Trends in hospital emergency department utilization: United States, 1992-99.

OBJECTIVES: This report describes trends in hospital emergency department (ED) visits in the United States. Statistics are presented for overall utilization, case mix of patients, services provided, and outcome measures. METHODS: The data presented in this report were collected from the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 1992 through 1999. To make the data points more reliable for trend analysis, the data were combined to provide 2-year annual averages for 1993-94, 1995-96, and 1997-98. The survey in 1992 was especially large so it was used alone. The 1999 data are the most recent year available and are presented separately. RESULTS: The volume of ED visits in the United States increased by 14% from 1992 through 1999, from 89.8 million to 102.8 million annually. This increase is mainly due to an increase in visits for illness-related as opposed to injury-related conditions. Although the population rate for ED visits did not significantly increase over this time period (rates between 35.7 and 37.9 visits per 100 persons), the rate for illness-related visits rose from 21.0 to 24.0 visits per 100 persons (p < 0.01). The most dramatic increases were observed in the overall visit rate for black persons 65 years of age and over, which rose by 59% from 45.4 visits per 100 persons in 1992 to 72.2 in 1999. For black seniors, both illness and injury-related visit rates increased at a much higher rate compared with trends for white seniors. CONCLUSION: Increased volume of ED encounters for persons 45 years of age and over was associated with a greater proportion of illness conditions presenting to the ED and the use of more services, medications, and mid-level providers.

Use of physician assistants and nurse practitioners in primary care, 1995-1999.

Federal policies and state legislation encourage the use of physician assistants (PAs) and nurse practitioners (NPs) in primary care, although the nature of their work has not been fully analyzed. In this paper we analyze primary care physician office encounter data from the 1995-1999 National Ambulatory Medical Care Surveys. About one-quarter of primary care office-based physicians used PAs and/or NPs for an average of 11 percent of visits. The mean age of patients seen by physicians was greater than that for PAs or NPs. NPs provided counseling/education during a higher proportion of visits than did PAs or physicians. Overall, this study suggests that PAs and NPs are providing primary care in a way that is similar to physician care.

Use of physician assistants and nurse practitioners in primary care, 1995-1999.

Federal policies and state legislation in the United States encourage the use of physician assistants (PAs) and nurse practitioners (NPs) in primary care, although the nature of their work has not been fully analyzed. This article analyzes primary care physician office-encounter data from the 1995-1999 National Ambulatory Medical Care Surveys. About one-quarter of primary care office-based physicians used PAs and/or NPs for an average of 11% of visits. The mean age of patients seen by physicians was greater than that for PAs or NPs. NPs provided counselling/education during a higher proportion of visits than did PAs or physicians. Overall, this study suggests that PAs and NPs are providing primary care in a way that is similar to physician care.

National Hospital Ambulatory Medical Care Survey: 1999 emergency department summary.

OBJECTIVES: This report describes ambulatory care visits to hospital emergency departments (ED's) in the United States. Statistics are presented on selected hospital, patient, and visit characteristics. Highlights of trends in ED utilization from 1992 through 1999 are also presented. METHODS: The data presented in this report were collected from the 1999 National Hospital Ambulatory Medical Care Survey (NHAMCS). NHAMCS is part of the ambulatory care component of the National Health Care Survey that measures health care utilization across various types of providers. NHAMCS is a national probability survey of visits to hospital emergency and outpatient departments of non-Federal, short-stay, and general hospitals in the United States. Sample data are weighted to produce annual national estimates. Trends are based on NHAMCS data for 1992, 1993-94, 1995-96, 1997-98, and 1999. RESULTS: During 1999, an estimated 102.8 million visits were made to hospital ED's in the United States, about 37.8 visits per 100 persons. The volume of ED visits increased by 14 percent from 1992 through 1999, though no trend was observed in the overall population-based visit rates. There was a significant increase in the visit rate for black persons 75 years of age and over. In 1999, persons 75 years of age and over had the highest ED visit rate and 41.5 percent of these patients arrived by ambulance. There were an estimated 37.6 million injury-related ED visits during 1999, or 13.8 visits per 100 persons. Seventy-four percent of injury-related ED visits were made by persons under 45 years of age. Injury visit rates were higher for males than females in each age group under 45 years. The case mix of visits at ED's changed since 1992, with a greater percent of visits presenting with illness rather than injury conditions. Abdominal pain, chest pain, fever, and headache were the leading patient complaints accounting for one-fifth of all visits. Acute upper respiratory infection was the leading illness-related diagnosis at ED visits. Increases were observed in visits where no complete diagnosis could be made (16.2 percent of visits in 1999). Diagnostic and/or screening services were provided at 89.0 percent of visits, procedures were performed at 42.5 percent of visits, and medications were provided at 72.5 percent of visits. Pain relief drugs accounted for 31.1 percent of the medications mentioned. Trend data from 1992 indicated that the use of medications at ED visits increased. In 1999, approximately 13 percent of ED visits ended in hospital admission. Facility-level data indicated that there is variation among hospital ED's with respect to case mix, number of services provided, and case disposition distributions, especially the percent admitted to the hospital.

National Hospital Ambulatory Medical Care Survey: 1998 outpatient department summary.

OBJECTIVE: This report describes ambulatory care visits to hospital outpatient departments in the United States. Statistics are presented on selected hospital, clinic, patient, and visit characteristics. METHODS: The data presented in this report were collected from the 1998 National Hospital Ambulatory Medical Care Survey (NHAMCS). NHAMCS is part of the ambulatory care component of the National Health Care Survey that measures health care utilization across various types of providers. NHAMCS is a national probability sample survey of visits to hospital outpatient and emergency departments of non-Federal, short-stay, and general hospitals in the United States. Sample data are weighted to produce annual estimates. RESULTS: During 1998, an estimated 75.4 million visits were made to hospital outpatient departments in the United States, an overall rate of 28.0 per 100 persons. Visit rates did not vary by age except in a comparison of the 15-24 year old group with the 75 years and over age group. Black persons had higher rates of visits than white persons as did women compared with men. Of all visits made to hospital outpatient departments in 1998, 33.8 percent and 25.9 percent, respectively, listed private insurance and Medicaid as the primary expected source of payment, and 21.9 percent were made by patients belonging to a health maintenance organization. There were an estimated 7.1 million injury-related outpatient department visits during 1998.

National Hospital Ambulatory Medical Care Survey: 1998 emergency department summary.

OBJECTIVES: This report describes ambulatory care visits to hospital emergency departments in the United States. Statistics are presented on selected patient and visit characteristics. METHODS: The data presented in this report were collected from the 1998 National Hospital Ambulatory Medical Care Survey (NHAMCS). NHAMCS is part of the ambulatory care component of the National Health Care Survey that measures health care utilization across various types of providers. NHAMCS is a national probability survey of visits to hospital emergency and outpatient departments of non-Federal, short-stay, and general hospitals in the United States. Sample data are weighted to produce annual national estimates. RESULTS: During 1998, an estimated 100.4 million visits were made to hospital emergency departments (ED's) in the United States, about 37.3 visits per 100 persons. Persons 75 years and over had the highest rate of ED visits. There were an estimated 37.1 million injury-related ED visits during 1998, or 13.8 visits per 100 persons. Seventy-four percent of injury-related ED visits were made by persons under 45 years of age. Injury visit rates were higher for males than females in each age group under 45 years. According to ICD-9-CM classification, 77.2 percent of injury visits were unintentional. About 71 percent of the ED visits involved medication therapy, with pain relief drugs accounting for 31.5 percent of the medications mentioned. Acute upper respiratory infection was the leading illness-related diagnosis at ED visits.

Food-related illness and death in the United States.

To better quantify the impact of foodborne diseases on health in the United States, we compiled and analyzed information from multiple surveillance systems and other sources. We estimate that foodborne diseases cause approximately 76 million illnesses, 325,000 hospitalizations, and 5,000 deaths in the United States each year. Known pathogens account for an estimated 14 million illnesses, 60, 000 hospitalizations, and 1,800 deaths. Three pathogens, Salmonella, Listeria, and Toxoplasma, are responsible for 1,500 deaths each year, more than 75% of those caused by known pathogens, while unknown agents account for the remaining 62 million illnesses, 265,000 hospitalizations, and 3,200 deaths. Overall, foodborne diseases appear to cause more illnesses but fewer deaths than previously estimated.

Poisoning-related visits to emergency departments in the United States, 1993-1996.

BACKGROUND: Poisoning continues to be an important public health problem in the US. In 1995, 2 million human poison exposures were reported to all poison centers in the US. Hospital emergency department data may be used to examine the most critical nonfatal poisoning exposures. METHODS: Data from the 1993-1996 National Hospital Ambulatory Medical Care Survey, which is a national probability sample survey of visits to emergency departments of nonFederal, short-stay, and general hospitals, were examined to describe poisoning-related emergency department visits in the US. RESULTS: During 1993-1996, the average annual number of emergency department visits was 93 million, of which 37 million were injury related and 1 million were poisoning related. Children under 5 years of age had a significantly higher average annual rate of poisoning-related visits (84 visits per 10,000 persons) than persons 5-19 years of age and persons 35 years of age and over. "Poisoning by other and unspecified drugs and medicinal substances" was the leading diagnosis and was recorded at 21% of all poisoning-related visits. Poisoning-related visits were more often recorded as urgent (75%) and were more likely to result in hospital admission (22%) compared to illness visits (45% and 17%, respectively) and nonpoisoning-related injury visits (47% and 6%, respectively). CONCLUSIONS: Poisoning-related injury visits comprise a small (1%), but important component of the health care provided in emergency departments. An examination of different definitions of poisoning revealed that for emergency department data, it is most appropriate to use the poisoning E-codes from the injury data framework developed by the injury control community. Data from emergency departments are needed to monitor any changing patterns of nonfatal poisonings and to provide guidance for effective poison prevention programs.

National Hospital Ambulatory Medical Care Survey: 1997 outpatient department summary.

OBJECTIVE: This report describes ambulatory care visits to hospital outpatient departments in the United States. Statistics are presented on selected hospital, clinic, patient, and visit characteristics. METHODS: The data presented in this report were collected from the 1997 National Hospital Ambulatory Medical Care Survey (NHAMCS). NHAMCS is part of the ambulatory care component of the National Health Care Survey that measures health care utilization across various types of providers. NHAMCS is a national probability sample survey of visits to hospital outpatient and emergency departments of non-Federal, short-stay, and general hospitals in the United States. Sample data are weighted to produce annual estimates. RESULTS: During 1997, an estimated 77.0 million visits were made to hospital outpatient departments in the United States, an overall rate of 28.9 per 100 persons. Visit rates did not vary by age. Black persons had higher rates of visits than white persons. Of all visits made to hospital outpatient departments in 1997, 34.1 percent and 27.8 percent, respectively, listed private insurance and Medicaid as the primary expected source of payment, and 20.1 percent were made by patients belonging to a health maintenance organization. There were an estimated 7.1 million injury-related outpatient department visits during 1997.

A comparison of work-related injury visits and other injury visits to emergency departments in the United States, 1995-1996.

Estimates of nonfatal work-related injuries range from 6 to 13 million annually, and the most serious of these injuries are presented to hospital emergency departments (EDs). To describe work-related injury ED visits in the United States, we examined data from the 1995-1996 National Hospital Ambulatory Medical Care Survey, which is a national probability sample survey of visits to EDs of non-federal, short-stay, and general hospitals. In 1995-1996, an annual average of 4 million work-related injury ED visits were made by persons 16 years of age and over. The average annual rate of work-related injury visits was 3.5 per 100 workers, and the rate of nonwork-related injury visits was 11.2 per 100 persons. Persons 16-19 years of age had a higher work-related injury visit rate (6.9 per 100 full-time equivalents [FTEs]) than did those 20 years of age and over (3.4 per 100 FTEs). Males had higher work-related injury visit rates (4.3 per 100 FTEs) than females (2.4 per 100 FTEs). The leading cause of injury and diagnosis for work-related injury ED visits were "cuts" (16%) and "open wound" (22%), respectively. Determining appropriate preventive action will reduce the number of workers injured and may result in financial savings for industries and health care systems.

Physician assistants and nurse practitioners in hospital outpatient departments, 1993-1994.

OBJECTIVE: To describe the characteristics of visits to physician assistants (PAs) and nurse practitioners (NPs) in hospital outpatient departments in the United States. METHODS: Data from the 1993 and 1994 National Hospital Ambulatory Medical Care Surveys were used to compare hospital outpatient department visits in which the patient was seen by a PA or NP, or both, with outpatient visits to all practitioners. RESULTS: An average of 64 million annual outpatient visits were made in 1993-1994, and patients were seen by PAs, NPs, or both, at 8% of these visits. PA-NP visits were more likely than total visits to occur in the Midwest, in non-urban areas, and in obstetric-gynecology clinics, and a higher proportion involved patients younger than age 25. Smaller differences were found between PA-NP visits and total outpatient visits in "reason for visit," "principal diagnosis," and "medication prescribed." CONCLUSION: Beyond the care they provide in physicians' offices and other non-hospital settings, PAs and NPs make an important contribution to ambulatory health care delivery in hospital outpatient departments.

National Hospital Ambulatory Medical Care Survey: 1996 emergency department summary.

OBJECTIVES: This report describes ambulatory care visits to hospital emergency departments in the United States. Statistics are presented on selected patient and visit characteristics. METHODS: The data presented in this report were collected from the 1996 National Hospital Ambulatory Medical Care Survey (NHAMCS). NHAMCS is part of the ambulatory care component of the National Health Care Survey that measures health care utilization across various types of providers. NHAMCS is a national probability survey of visits to hospital emergency and outpatient departments of non-Federal, short-stay, and general hospitals in the United States. Sample data were weighted to produce annual estimates. RESULTS: During 1996, an estimated 90.3 million visits were made to hospital emergency departments (ED's) in the United States, about 34.2 visits per 100 persons. Persons 75 years and over had the highest rate of emergency department visits. There were an estimated 34.9 million injury-related emergency department visits during 1996, or 13.2 visits per 100 persons. There were 110,000 visits related to injuries caused by firearms, including 73,000 visits for gunshot wounds. Almost one-fifth of the injury visits were work-related for persons 18-64 years of age. Almost four-fifths of the ED visits involved medication therapy. Pain relief drugs accounted for almost 30 percent of the medications mentioned. Acute upper respiratory infection was the leading illness related diagnosis for ED visits.

National Hospital Ambulatory Medical Care Survey: 1996 outpatient department summary.

OBJECTIVE: This report describes ambulatory care visits to hospital outpatient departments in the United States. Statistics are presented on selected patient and visit characteristics. METHODS: The data presented in this report were collected from the 1996 National Hospital Ambulatory Medical Care Survey (NHAMCS). NHAMCS is part of the ambulatory care component of the National Health Care Survey that measures health care utilization across various types of providers. NHAMCS is a national probability survey of visits to hospital outpatient and emergency departments of non-Federal, short-stay, and general hospitals in the United States. Sample data were weighted to produce annual estimates. RESULTS: During 1996, an estimated 67.2 million visits were made to hospital outpatient departments in the United States, about 25.4 visits per 100 persons. Overall, visits rates did not vary by age. Females and black persons had higher rates of visits than males and white persons, respectively. There were an estimated 6.8 million injury--related outpatient department visits during 1996.

National Hospital Ambulatory Medical Care Survey: 1995 outpatient department summary.

OBJECTIVE: This report describes outpatient department visits in the United States in 1995. Statistics are presented on selected patient and visit characteristics. METHODS: The data presented in this report were collected from the 1995 National Hospital Ambulatory Medical Care Survey (NHAMCS). NHAMCS is part of the ambulatory care component of the National Health Care Survey, which measures health care utilization across various types of providers. NHAMCS is a national probability survey of visits to outpatient departments and emergency departments of non-Federal, short-stay and general hospitals in the United States. Sample data were weighted to produce annual estimates. RESULTS: During 1995, an estimated 67.2 million visits were made to hospital outpatient departments in the United States, an overall rate of 25.7 visits per 100 persons. Overall, visit rates did not vary by age. Females and black persons had higher rates of visits than males and whites, respectively. There were an estimated 7.3 million injury-related outpatient department visits in 1995.

Trends in antimicrobial drug prescribing among office-based physicians in the United States.

OBJECTIVE: To assess changes in oral antimicrobial drug prescribing by office-based physicians from 1980 through 1992, with emphasis on the treatment of otitis media and sinusitis and on the possible impact of demographic variables on such use. DESIGN: The National Ambulatory Medical Care Survey is a sample survey of office-based physicians in the United States conducted by the National Center for Health Statistics, Centers for Disease Control and Prevention. SETTING: Physicians' offices. PATIENTS OR OTHER PARTICIPANTS: Physicians sampled for the 1980, 1985, 1989, and 1992 National Ambulatory Medical Care Surveys, which included groups of 2959, 5032, 2540, and 3000 physicians, respectively. Sample physicians responding in 1980, 1985, 1989, and 1992 reported data for 46,081, 71,594, 38,384, and 34,606 sample office visits, respectively, including information on antimicrobial drug prescribing. MAIN OUTCOME MEASURE: Trends in the antimicrobial drug prescription rates. RESULTS: From 1980 through 1992, increasing prescribing measured by the annual drug prescription rate per 1000 population, was found for the more expensive, broad-spectrum antimicrobial drugs, such as the cephalosporins; decreasing rates were observed for less expensive antimicrobial drugs with a narrower spectrum, such as the penicillins. No trend was found for trimethoprim-sulfamethoxazole, the erythromycins, or the tetracyclines. During the decade, an increasing trend in the visit rate to office-based physicians for otitis media was observed, while the visit rate for sinusitis among adults was found to be higher in 1992 than in each of the other study years. CONCLUSIONS: The increased use of broader-spectrum and more expensive antimicrobial drugs have implications for all patients because of the impact on health care costs and the potential for the emergence of antimicrobial resistance. The data suggest that the incidence of otitis media and sinusitis is increasing.

Plan and operation of the National Hospital Ambulatory Medical Survey. Series 1: programs and collection procedures.

This report describes the methods used in the 1992 National Ambulatory Medical Care Survey. This survey is based on data obtained from the national probability sample of visits to hospital emergency and outpatient departments.

Epidemiologic aspects of a St. Louis encephalitis outbreak in Fort Walton Beach, Florida in 1980.

From July 10 through August 4, 1980, five cases of St. Louis encephalitis (SLE) occurred in and near Fort Walton Beach on the Gulf Coast of northwest Florida. These were the first cases of SLE ever reported from the Florida panhandle. To determine the extent of SLE infection in the community, sera (n = 968) were collected from patients at the local hospital and county public health unit and tested for SLE virus antibody. The SLE attack rate was highest in a centrally located impoverished census tract. There was a trend toward decreasing seroprevalence with distance from the central area of the city. Overall, seroprevalence was higher in males (prevalence ratio = 2.7) and in all areas, seroprevalence increased with age. The serosurvey results suggest that SLE has been endemic in the Fort Walton Beach area.

Knowledge about AIDS and HIV in the US adult population: influence of the local incidence of AIDS.

BACKGROUND: Accurate information about acquired immunodeficiency syndrome (AIDS) and human immunodeficiency virus (HIV) is important for prevention. This study determined whether AIDS knowledge varied among populations residing in areas with a low, medium, or high incidence of AIDS. METHODS: Respondents to the 1988 National Health Interview Survey of AIDS Knowledge and Attitudes, which is based on a nationally representative sample of 29,659 adults, were rated on their knowledge about modes of HIV transmission, general knowledge about AIDS, and misperceptions about HIV transmission through casual contact. RESULTS: Persons 50 years of age or older, Blacks, Hispanics, and persons with less than a high school education had lower knowledge scores and higher misperception scores. Residents of the high-incidence area had more misperceptions than those who lived in the medium- or low-incidence areas. Sociodemographic determinants of scores were important factors overall and within each AIDS incidence area. CONCLUSIONS: These data suggest that the ability of educational messages to reach and be absorbed by individuals nationwide is less dependent on whether they live in an area with a high incidence of AIDS and more dependent on other demographic variables. New and continued efforts are needed to improve knowledge in older persons, minorities, and the less educated in all parts of the country.