level, which does not control the overall Type I error level at 0.05.

Rounding

Estimates presented in the tables are rounded as follows:

• Percentages are rounded to the nearest 0.1 percentage point.
• Mean and median expenditures are rounded to the nearest dollar.
• Total expenditures are rounded to the nearest million dollar unit.

Some of the estimates for population totals of subgroups presented in the tables will not add exactly to the overall estimated population total as a consequence of rounding.

Table A. Standard errors for injury-related conditions and expenses—Percent of population with conditions and percent of those incurring expenses: United States, 1997

Corresponds to Table 1

^aPercent of those with injury-related condition(s) who incurred some expense for their condition(s) during 1997.

^bUninsured refers to persons uninsured during the entire year. Public and private health insurance categories refer to individuals with public or private insurance at any time during the period. Individuals with both public and private insurance and those with CHAMPUS or CHAMPVA (Armed-Forces-related coverage) are classified as having private insurance.

Note: Restricted to civilian noninstitutionalized population.

Source: Center for Financing, Access, and Cost Trends, Agency for Healthcare Research and Quality: Medical Expenditure Panel Survey, 1997.

Table B.  Standard errors for total medical expenses^a  for injury-related conditions: United States, 1997

Corresponds to Table 2

^aTotal medical expenses include inpatient hospital and physician services, ambulatory physician and nonphysician services, and prescribed medicines purchased during the year. Expenses for over-the-counter medications, alternative care services, and telephone contacts are not included. Expenses for durable medical equipment and other miscellaneous items are excluded because it was not possible to determine which of those expenses were associated with injuries.

^bNumerator is total expenses for injuries. Denominator is total medical expenses for both injury- and non-injury-related conditions.

^cUninsured refers to persons uninsured during the entire year. Public and private health insurance categories refer to individuals with public or private insurance at any time during the period. Individuals with both public and private insurance and those with CHAMPUS or CHAMPVA (Armed-Forces-related coverage) are classified as having private insurance.

^dPoor refers to family incomes at or below the Federal poverty line; near-poor, over the poverty line through 125 percent of the poverty line; low income, over 125 percent through 200 percent of the poverty line; middle income, over 200 percent to 400 percent of the poverty line; and high income, over 400 percent of the poverty line.

Source: Center for Financing, Access, and Cost Trends, Agency for Healthcare Research and Quality: Medical Expenditure Panel Survey, 1997.

Table C. Standard errors for ambulatory medical expenses^a for injury-related conditions: United States, 1997

Corresponds to Table 3

^aExpenses for visits to medical providers seen in office-based settings or clinics, hospital outpatient departments, emergency rooms (except visits resulting in an overnight hospital stay), and clinics owned and operated by hospitals, as well as expenses for events reported as hospital admissions without an overnight stay, are included.

^bNumerator is total expenses for injuries. Denominator is total medical expenses for both injury- and non-injury-related conditions.

^dPoor refers to family incomes at or below the Federal poverty line; near-poor, over the poverty line through 125 percent of the poverty line; low income, over 125 percent through 200 percent of the poverty line; middle income, over 200 percent to 400 percent of the poverty line; and high income, over 400 percent of the poverty line.

Note: Restricted to civilian noninstitutionalized population.

Source: Center for Financing, Access, and Cost Trends, Agency for Healthcare Research and Quality: Medical Expenditure Panel Survey, 1997.

Table D.  Standard errors for inpatient medical expenses^a for injury-related conditions, United States, 1997