National Institute on Alcohol Abuse and Alcoholism
Division of Epidemiology and Prevention Research
Alcohol Epidemiologic Data System

SURVEILLANCE REPORT #72

TRENDS IN ALCOHOL-RELATED MORBIDITY
AMONG SHORT-STAY COMMUNITY HOSPITAL
DISCHARGES, UNITED STATES, 1979–2003

Chiung M. Chen, M.A.¹
Hsiao-ye Yi, Ph.D.¹
Michael E. Hilton, Ph.D.²

1 CSR, Incorporated
Suite 1000
2107 Wilson Boulevard
Arlington, VA 22201

2 Division of Epidemiology and Prevention Research
National Institute on Alcohol Abuse and Alcoholism
5635 Fishers Lane, MSC 9304
Bethesda, MD 20892–9304

August 2005

U.S. Department of Health and Human Services
Public Health Service
National Institutes of Health

CSR, Incorporated, operates the Alcohol Epidemiologic Data System (AEDS) under Contract No. N01AA32007 for the Division of Epidemiology and Prevention Research, National Institute on Alcohol Abuse and Alcoholism

HIGHLIGHTS

This surveillance report, prepared annually by the Alcohol Epidemiologic Data System (AEDS), National Institute on Alcohol Abuse and Alcoholism (NIAAA), presents data on alcohol-related morbidity in the United States from 1979 to 2003. AEDS compiles these statistics on alcohol-related inpatient stays based on a national sample of hospital discharge episodes from the National Hospital Discharge Survey (NHDS), conducted by the National Center for Health Statistics (NCHS). Civilian population data estimated by the U.S. Census Bureau are used as the denominators to calculate rates. The following are highlights of general trends and notable findings:

Alcohol-Related Hospital Discharges in 2003

• Approximately 424,000 hospital discharge episodes for persons ages 15 and older had a principal (first-listed) alcohol-related diagnosis, and approximately 1.6 million discharge episodes had an any (all-listed) alcohol-related diagnosis. These figures represent 18.5 principal (first-listed) and 68.8 any (all-listed) alcohol-related discharges per 10,000 population, a slight decline in the principal (first-listed) alcohol-related discharge rate and a slight increase in the any (all-listed) alcohol-related discharge rate compared with the 2002 rates (19.3 and 66.9, respectively).

• Alcohol dependence syndrome composed the largest group (34 percent) of principal (first-listed) diagnoses, followed by alcoholic psychoses (31 percent), cirrhosis of the liver (25 percent), and nondependent abuse of alcohol (10 percent).

• A substantial difference exists between rates based on principal (first-listed) and any (all-listed) diagnoses. More than two-thirds (73 percent) of alcohol-related morbidity episodes did not appear as a principal (first-listed) diagnosis.

• Alcohol-related diagnoses in decreasing order of severity as measured by average length of hospital stay were cirrhosis (5.9 days, with 6.1 days for alcoholic cirrhosis), alcoholic psychoses (5.3 days), alcohol dependence syndrome (4.9 days), and nondependent abuse of alcohol (2.1 days).

General Trends

• Hospital discharge rates showed a clear upward trend for both principal (first-listed) and any (all-listed) alcoholic psychoses as well as for any (all-listed) nondependent abuse of alcohol during 1988 to 2003. The upward trend was less obvious for principal (first-listed) nondependent abuse of alcohol.

• For all alcohol-related diagnoses, except cirrhosis without mention of alcohol, hospital discharge rates continue to be higher for males than for females. Persons ages 45 to 64 generally have the highest any (all-listed) alcohol-related morbidity rates, although persons ages 65 and older have higher rates of cirrhosis without mention of alcohol. Persons ages 15 to 24 have the lowest alcohol-related morbidity rates.

• In terms of percentage shares, the relative ranks of principal (first-listed) alcohol-related diagnoses are fairly constant over the 25-year study period. However, the percentage of alcohol dependence diagnoses has declined substantially in the past few years, while the percentages of diagnoses for alcoholic psychoses and any cirrhosis have increased.

• On average, principal (first-listed) alcohol-related diagnoses accounted for less than one-half (40 percent) of alcohol-related diagnoses in the NHDS samples over the 25-year study period.

• While there has been relatively little change in the percentage of hospital discharges with principal (first-listed) mention of an alcohol-related diagnosis, the proportion of hospital discharges with any (all-listed) mention of an alcohol-related diagnosis has increased.

• For alcohol dependence syndrome and cirrhosis, declines in average length of stay were observed between 1988 and 2003.
  

INTRODUCTION

This is the thirteenth surveillance report on trends in alcohol-related morbidity among patients discharged from short-stay community hospitals in the United States. Prepared by AEDS, NIAAA, the report updates the trends published in earlier surveillance reports as well as a data reference manual (Stinson 1989). The findings are intended to be useful to policymakers, health care providers, researchers, and other individuals concerned about the health effects of alcohol abuse.

Data are presented by age and sex, including numbers and population-based rates for hospital discharges with principal (first-listed) mention or any (all-listed) mention of specific diagnoses for chronic diseases resulting from alcohol abuse. Also included are data on the average length of hospital stay for alcohol-related discharge episodes. Race-specific data are not reported because a large proportion of discharges do not include race information.

AEDS uses variance estimation procedures recommended by NCHS to develop 95 percent confidence intervals for each estimate shown in figure 5 through figure 9 based on relative standard errors. The values of all estimates are presented in tables.

DATA

Sources

Hospital discharge data for the report are obtained from the NHDS, which has been conducted by NCHS since 1965. These data are processed by NCHS and made available on public use computer files. The report begins with 1979, the year in which the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) was implemented. ICD-9-CM is a diagnostic coding scheme published by the Commission on Professional and Hospital Activities (1978) and is based on the World Health Organization’s ninth revision of the ICD (1977). The Tenth Revision of ICD (ICD-10) was implemented for mortality data beginning with data year 1999; the implementation of ICD-10-CM for morbidity data has not yet been determined (NCHS 2004).

The NHDS collects data from a sample of non-Federal, short-stay hospitals with six or more beds and an average length of stay fewer than 30 days. The sample is stratified by geographic region and hospital size. The probability of selecting a hospital is directly proportional to its size. Discharge episodes are sampled randomly at each participating hospital; the episode sampling ratio within an individual hospital varies inversely with the probability of hospital selection. NCHS calculates appropriate weights and includes them in the data files to project national estimates from the sample. Descriptions of the NHDS sampling design, data collection procedures, and data collection instruments used during the 1979–1987 period are published elsewhere by NCHS (1977, 2004, 2005).

In 1988 NCHS implemented a new sample design to (1) provide geographic sampling comparability with other surveys conducted by NCHS, (2) update the sample of hospitals selected for the survey, and (3) maximize the use of data collected through automated systems. This change in the sample design may affect trend data because some differences between NHDS statistics based on the earlier sample (1979–1987) and statistics based on the 1988 sample may be due to sampling variability rather than changes in patterns of hospital utilization (NCHS 2004, 2005). For example, NCHS compared the old survey results with the new results and produced significantly lower estimates of principal (first-listed) and any (all-listed) diagnoses of alcohol dependence in the new series (Haupt and Kozak 1992).

For each hospital discharge episode in the sample, the following items are provided: the patient’s age, sex, race, marital status, and length of stay; the hospital’s size and regional location; and codes for up to seven diagnoses and up to four surgical procedures.

Civilian population data used in calculating hospital discharge rates were estimated by the U.S. Census Bureau and provided by the NCHS.

Definition of Alcohol–Related Diagnoses

Category Used in Report	Classification in ICD–9–CM
Alcoholic psychoses	291.0 Alcohol withdrawal delirium 291.1 Alcohol amnestic syndrome 291.2 Other alcoholic dementia 291.3 Alcohol withdrawal hallucinosis 291.4 Idiosyncratic alcohol intoxication 291.5 Alcoholic jealousy 291.8 Other specific alcoholic psychosis 291.9 Unspecified alcoholic psychosis
Alcohol dependence syndrome	303.0 Acute alcohol intoxication 303.9 Other and unspecified alcohol dependence 265.2 Pellagra 357.5 Alcoholic polyneuropathy 425.5 Alcoholic cardiomyopathy 535.3 Alcoholic gastritis
Nondependent abuse of alcohol	305.0 Alcohol abuse
Chronic liver disease and cirrhosis: Alcoholic cirrhosis of the liver Other specified cirrhosis of the liver without mention of alcohol Unspecified cirrhosis of the liver without mention of alcohol	571.0 Alcoholic fatty liver 571.1 Acute alcoholic hepatitis 571.2 Alcoholic cirrhosis of liver 571.3 Alcoholic liver damage, unspecified 571.4 Chronic hepatitis 571.6 Biliary cirrhosis 571.8 Other chronic nonalcoholic liver disease 572.3 Portal hypertension 571.5 Cirrhosis of liver without mention of alcohol 571.9 Unspecified chronic liver disease without mention of alcohol

For chronic liver disease and cirrhosis, the ICD-9-CM allows for a distinction between diagnoses with and without mention of alcohol. In recent years AEDS has chosen not to emphasize this distinction and has reported all liver cirrhosis in analyses of alcohol-related morbidity and mortality. This practice was adopted at the recommendation of health professionals and epidemiologists who attended a conference sponsored by AEDS in 1979. In keeping with this practice, this report includes an overall category of chronic liver disease and cirrhosis that does not distinguish between cirrhosis with and without mention of alcohol. For consistency with causes of death reported in other AEDS publications on cirrhosis mortality (Yoon, Yi, and Hilton 2005), this report also includes three subcategories of cirrhosis: (1) alcoholic cirrhosis of the liver, (2) other specified cirrhosis of the liver without mention of alcohol, and (3) unspecified cirrhosis of the liver without mention of alcohol.

This report presents data for the U.S. population ages 15 and older in the following age categories: 15 to 24, 25 to 44, 45 to 64, and 65 and older. Age 15 is below the minimum legal drinking age in all 50 States and the District of Columbia, but survey results show that a large number of adolescents drink alcoholic beverages. For example, data from the NIAAA 2001–2002 National Epidemiologic Survey on Alcohol and Related Conditions indicate that 12.2 percent of current drinkers ages 18 and older in the United States began drinking at age 15 or younger (Alcohol Epidemiologic Data System 2004).

Exclusions

In assessing alcohol-related diagnoses, discharges of females with deliveries should be excluded because childbirth is not an illness. In a typical year, approximately 12 to 13 percent of all hospital discharges are for delivery. In 2002 this category accounted for 11.7 percent of all discharges (DeFrances and Hall 2004). Accordingly, to examine the share of all discharges associated with a principal (first-listed) or an any (all-listed) alcohol-related diagnosis in figure 4, the percentages were calculated after excluding from both the numerator and denominator all records coded in the principal (first-listed) diagnosis as V27, a supplementary ICD-9-CM classification for females delivering babies.

Assessment of Statistical Significance

Because data on hospital discharges are based on a sample of all discharges, there is some sampling error in the estimates presented in this report. To assess the statistical significance of apparent differences in the estimates presented, we have used variance estimation procedures recommended by the NCHS to develop confidence intervals for each estimate.

The confidence intervals presented in figures 5–9 are based on relative standard errors (RSEs), which are standard errors expressed as a percentage of the estimate. NCHS provides a method for obtaining RSEs in the technical documentation of the annual National Hospital Discharge Survey summary report for principal (first-listed) and any (all-listed) diagnoses and for length of stay (NCHS 2004, 2005). To obtain a 95-percent confidence interval, the RSE value was multiplied by the estimate and by 1.96, and the resulting value was then added to and subtracted from the estimate.

REFERENCES

Alcohol Epidemiologic Data System. Unpublished data from the 2001–2002 National Epidemiologic Survey on Alcohol and Related Conditions, National Institute on Alcohol Abuse and Alcoholism, 2004.

Commission on Professional and Hospital Activities. The International Classification of Diseases, Ninth Revision, Clinical Modification. Ann Arbor, Michigan, 1978.

DeFrances, C.J., and Hall, M.J. 2002 National Hospital Discharge Survey. Advance Data, Number 342. Hyattsville, MD: National Center for Health Statistics, 2004.

Haupt, B.J., and Kozak, L.J. Estimates From Two Survey Designs: National Hospital Discharge Survey. National Center for Health Statistics. Vital and Health Statistics, Series 13, No. 111. Washington, DC: U.S. Government Printing Office, 1992.

National Center for Health Statistics (W.R. Simmons and G.A. Schnack). Development of the Design of the NCHS Hospital Discharge Survey. Vital and Health Statistics. Series 2, No. 39. U.S. Department of Health, Education and Welfare Publication No. (HRA) 77-1199. Health Resources Administration. Washington, DC: U.S. Government Printing Office, 1977.

National Center for Health Statistics. 1979–2002 National Hospital Discharge Survey (NHDS) Multi-Year Public Use Data File Documentation. Hyattsville, MD: NCHS, 2004.

National Center for Health Statistics. 2003 National Hospital Discharge Survey (NHDS) Public Use Data File Documentation. Hyattsville, MD: NCHS, 2005.

Stinson, F.S. U.S. Alcohol Epidemiologic Data Reference Manual, Volume 4: Hospital Discharges with Alcohol-Related Conditions: Hospital Discharge Survey, 1979–1985. Rockville, MD: National Institute on Alcohol Abuse and Alcoholism, 1989.

World Health Organization. Manual of the International Statistical Classification of Diseases, Injuries, and Causes of Death, Ninth Revision. Geneva: World Health Organization, 1977.

Yoon, Y.H.; Yi, H.; and Hilton, M.E. Surveillance Report #70: Liver Cirrhosis Mortality in the United States, 1970–2002. Bethesda, MD: National Institute on Alcohol Abuse and Alcoholism, Division of Epidemiology and Prevention Research, 2005.

LIST OF FIGURES

Figure 1. Percent distribution of principal (first-listed) diagnoses among discharges with principal (first-listed) mention of an alcohol-related diagnosis, 2003.

Figure 2. Trends in percent distribution of principal (first-listed) diagnoses among discharges with principal (first-listed) mention of an alcohol-related diagnosis, 1979–2003.

Figure 3. Percent distribution of principal (first-listed) diagnoses among discharges with any (all-listed) mention of an alcohol-related diagnosis, 2003.

Figure 4. Trends in percent of discharges with principal (first-listed) or any (all-listed) mention of an alcohol-related diagnosis among all discharges, 1979–2003.

Figure 5. Rates and 95-percent confidence intervals for principal (first-listed) alcohol-related diagnoses, 1979–2003.

Figure 6. Rates and 95-percent confidence intervals for any (all-listed) alcohol-related diagnoses, 1979–2003.

Figure 7. Rates and 95-percent confidence intervals for principal (first-listed) mention of specific alcohol-related diagnoses, 1979–2003.

Figure 8. Rates and 95-percent confidence intervals for any (all-listed) mention of specific alcohol-related diagnoses, 1979–2003.

Figure 9. Average length of stay and 95-percent confidence intervals for specific alcohol-related diagnoses, 1979–2003.

 

LIST OF TABLES

Table 1. Number and rate of principal (first-listed) alcohol-related diagnoses for U.S. population ages 15 years and older by sex and age group, 1979–2003.

Table 2. Number and rate of any (all-listed) alcohol-related diagnoses for the U.S. population ages 15 and older by sex and age group, 1979–2003.

Table 3. Average length of stay (in days) for principal (first-listed) alcohol-related diagnoses by sex and age group, 1979–2003.

 

 

 

Figure 1. Percent distribution of principal (first-listed) diagnoses among discharges with principal (first-listed) mention of an alcohol-related diagnosis, 2003.

 

d

Figure 2. Trends in percent distribution of principal (first-listed) diagnoses among discharges with principal (first-listed) mention of an alcohol-related diagnosis, 1979–2003.

Note: Shaded area represents the period before implementation of a new sample design which may affect the trend data. Caution should be taken when assessing differences between the old and new sample design periods.

Data for figure 2 are presented in the following page.

Figure 3. Percent distribution of principal (first-listed) diagnoses among discharges with any (all-listed) mention of an alcohol-related diagnosis, 2003.

d

Figure 4. Trends in percent of discharges with principal (first-listed) or any (all-listed) mention of an alcohol-related diagnosis among all discharges, 1979–2003.

Note: Shaded area represents the period before implementation of a new sample design which may affect the trend data. Caution should be taken when assessing differences between the old and new sample design periods.

Data for figure 4 are presented in the following page.

 

Figure 5. Rates and 95-percent confidence intervals for principal (first-listed) alcohol-related diagnoses, 1979–2003.

[Vertical axes reflect rates per 10,000 population: scale is not uniform for all graphs]

[Shaded area represents the period before implementation of a new sample design which may affect the trend data. Caution should be taken when assessing differences between the old and new sample design periods.]

 

Data for figure 5 are presented in Table 1.

 

Figure 6. Rates and 95-percent confidence intervals for principal (all-listed) alcohol-related diagnoses, 1979–2003.

[Vertical axes reflect rates per 10,000 population: scale is not uniform for all graphs]

[Shaded area represents the period before implementation of a new sample design which may affect the trend data. Caution should be taken when assessing differences between the old and new sample design periods.]

 

Data for figure 6 are presented in Table 2.

 

Figure 7. Rates and 95-percent confidence intervals for principal (first-listed) mention of specific alcohol-related diagnoses, 1979–2003.

[Vertical axes reflect rates per 10,000 population: scale is not uniform for all graphs]

[Shaded area represents the period before implementation of a new sample design which may affect the trend data. Caution should be taken when assessing differences between the old and new sample design periods.]

Data for figure 7 are presented in Table 1.

 

Figure 8. Rates and 95-percent confidence intervals for any (all-listed) mention of specific alcohol-related diagnoses, 1979–2003.

[Vertical axes reflect rates per 10,000 population: scale is not uniform for all graphs]

[Shaded area represents the period before implementation of a new sample design which may affect the trend data. Caution should be taken when assessing differences between the old and new sample design periods.]

Data for figure 8 are presented in Table 2.

 

Figure 9. Average length of stay and 95-percent confidence intervals for specific alcohol-related diagnoses, 1979–2003.

[Vertical axes reflect average length of stay in days: scale is not uniform for all graphs]

[Shaded area represents the period before implementation of a new sample design which may affect the trend data. Caution should be taken when assessing differences between the old and new sample design periods.]

Data for figure 9 are presented in Table 3.

 

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