Hospitalizations for Injury: United States, 1996

by Margaret J. Hall, Ph.D., and Maria F. Owings, Ph.D., Division of Health Care Statistics

Abstract

Objectives—This report presents national estimates of the 1996 hospitalizations

for injury in the United States. Numbers and rates of discharges are shown within

sex, age, and racial groups by type of injury. Average lengths of stay and days of

care data by injury type are also included.

Methods—Estimates are based on medical abstract data collected in the

National Hospital Discharge Survey. Diagnoses are coded according to the

International Classification of Diseases, 9th Revision, Clinical Modification

(ICD–9–CM). Injuries are defined as ICD–9–CM codes 800–999. External causes of

injury are defined as codes E800–E999 (E-codes).

Results—In 1996, there were 2.6 million hospitalizations for injury. Fractures

resulted in over a million hospitalizations; medical injuries, including adverse effects

and complications, were responsible for 666,000 hospitalizations. The medical

records for 64 percent of the patients hospitalized for injuries had an external

cause-of-injury code (E-code). Elderly people had the largest number and rate of

injuries.

Conclusions—Data on injuries requiring hospitalization and characteristics of

patients differentially affected can be used to design and target more effective injury

prevention programs. Preventing injuries would decrease the considerable pain,

disability, and economic impact associated with these conditions.

Keywords: inpatients c injury c poisoning c external cause of injury codes (E-codes)

Introduction

Injuries cost the United States over

$200 billion in 1995 due to lost

productivity and medical care (1). This

was double the estimate for 1985 (2).

Care for and consequences of injuries

account for approximately 12 percent of

U.S. health care costs (3).

In addition to the monetary costs of

injury, there were serious human costs

in 1996. Close to 150,000 persons died

from injuries, which were the leading

cause of death for people younger than

45 years of age (4). Injury also resulted

in the hospitalization of approximately

2.6 million patients (table 1) who

remained in the hospital for a total of

13.8 million days. Injuries were one of

the leading reasons for hospital

admission for those under 45 years of

age (5).

Injuries serious enough to result in

hospitalization are particularly costly in

terms of human suffering, health care

resource consumption, and time lost

from work. Because a universal system

for reporting nonfatal injuries does not

exist, hospital discharge data are

valuable sources of information on these

injuries.

The primary purpose of this report

is to present National Hospital

Discharge Survey (NHDS) data on the

characteristics (i.e., sex, age, and race)

of patients hospitalized for particular

types of injuries and the duration of

their hospital stays. The data on trauma

and poisoning are useful to

epidemiologists and public health

Advance

Data

Number 318 + August 9, 2000

From Vital and Health Statistics of the CENTERS FOR DISEASE CONTROL AND PREVENTION/National Center for Health Statistics

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Center for Health Statistics CENTERS FOR DISEASE CONTROL

AND PREVENTION

Acknowledgments

This report was prepared in the Division of Health Care Statistics. This report was edited by Klaudia M. Cox and typeset by Annette F. Holman

of the Publications Branch, Division of Data Services.
officials who design and implement

injury surveillance, control, and

prevention programs. The data on

medical injuries are useful to hospitals,

other providers, and those in charge of

quality review and improvement

programs. Knowing the types of injuries

requiring hospitalization and the groups

who have disproportionately higher rates

of various injuries will enable health

care professionals to more efficiently

and effectively target their efforts to

prevent injuries.

Data are also presented on the

extent to which external causes of injury

(E-codes) were reported in the 1996

NHDS. Accurate and reliable

information about the cause of injuries

(e.g., motor vehicles, falls, gun shots,

medical misadventures, or recreational

activities) combined with diagnosis data

(e.g. fractures, burns, internal injuries) is

critical for helping public health and

medical care providers design more

suitable interventions to prevent future

injuries. NHDS data cannot currently be

used to analyze the incidence of injuries

in relation to their causes because

information on cause of injury is

incomplete, but it is improving. Between

1991 and 1996, the percent of first-listed

injury discharges in NHDS that had at

least one external cause recorded

increased from 44 (6) to 64 percent.

This report updates the information on

the number of states mandating E-code

collection.

Methods

Data source

NHDS has collected data since

1965 from a national probability sample

of hospital inpatient records for the

National Center for Health Statistics.

Hospitals with at least six beds, an

average length of stay of fewer than 30

days, and classified as general hospitals

or children’s general hospitals were

included in the survey. Federal, military,

and Department of Veterans Affairs

hospitals were excluded. For 1996, 480

hospitals participated in the survey,

which was a response rate of

94.7 percent. Data were collected for

approximately 282,000 discharges from

these hospitals.

Information gathered in NHDS

included age, sex, expected source of

payment, days of care, and discharge

status for each patient. For 78 percent of

the patients, race was also recorded.

NHDS also included data on the

hospitals’ ownership and their Census

regions. Medical information about

patients was also gathered. This

included up to seven diagnoses and up

to four surgical and nonsurgical

operations and procedures. Medical data

were coded according to the

International Classification of Diseases,

9th Revision, Clinical Modification

(ICD–9–CM) (7).

Injury patients were defined as

those with a principal or first-listed

diagnosis within ICD–9–CM codes

800–994, referred to as true injuries

(trauma and poisoning), or codes

995–999, referred to as medical injuries

(adverse effects and miscellaneous

complications of surgical and medical

care) (7,8). Information on the cause of

the injury should have been recorded in

the medical record (using E-codes)

along with the injury diagnosis. E-codes

were identified using ICD–9–CM codes

E800–E999.

Estimation

Sampled data from NHDS were

inflated to produce national estimates

using a multistage estimation procedure.

A description of the estimation

procedure, as well as other aspects of

the survey’s design, can be found in the

National Hospital Discharge Survey

Annual Summary for 1993 (9).

The standard error of a statistic is

primarily a measure of the sampling

variability that occurs by chance

because only a sample rather than the

entire universe is surveyed. Estimates of

sampling variability for this report were

calculated with SUDAAN (10).

Statistical significance

A determination of statistical

significance in this report was based on

the two-sided t-test with a critical value

of 1.96 (0.05 level of significance).

When an estimate is referred to as

higher or lower than another estimate,

this means that the difference is

statistically significant.

Results

Almost 2.6 million injuries required

hospitalization in 1996. This was an

overall rate of 96.6 per 10,000

population. Over 1 million of these

injuries were fractures—a rate of 38.3

per 10,000 population. Miscellaneous

complications of medical and surgical

care were the reason for 643,000

hospitalizations—a rate of 24.4 per

10,000 population. Although other types

of injuries were considerably less

frequent, there were more than 100,000

hospitalizations for the following

categories: poisoning and toxic effects,

intracranial injuries, lacerations and

open wounds, and sprains and strains

(table 1).

The following sections of this report

will compare the rates for different types

of injury within sex, race, and age

groups. This is followed by a

presentation of the same injury

categories by average lengths of stay

and days of care. The next section will

discuss E-code data availability for

various subgroups and types of injuries.

The paper concludes with an

interpretation of the major findings and

a discussion of policy implications.

Type of injury by sex

The overall rate of injury for males

and females did not differ significantly

(table 1), but there were significant

differences by sex in some specific

categories of injuries. Females had a

higher rate of fractures than males.

Females also had a higher rate of

poisoning and toxic effects, which

includes overdoses and ‘‘wrong

substance given or taken in error’’ (7).

The rates for intracranial injuries,

lacerations and open wounds,

dislocations, burns, internal injuries, and

other injuries (as defined in tables 1–4)

were higher for males than for females.

Type of injury by race

The overall rate of injury was

similar for white and black people

(table 1), but there were some

statistically significant differences

2 Advance Data No. 318 + August 9, 2000
between the two groups’ rates for

various types of injuries. White people

had a higher fracture rate than black

people. Blacks had higher rates of

lacerations and open wounds, burns,

internal injuries, and miscellaneous

complications of surgical and medical

care.

Type of injury by age

The rate of hospitalization per

10,000 population for injuries ranged

from 38.6 for children under 15 years of

age, to 288.7 for the elderly (65 years

and over). The rate for elderly persons

was significantly higher than the rate for

each of the other age groups studied

(table 2).

The fracture rate was lowest for the

under-15 years age group and highest

for the elderly age group. Fractures of

the bones of the arm or leg were

responsible for the majority of fracture

hospitalizations for those under age 65

years. For those under 15 years of age,

72 percent of the fractures fell into these

two categories: for the 15–44 year olds,

59 percent, and for the 45–64 year olds,

61 percent. For persons 65 years and

over, 60 percent of the fractures were

hip fractures.

In addition to their high fracture

rate, the elderly had higher rates of

intracranial injuries, superficial injuries

and contusions, and other injuries than

each of the other age groups studied.

The 15–24 year olds had higher

rates of intracranial injuries than each of

the other age groups under age 65 years,

and this group, along with the 25–34

year olds, had higher rates of lacerations

and open wounds than all of the other

age groups. The 15–24, 25–34, and

35–44 year old age groups had higher

poisoning rates than all of the other age

groups and lower rates of sprains and

strains than the older groups.

Beginning with the 25–34 age

group, the rate of miscellaneous

complications of surgical and medical

care increased significantly for each

successively higher age group. More

than half of the patients in the under 15

years, 45–64 years, and 65 years and

over age groups, and 44 percent of those

Table 1. Number and rate of patients discharged from short-stay hospitals by first-listed injury diagnoses, sex, and race: United States,

1996

[Discharges from non-Federal hospitals. Excludes newborn infants. Diagnostic groupings and code number inclusions are based on the International Classification of

Diseases, 9th Revision, Clinical Modification (ICD–9–CM)]

First-listed diagnosis and ICD–9–CM code

Sex Race1

Both

sexes Male Female White Black

All

other

Not

stated

Number of discharges in thousands

All injury and poisoning ......................... 800–999 2,550 1,277 1,273 1,664 293 109 484

Fractures.................................. 800–829 1,012 421 591 703 73 37 199

Dislocation................................. 830–839 23 14 9 14 *4 * *5

Sprains and strains ........................... 840–848 104 58 46 68 *7 * 27

Intracranial injuries (excluding those with skull fracture) ..... 850–854 141 91 50 85 18 8 29

Internal injury of chest, abdomen, and pelvis............ 860–869 82 59 23 47 15 6 14

Lacerations, open wounds, injuries to blood vessels ....... 870–904 131 101 30 77 28 9 17

Late effects of injuries and poisoning2 ................ 905–909 * * * * * * *

Superficial injuries and contusions .................. 910–924 61 31 30 36 9 *3 12

Burns .................................... 940–949 38 28 10 21 9 * *6

Other injury .......................... 925–939,950–959 55 32 23 34 6 * 13

Poisoning and toxic effects....................... 960–989 208 91 117 132 28 11 38

Other effects of environmental causes................ 990–994 17 11 *6 9 * * *

Certain adverse effects not elsewhere classified. . . . . . . . . . . . . 995 23 11 12 13 * * *6

Miscellaneous complications of surgical and medical care.... 996–999 643 323 320 418 89 26 110

Discharge rate per 10,000 population

All injury and poisoning ......................... 800–999 96.6 99.2 94.1 76.1 88.1 91.2 . . .

Fractures.................................. 800–829 38.3 32.7 43.7 32.2 21.8 30.8 . . .

Dislocation................................. 830–839 0.9 1.1 0.6 0.6 *1.2 * . . .

Sprains and strains ........................... 840–848 3.9 4.5 3.4 3.1 *2.1 * . . .

Intracranial injuries (excluding those with skull fracture) ..... 850–854 5.3 7.0 3.7 3.9 5.5 6.6 . . .

Internal injury of chest, abdomen, and pelvis............ 860–869 3.1 4.6 1.7 2.2 4.4 5.1 . . .

Lacerations, open wounds, injuries to blood vessels ....... 870–904 5.0 7.8 2.3 3.5 8.5 7.4 . . .

Late effects of injury and poisoning2 ................. 905–909 * * * * * * . . .

Superficial injuries and contusions .................. 910–924 2.3 2.4 2.2 1.7 2.7 *2.7 . . .

Burns .................................... 940–949 1.4 2.1 0.7 1.0 2.7 * . . .

Other injury .......................... 925–939,950–959 2.1 2.5 1.7 1.5 1.9 * . . .

Poisoning and toxic effects....................... 960–989 7.9 7.1 8.7 6.1 8.3 8.8 . . .

Other effects of environmental causes................ 990–994 0.6 0.8 *0.5 0.4 * * . . .

Certain adverse effects not elsewhere classified. . . . . . . . . . . . . 995 0.9 0.9 0.9 0.6 * * . . .

Miscellaneous complications of surgical and medical care.... 996–999 24.4 25.1 23.6 19.1 26.8 21.8 . . .

* Figure does not meet standard of reliability or precision.

. . . Category not applicable.

1Numbers and rates for race categories are based on the 78 percent of discharges with a specified race.

2This category should not be first-listed. Rather it supplements information on a principal diagnosis.

Advance Data No. 318 + August 9, 2000 3
aged 15–44 years with a diagnosis in

this category had complications of an

internal prosthetic device, implant, or

graft. Seventeen percent of the

miscellaneous complications category

who were 15–44 years of age,

16 percent of those aged 45–64, and

14 percent of the elderly patients had

postoperative infections.

Figure 1 presents data on the rate of

injury hospitalizations per 10,000

population for six age groups by sex.

Not only does this indicate the high

elderly rate for both sexes relative to the

younger age groups, but it also shows

the very high rate of hospitalizations for

elderly females. Figure 2 illustrates the

proportion of injuries in each of four

age groups that fall into the fractures

and miscellaneous complications of

medical and surgical care categories.

Fractures and miscellaneous

complications of medical and surgical

care rates for elderly patients far

exceeded those of the other age groups.

Days of care

The data on days of care in table 3

are included to provide information

about the share of hospital resources

being used for different categories of

patients with injuries. In addition, data

on the average length of stay can be

used as an indicator of the seriousness

of the condition. The average length of

stay for the different diagnostic

categories ranged from 2.7 days for

patients with sprains and strains to 7.8

days for burns (table 3). In addition to

the burns category, average lengths of

stay of 5 or more days occurred for

patients with fractures, intracranial

injuries, internal injuries, and

miscellaneous complications of surgical

and medical care.

E-codes

External causes of injury are

defined by ICD–9–CM codes E800–

E999.

Table 4 shows the percent of

patients with injuries who had at least

one E-code on their record by sex, age,

race, diagnoses for specific injuries, and

number of diagnoses. This percent is

also shown for hospital region,

ownership, and size.

In 1996, 1.6 million patients, or

64 percent of patients hospitalized due

to an injury, had at least one recorded

E-code. This percent was similar for

males and females. The percent of

E-code completion ranged from

54 percent of the 65–74 year olds to

Table 2. Number and rate of patients discharged from short-stay hospitals by first-listed injury diagnoses and age: United States, 1996

[Discharges from non-Federal hospitals. Excludes newborn infants. Diagnostic groupings and code number inclusions are based on the International Classification of

Diseases, 9th Revision, Clinical Modification (ICD–9–CM)]

First-listed diagnosis and ICD–9–CM code

All

ages

Under

15 years

15–24

years

25–34

years

35–44

years

45–64

years

65 years

and over

Number of discharges in thousands

All injury and poisoning . . . . . . . . . . . . . . . . . . . . . . . 800–999 2,550 223 270 265 330 485 977

Fractures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800–829 1,012 71 86 81 97 154 523

Dislocation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 830–839 23 * *6 *4 * *4 *4

Sprains and strains . . . . . . . . . . . . . . . . . . . . . . . . . 840–848 104 * *10 14 15 33 30

Intracranial injuries (excluding those with skull fracture) . . . 850–854 141 20 26 15 16 18 46

Internal injury of chest, abdomen, and pelvis. . . . . . . . . . 860–869 82 9 17 14 17 14 11

Lacerations, open wounds, injuries to blood vessels . . . . . 870–904 131 16 30 29 19 22 15

Late effects of injuries and poisoning1 . . . . . . . . . . . . . . 905–909 * * * * * * *

Superficial injuries and contusions . . . . . . . . . . . . . . . . 910–924 61 *7 *7 *6 *7 8 26

Burns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 940–949 38 11 *3 *6 *5 9 *4

Other injury . . . . . . . . . . . . . . . . . . . . . . . . 925–939,950–959 55 13 *6 7 7 7 15

Poisoning and toxic effects. . . . . . . . . . . . . . . . . . . . . 960–989 208 24 47 40 46 30 22

Other effects of environmental causes. . . . . . . . . . . . . . 990–994 17 * * * * * *

Certain adverse effects not elsewhere classified. . . . . . . . . . . 995 23 * * * * 7 7

Miscellaneous complications of surgical and medical care. . 996–999 643 41 30 45 87 174 266

Discharge rate per 10,000 population

All injury and poisoning . . . . . . . . . . . . . . . . . . . . . . . 800–999 96.6 38.6 75.6 66.4 76.5 90.3 288.7

Fractures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800–829 38.3 12.4 24.0 20.3 22.4 28.7 154.5

Dislocation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 830–839 0.9 * *1.5 *1.0 * *0.7 *1.1

Sprains and strains . . . . . . . . . . . . . . . . . . . . . . . . . 840–848 3.9 * *2.8 3.5 3.5 6.1 8.8

Intracranial injuries (excluding those with skull fracture) . . . 850–854 5.3 3.5 7.2 3.7 3.7 3.4 13.6

Internal injury of chest, abdomen, and pelvis. . . . . . . . . . 860–869 3.1 1.6 4.7 3.6 3.9 2.7 3.2

Lacerations, open wounds, injuries to blood vessels . . . . . 870–904 5.0 2.8 8.3 7.2 4.4 4.2 4.5

Late effects of injuries and poisoning1 . . . . . . . . . . . . . . 905–909 * * * * * * *

Superficial injuries and contusions . . . . . . . . . . . . . . . . 910–924 2.3 *1.3 *1.9 *1.6 *1.5 1.4 7.7

Burns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 940–949 1.4 1.9 *0.8 *1.6 *1.2 1.7 *1.1

Other injury . . . . . . . . . . . . . . . . . . . . . . . . 925–939,950–959 2.1 2.2 *1.6 1.7 1.7 1.3 4.6

Poisoning and toxic effects. . . . . . . . . . . . . . . . . . . . . 960–989 7.9 4.2 13.0 10.1 10.7 5.5 6.5

Other effects of environmental causes. . . . . . . . . . . . . . 990–994 0.6 0.6 0.8 0.3 0.9 0.2 1.3

Certain adverse effects not elsewhere classified. . . . . . . . . . . 995 0.9 0.6 0.4 0.3 0.5 1.4 2.2

Miscellaneous complications of surgical and medical care. . 996–999 24.4 7.2 8.3 11.4 20.1 32.4 78.4

* Figure does not meet standard of reliability or precision.

1This category should not be first-listed because it supplements information on a principal diagnosis.

4 Advance Data No. 318 + August 9, 2000
about three quarters of the 15–24 year

olds. Sixty-nine percent of the black

patients had at least one E-code in their

patient records compared with

63 percent of the white patients. In the

Northeast, over three-fourths of the

records had E-codes and in the West,

over two-thirds had these codes. In the

South and Midwest, E-codes were

recorded for at least half of the patients

hospitalized for injury or poisoning.

There was considerable variation

among the various types of injuries in

completion of E-codes. Only 47 percent

of the sprains and strains had an E-code

compared with about 90 percent of those

with poisoning and toxic effects. Other

categories with at least two-thirds

E-code completion were intracranial

injuries, lacerations and open wounds,

superficial injuries, burns, and other

effects of environmental causes.

Discussion

The human and economic costs of

injuries requiring hospitalization are

considerable. The data presented in this

report provide information about the

types of injuries requiring

hospitalization, the number of hospital

days devoted to their care, and the

groups who have disproportionately

higher rates of certain injuries. E-code

data from NHDS are incomplete and,

therefore, could not be used in the

interpretation of the data. However,

information was incorporated about the

cause of death for fatal injuries because

it is recorded on death certificates. It is

assumed that many of the causes that

resulted in a higher number of fatal

injuries within certain groups also

resulted in higher nonfatal injuries

requiring hospitalization for these same

groups.

NHDS data show that elderly

people had the highest hospitalization

rate for injuries. Over half a million of

the elderly patients’ injuries were

fractures (table 2). Baker and others (11)

indicate that advanced age substantially

increases the risk of hospitalization for

minor fractures. This may partially

explain the elderly population’s higher

hospitalization rate. But this age group

also had numerous serious fractures,

including almost 350,000 hip fractures

(5). The rates of intracranial injuries,

superficial injuries and contusions, and

other injuries were also significantly

higher for the elderly population.

Two-thirds of the elderly population’s

deaths due to injury resulted from motor

vehicle injuries, firearms, suffocation,

and falls (12). It is likely that a number

of the nonfatal injuries also were due to

these same causes.

Fractures were also numerous for

each of the other age groups, although

the rates were low relative to the elderly

population. Women had a higher rate of

fractures than men did, and white people

had a higher rate than black people did.

The higher fracture rate for women is

due to the very high rate for women

over 65 years of age (207.5 per 10,000

population). This rate was more than

double the rate of 78.2 for males in that

age group. One reason for the higher

female rate could be the higher number

Under 15

years

15-24

years

25-34

years

35-44

years

45-64

years

65 years

and over

Age

0

50

0

100

150

200

250

300

350

Rate per 10,000

Male Female

Figure 1. Rate of injury hospitalizations by age and sex: United States, 1996

38.6

72.9

90.3

288.7

Under 15

years

15-44

years

45-64

years

65 years

and over

Age

00 100 150 200 250 300 50

Rate per 10,000 hospitalizations for injury

Fractures Miscellaneous complications Other injuries

Figure 2. Rate of injury hospitalizations by age and selected diagnoses: United States,

1996

Advance Data No. 318 + August 9, 2000 5
of women who suffer from osteoporosis,

which contributes to reduced bone mass

and increased bone fragility (13).

Because previous research (14–16) has

found that bone density is greater

among black people than among white

people, the prevalence of osteoporosis

and the incidence of fractures would be

expected to be lower in the black

population than in the white population.

Males had significantly higher rates

for intracranial injuries, lacerations and

open wounds, dislocations, burns,

internal injuries, and other injury.

Runyan (17) cited some explanations for

higher rates of injury among males:

more driving by males, more

participation in high risk sports (such as

football), and a greater tendency by

males to acquire weapons. The rate of

motor vehicle injury deaths for males in

1996 was more than twice that for

females, and the firearm death rate for

males was also higher than the rate for

females (4,12).

The 15–24 year olds and the 25–34

year olds had significantly higher rates

of lacerations and open wounds. The

latter group had a significantly higher

rate of intracranial injuries than any of

the age groups under 65. Other research

has documented high young adult

(particularly male) death rates caused by

firearms and motor vehicle-related

injuries (4,12). It is reasonable to

assume that these causes result in

numerous nonfatal injuries for this age

group as well.

The higher rates of lacerations and

open wounds, burns, and internal

injuries for black people could partially

be explained by a greater exposure to

violence. In 1996, cause-of-death

statistics show that the homicide and

legal intervention rate among black

people was 29.8 per 100,000 deaths

compared with 4.7 per 100,000 deaths

for white people (4).

Poisoning rates were higher for

females and for the age groups 15–24

years, 25–34 years, and 35–44 years.

This category does not include drug

dependence or nondependent abuse of

drugs. Forty-three percent of the

poisonings among males and 58 percent

of those for females were caused by

analgesics, antipyretics, and

antirheumatics. This includes aspirin and

acetaminophen (ICD–9–CM code 965)

and psychotropic drugs (ICD–9–CM

969), primarily antidepressants and

tranquilizers. Some of these cases may

have been suicide attempts, which are

more common among females than

among males (18), while others could

have been mistakes. In the absence of

complete E-code data, the extent to

which either is the case is unknown.

Comparison with cause-of-death

statistics is not helpful in this case

because deaths due to drug-induced

causes include a much broader definition

of drug use than the poisoning and toxic

effects category (4).

Beginning with the 25–34 age

group, the rate of miscellaneous

complications of surgical and medical

care increased significantly for each

successive age group. This could be

because as age increases, so do health

problems and encounters with the

medical care system. The complexity of

medical care, and therefore the attendant

risks, would also be expected to increase

with advancing age. Black people also

had a significantly higher rate of these

complications than white people did.

Data from NHDS does not include

information needed to determine how

many medical injuries were due to

medical errors. Some patients may have

received appropriate medical care, but

complications occurred because of the

complexity of the procedures

undertaken, the often fragile condition

of the patient (particularly of the

elderly), and the variability of patient

response to invasive procedures. Others

may have received inappropriate or

inadequate care. Whether these injuries

are medical errors, they are negative

consequences that should be reviewed

by health care providers, and the

findings should be utilized to design

quality improvement programs.

Table 3. Number of days of care and average length of stay of patients discharged from short-stay hospitals by first-listed injury

diagnoses: United States, 1996

[Discharges from non-Federal hospitals. Excludes newborn infants. Diagnostic groupings and code numbers are based on the International Classification of Diseases,

9th Revision, Clinical Modification (ICD–9–CM)]

First-listed diagnosis and ICD–9–CM codes

Days of care

Number

in thousands

Average

length of

stay in days

Fractures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800–829 5,952 5.9

Dislocation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 830–839 64 2.8

Sprains and strains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 840–848 279 2.7

Intracranial injuries (excluding those with skull fracture) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 850–854 940 6.7

Internal injury of chest, abdomen, and pelvis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 860–869 623 7.6

Lacerations, open wounds, injuries to blood vessels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 870–904 461 3.5

Late effects of injury and poisoning1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 905–909 * *

Superficial injuries and contusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 910–924 184 3.0

Burns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 940–949 293 7.8

Other injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 925–939,950–959 193 3.5

Poisoning and toxic effects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 960–989 611 2.9

Other effects of environmental causes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 990–994 74 4.4

Certain adverse effects not elsewhere classified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 995 70 3.1

Miscellaneous complications of surgical and medical care. . . . . . . . . . . . . . . . . . . . . . . . . . . . 996–999 3,955 6.2

* Figure does not meet standard of reliability or precision.

1This category should not be first-listed because it supplements information on a principal diagnosis.

6 Advance Data No. 318 + August 9, 2000
The absence of E-codes for more

than a third of the hospitalizations limits

the ability to use NHDS data to draw

definitive conclusions about the cause

and prevention of injuries. But programs

to reduce the number of injuries have

been designed based on likely causes of

injuries as indicated in other data

sources and publications, many of which

are cited in this paper.

Prevention-of-injury programs

targeted at the elderly population

include providing assistance with

medical management of illness (e.g.,

medication monitoring) (19) and making

their homes safer by eliminating

potential hazards (11). These programs

may potentially reduce the number of

falls that cause fractures as well as other

serious injuries. Prevention and earlier

diagnosis and treatment of osteoporosis

is aimed at reducing fractures in future

elderly populations.

Prevention of injury efforts targeted

at reducing motor vehicle injuries can

especially benefit high-risk groups such

as the elderly, adolescents, and young

adults. Previous prevention efforts in

this area are credited, in part, with a

decline of nearly 30 percent from 1980

to 1997 in the motor vehicle traffic

fatality rate (4,12). This decrease

occurred despite the increase in the

number of miles driven per person

during this period.

Efforts to reduce injuries from

firearms, to improve the safety of

recreational activities, and to identify

and treat those with substance abuse

problems have also been developed to

help reduce injuries particularly in highrisk, younger age groups.

A recent Institute of Medicine

(IOM) report, ‘‘To Err is Human:

Building a Safer Health System,’’ (20)

suggests ways for health providers to

prevent medical mistakes and to

improve patient safety. Hospitals should

find the data in this report on

hospitalization for medical injuries

useful in designing and implementing

the suggested IOM improvements in

their utilization and quality-of-care

review systems.

Data on the utilization of inpatient

hospital care are presented in this report.

Publications covering injury care

delivered in other settings, including the

Table 4. Percent of patients by selected patient and hospital characteristics with firstlisted injury diagnoses discharged from short-stay hospitals with one or more external

cause-of-injury codes (E-codes): United States, 1996

[Discharges from non-Federal hospitals. Excludes newborn infants. Data are for discharges with first-listed

diagnoses of 800–999 from the International Classification of Diseases, 9th Revision, Clinical Modification

(ICD–9–CM), with one or more external cause-of-injury codes]

Characteristic

Percent

with E-code1

All injury and poisoning discharges............................. 63.7

Sex

Male ............................................... 64.9

Female .............................................. 62.5

Age

Under 5 years.......................................... 71.4

5–14 years............................................ 69.7

15–24 years ........................................... 74.4

25–34 years ........................................... 73.0

35–44 years ........................................... 68.0

45–64 years ........................................... 63.0

65–74 years ........................................... 53.9

75 years and over ....................................... 56.5

Race

White ............................................... 62.9

Black ............................................... 69.4

All other ............................................. 60.9

Not stated ............................................ 63.9

Region

Northeast ............................................ 76.6

Midwest ............................................. 58.3

South ............................................... 56.1

West . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69.3

First-listed diagnosis and ICD–9–CM codes

Fractures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800–829 63.4

Dislocation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 830–839 49.3

Sprains and strains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 840–848 47.4

Intracranial injuries (excluding those with skull fracture) . . . . . . . . . . 850–854 67.2

Internal injury of chest, abdomen, and pelvis. . . . . . . . . . . . . . . . . 860–869 60.7

Lacerations, open wounds, injuries to blood vessels . . . . . . . . . . . . 870–904 74.6

Late effects of injury and poisoning2 . . . . . . . . . . . . . . . . . . . . . . 905–909 *

Superficial injuries and contusions . . . . . . . . . . . . . . . . . . . . . . . 910–924 66.4

Burns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 940–949 69.8

Other injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 925–939,950–959 64.6

Poisoning and toxic effects. . . . . . . . . . . . . . . . . . . . . . . . . . . . 960–989 89.5

Other effects of environmental causes. . . . . . . . . . . . . . . . . . . . . 990–994 83.1

Certain adverse effects not elsewhere classified. . . . . . . . . . . . . . . . . . 995 61.4

Miscellaneous complications of surgical and medical care. . . . . . . . . 996–999 56.0

Number of diagnoses

7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60.1

6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71.3

5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69.8

4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71.3

3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75.2

2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60.7

Hospital ownership

Church/nonprofit........................................ 62.4

Proprietary............................................ 59.6

Government ........................................... 73.8

Hospital bed size

6–99 beds ............................................ 64.5

100–299 beds.......................................... 62.1

300–499 beds.......................................... 65.5

500 beds or more ....................................... 64.2

* Figure does not meet standard of reliability or precision.

1E-code is external cause-of-injury and poisoning code.

2This category should not be first-listed because it supplements information on a principal diagnosis.

Advance Data No. 318 + August 9, 2000 7
estimated 34.9 million injury-related

emergency department visits and visits

to outpatient departments and doctors’

offices, have been published (21–23).

Data on nonfatal injury and poisoning

episodes and injury conditions from the

1997 National Health Interview Survey,

a household survey, was recently

published (24).

Throughout this report, the number

of patients are discussed. Because the

data from NHDS are for discharges

rather than for distinct individuals, it

should be noted that patients may be

counted more than once if they have

more than one hospitalization in a year

and if each of their hospital discharges

are included in the sample. This report

presents data on the utilization of

hospital resources so it is appropriate to

include data on each hospitalization

regardless of whether the patient is a

readmission. Those interested in the

number of individual people requiring

hospitalization for injuries in a given

year should be cautioned that the

estimates may be somewhat higher than

the figures needed for their research.

Each of the patient demographic

variables was examined separately by

type of injury because crossing these

data by more than one of these variables

at a time frequently resulted in

unreliable numbers. Future research with

larger samples should permit more

detailed crossing of these variables to

better identify the characteristics of

groups in need of certain intervention

programs.

As stated earlier, the data on race of

patient are incomplete. In 1996, race

was not identified for 22 percent of the

injury discharges. The NHDS data on

race are incomplete largely because a

number of hospitals providing

automated data to NHDS did not

include race data for any of their

patients. Therefore, missing data on the

race variable does not appear to be

related to racial characteristics of the

discharge itself. A study (25) of the

limitations of the NHDS data on race

found that race is more often missing

for white people. NHDS data on race

should be interpreted cautiously when

the differences among racial groups are

small and/or not substantiated by other

research.

NHDS data for 1996 could not be

used to produce reliable, unbiased

national estimates of the causes of

injuries requiring hospitalization.

E-codes were not present for 36 percent

of the records with a first-listed injury

diagnosis. In addition, there is evidence

in the literature that there is bias in the

recording of E-codes. A study of

E-codes in Maryland conducted by

Marganitt and others (26) found a

systematic underreporting of E-codes in

the elderly population, the severely

injured, and patients with long lengths

of hospital stay. These groups were

more likely to have multiple chronic

conditions prior to the injury, more

serious injuries, and/or more

complications during the hospital stay.

In these situations, the data fields

available for recording diagnoses were

likely to be filled, thereby leaving no

room for the E-codes. E-codes are

considered to be of lesser importance to

hospitals because they do not influence

reimbursement. Hence E-codes would be

less likely to be coded than diagnosis

codes.

There is evidence that NHDS data

may become more useful for yielding

reliable data on the causes of injury. The

reporting of E-codes is improving

because more states are mandating their

use. In 1991, only 44 percent of the

diagnoses for injuries included an

E-code, and only 5 states mandated their

use (6). By 1998, 68 percent of these

diagnoses had E-codes, and 23 states

mandated their collection in hospital

data systems (1). As the number of

states mandating the use of E-codes

grows, the likelihood of recording them

on NHDS abstract forms is expected to

increase. Also, many of the forms used

for gathering hospital discharge data are

being expanded to include a larger

number of diagnosis codes. This could

help eliminate the bias against recording

E-codes due to inadequate space.

Information on external causes is

critical for planning, implementing, and

evaluating injury-control programs (11).

Incomplete recording of E-codes limits

the usefulness of hospital discharge data

sources (like NHDS) for injury

surveillance, research, and prevention

(1). A report based on household survey

data gathered in the 1997 National

Health Interview Survey contains

information on the leading external

causes of injury as well as the place of

injury (24). These data, along with

cause of death statistics and smaller

studies of the causes of injuries, can

provide some indication of interventions

that could be designed to prevent or

lessen injuries.

References

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Fingerhut LA, et al. How States are

collecting and using cause of injury

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of the Injury Control and Emergency

Health Services Section of the

American Public Health Association.

1998.

2. Rice DP, MacKenzie EJ, et al. Cost

of injury in the United States: A

report to Congress. University of

California, San Francisco, and the

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3. Miller TR, Lestina DC, Galbraith

MS, Viano DC. Medical-care

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TM et al. Surveillance for injuries

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NC, et al. Epidemiology of

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Advance Data No. 318+ August 9, 20009
Suggested citation

Hall MJ, Owings MF. Hospitalizations for

injury: United States, 1996. Advance data from

vital and health statistics; no 318. Hyattsville,

Maryland: National Center for Health

Statistics, 2000.

Copyright information

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copied without permission; citation as to

source, however, is appreciated.

National Center for Health Statistics

Director

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Deputy Director

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HEALTH & HUMAN SERVICES

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