NCHS Data Brief ■ No. 43 ■ September 2010

u.s. department of health and human services

Centers for Disease Control and Prevention

National Center for Health Statistics

Emergency Department Visits for Chest Pain and Abdominal 

Pain: United States, 1999–2008

Farida A. Bhuiya, M.P.H.; Stephen R. Pitts, M.D., M.P.H., F.A.C.E.P.; and

Linda F. McCaig, M.P.H., Division of Health Care Statistics

Chest and abdominal pain are the most common reasons that persons aged 

15 years and over visit the emergency department (ED) (1). Because EDs 

provide both emergency and nonemergency care (2,3), visits for these 

symptoms may vary in their acuity. Advanced medical imaging is often 

ordered to assist in both diagnosing and ruling out serious illness associated 

with these symptoms (4,5). This report describes trends in visits for chest and 

abdominal pain in adults and the seriousness of illness and use of imaging in 

these visits. All data shown are for persons aged 18 and over whose visit was 

not injury related.

Keywords: National Hospital Ambulatory Medical Care Survey • advanced 

medical imaging • reason for visit

Are ED visits for chest or abdominal pain increasing?

•	 From 1999 through 2008, the percentage of noninjury ED visits due to 

chest pain decreased, while the percentage of noninjury ED visits due to 

abdominal pain increased (Figure 1).

Key findings

Data from the National 

Hospital Ambulatory Medical 

Care Survey: 1999–2008

•	 The number of noninjury 

emergency department (ED) 

visits in which abdominal pain 

was the primary reason for the 

visit increased 31.8%.

•	 The percentage of ED visits 

for which chest pain was the 

primary reason decreased 10.0%.

•	 Use of advanced medical 

imaging increased strongly for 

ED visits related to abdominal 

pain (122.6%) and chest pain 

(367.6%).

•	 The percentage of ED visits 

for chest pain that resulted in 

a diagnosis of acute coronary 

syndrome decreased 44.9%.

1

Trend is significant (p < 0.05).

NOTE: Figures are based on 2-year averages. 

SOURCE: CDC/NCHS, National Hospital Ambulatory Medical Care Survey, 1999–2008. 

Figure 1. Noninjury emergency department visits for chest pain and abdominal pain for persons 

aged 18 years and over: United States, 1999–2008

Abdominal pain Chest pain1 1

Percent of visits

0

2

4

6

8

10

12

1999–2000 2001–2002 2003–2004 2005–2006 2007–2008

10.0 10.5

9.3

10.6

9.4

11.1

9.1

11.2

9.0

11.3
NCHS Data Brief ■ No. 43 ■ September 2010

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•	 The number of noninjury ED visits rose 22.1%, from 50.5 million in 1999–2000 to 61.7 

million in 2007–2008 (not shown).

•	 The number of noninjury ED visits for which abdominal pain was the primary reason 

increased 31.8%, from 5.3 million in 1999–2000 to 7.0 million in 2007–2008 (not shown). 

The percentage of ED visits for abdominal pain rose 7.6% during this time.

•	 The number of noninjury ED visits in which chest pain was the primary reason was 5.0 

million in 1999–2000 and 5.5 million in 2007–2008, a difference that is not statistically 

significant. The percentage of ED visits for chest pain decreased 10.0% during this time,

from 10.0% to 9.0%.

Is ambulance use increasing among patients complaining of chest or 

abdominal pain? 

•	 The percentage of noninjury ED visits in which patients with abdominal pain arrived by 

ambulance was 26.9% higher in 2007–2008 than in 1999–2000. No significant difference

was observed when comparing percentages of visits for chest pain and arrival by ambulance 

for the same years (Figure 2).

NOTES: Figures are based on 2-year averages. Mode-of-arrival data are not available for 2001 and 2002.

SOURCE: CDC/NCHS, National Hospital Ambulatory Medical Care Survey, 1999–2008.

Figure 2. Arrival by ambulance for noninjury emergency department visits for persons aged 18 years and over:

United States, 1999–2008 Percent of visits

25.5

10.0

15.6

22.7

11.3

16.0

26.6

12.4

15.0

25.8

12.6

16.0

0

5

10

15

20

25

30

1999–2000 2003–2004 2005–2006 2007–2008

Chest pain Abdominal pain Other symptoms

•	 In each time period studied, patients with chest pain were more likely to arrive by 

ambulance compared with patients having other symptoms. Conversely, patients with 

abdominal pain were less likely to arrive by ambulance compared with patients having

other symptoms.
NCHS Data Brief ■ No. 43 ■ September 2010

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Are chest or abdominal pain visits triaged as immediate or emergent 

becoming more common?

•	 Triage level indicates the seriousness of the visit from the perspective of the triage nurse. 

•	 From 1999–2000 through 2007–2008, the percentage of chest pain visits triaged as 

immediate or emergent (i.e., should be seen within 14 minutes) decreased by 12.4%. 

•	 The percentage of noninjury ED visits for symptoms other than chest pain or abdominal 

pain that were triaged as immediate or emergent also decreased, by 6.4% (Figure 3).

1

Trend is significant (p < 0.05).

NOTES: Figures are based on 2-year averages. Emergent visits are those in which the patient should be seen within 14 minutes.

SOURCE: CDC/NCHS, National Hospital Ambulatory Medical Care Survey, 1999–2008. 

Figure 3. Immediate and emergent noninjury emergency department visits for persons aged 18 years and over: 

United States, 1999–2008 Percent of visits

43.4

13.7

17.2

48.0

20.4 20.8

37.7

12.1

14.4

39.8

13.5 14.7

38.0

12.5

16.1

Other symptoms Abdominal pain 1 Chest pain1

0

10

20

30

40

50

1999–2000 2001–2002 2003–2004 2005–2006 2007–2008

•	 No trend was found for abdominal pain visits triaged as immediate or emergent. 

•	 The percentage of chest pain visits that were immediate or emergent was two to three times 

higher than the percentage of visits for abdominal pain or visits for other symptoms.

Is the use of advanced medical imaging for chest or abdominal pain visits 

increasing?

•	 Ordering advanced medical imaging for diagnosis of illness indicates the physician’s 

perception of the visit’s seriousness. 

•	 A trend toward increased use of advanced medical imaging during noninjury ED visits was 

observed from 1999–2000 through 2007–2008 for chest pain visits (up 367.6%, from 3.4% 

to 15.9%), abdominal pain visits (up 122.6%, from 19.9% to 44.3%), and all other visits

(up 122.1%, from 8.6% to 19.1%) (Figure 4).
NCHS Data Brief ■ No. 43 ■ September 2010

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1

Trend is significant (p < 0.05).

NOTE: Figures are based on 2-year averages. 

SOURCE: CDC/NCHS, National Hospital Ambulatory Medical Care Survey, 1999–2008.

Figure 4. Advanced medical imaging among noninjury emergency department visits for persons aged 18 years and over:

United States, 1999–2008 Percent of visits

Other symptoms Abdominal pain1 1 Chest pain1

3.4

19.9

8.6

4.1

25.8

10.8

7.9

31.2

13.1 10.9

40.8

15.8 15.9

44.3

19.1

0

10

20

30

40

50

1999–2000 2001–2002 2003–2004 2005–2006 2007–2008

Are visits to the ED for abdominal or chest pain becoming less serious?

•	 The percentage of ED visits for chest pain that resulted in a diagnosis of acute coronary 

syndrome (ACS) decreased 44.9%, from 23.6% in 1999–2000 to 13.0% in 2007–2008.

•	 During the same time period, no significant change was observed in the percentage of ED

visits for abdominal pain that resulted in a serious diagnosis (Figure 5).

1

Trend is significant (p < 0.05).

NOTES: Figures are based on 2-year averages. Serious diagnosis is defined by the International Classification of Diseases, Ninth Revision, Clinical Modification

codes. Serious abdominal diagnoses are defined as codes 540, 541, 560.8, 560.9, 574, 575.0, 575.1, 575.2, 575.4, 577.0, 578.9, 590.80, 590.81, 592.0, 592.1, 

633.1, 633.8, 633.9, or 788.0. Acute coronary syndrome is defined as codes 410–414. 

SOURCE: CDC/NCHS, National Hospital Ambulatory Medical Care Survey, 1999–2008.

Figure 5. Chest pain- and abdominal pain-related emergency department visits for persons aged 18 years and over with a 

serious diagnosis: United States, 1999–2008 Percent of visits

Abdominal pain visits with

serious diagnosis

Chest pain visits with

acute coronary syndrome1

17.4

23.6

22.0

17.8

19.8

17.7 16.8 16.8

13.0

17.1

0

5

10

15

20

25

1999–2000 2001–2002 2003–2004 2005–2006 2007–2008
NCHS Data Brief ■ No. 43 ■ September 2010

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Are patients with chest or abdominal pain becoming more likely to die in

the ED, be admitted to the hospital, or be transferred to another facility

over time?

•	 In each time period studied, patients with chest pain were more likely to die, be admitted to 

the hospital, or be transferred to another facility compared with visits for abdominal pain or 

other symptoms (Figure 6). 

1

Trend is significant (p < 0.05).

NOTES: Figures are based on 2-year averages. The Patient Record form included a “Transfer to other facility” checkbox for 1999–2006; the wording was changed 

to “Transfer to different hospital” for 2007–2008. Patients dead on arrival were included as visits because they could not be separated from those who died in the 

emergency department for 1999–2006.

SOURCE: CDC/NCHS, National Hospital Ambulatory Medical Care Survey, 1999–2008.

Figure 6. Hospital admission, transfer, or death among emergency department visits for persons aged 18 years and over: 

United States, 1999–2008 Percent of visits

0

10

20

30

40

50

1999–2000 2001–2002 2003–2004 2005–2006 2007–2008

42.5

20.7 20.1

37.7

20.1 18.6

42.3

21.6 21.1

37.6

19.4 18.0

35.2

19.8 18.9

Chest pain Abdominal pain Other symptoms 1

•	 The percentage of visits for chest pain that resulted in admission, transfer, or death declined 

17.2% from 1999–2000 through 2007–2008. 

•	 No trend was observed in visits for abdominal pain resulting in admission, transfer, or death 

during this time.
NCHS Data Brief ■ No. 43 ■ September 2010

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Summary

The number of noninjury ED visits made by persons aged 18 and over complaining of chest pain 

or abdominal pain rose from 1999 through 2008, but the proportion of those visits with a serious 

diagnosis did not increase. In fact, the percentage of visits for chest pain resulting in a diagnosis 

of ACS decreased, consistent with reported declines in hospitalizations for acute myocardial 

infarction (4). However, not all indicators of acuity follow the same pattern. Arrival by ambulance 

increased for abdominal pain visits, while the proportion of visits triaged as immediate or 

emergent declined for chest pain visits as well as for visits with other symptoms. The proportion 

of visits in which the patient was admitted to the hospital, transferred to another facility, or died 

decreased for chest pain visits but remained constant for abdominal pain visits. In contrast, the 

use of advanced medical imaging increased dramatically for these visits. Advanced imaging 

may increase the amount of time that a patient spends in the ED, thereby slowing throughput 

and contributing to ED crowding and its adverse consequences (5–7). However, advanced 

imaging may help a physician to rule out conditions, thereby avoiding further unnecessary 

or risky diagnosis and therapy, and it may help confirm certain conditions, thereby leading to

more effective and efficient therapy (7,8). Targeted research is needed to clarify the extent to

which medical imaging for ED visits for chest or abdominal pain is improving the diagnosis and 

treatment of serious conditions.

Definitions

Emergency department (ED): A hospital facility that provides unscheduled outpatient services to 

patients whose conditions require immediate care, which is staffed 24 hours a day. On- and offsite EDs that are open fewer than 24 hours are included if staffed by the hospital.

Emergency department visit: A direct, in-person exchange between a patient seeking ED care and

a health care provider.

Patient’s principal reason for visit: Main complaint, symptom, or reason the patient came to 

the ED, coded according to A Reason for Visit Classification for Ambulatory Care (RVC) (9). 

Abdominal pain symptoms were defined as stomach and abdominal pain, cramps and spasms

(RVC code 1545). Chest pain symptoms were defined as chest pain and related symptoms (RVC

code 1050).

Serious diagnosis: Up to three diagnoses coded according to the International Classification of 

Diseases, Ninth Revision, Clinical Modification (ICD–9–CM) (10). Serious abdominal diagnosis 

was defined as ICD–9–CM codes 540, 541, 560.8, 560.9, 574, 575.0, 575.1, 575.2, 575.4, 577.0,

578.9, 590.80, 590.81, 592.0, 592.1, 633.1, 633.8, 633.9, and 788.0. Acute coronary syndrome 

was defined as ICD–9–CM codes 410–414.

Advanced medical imaging: Includes computerized tomography or CT scan, magnetic resonance 

imaging or MRI, and ultrasound technology.
NCHS Data Brief ■ No. 43 ■ September 2010

■  7  ■

Data source and methods

Data from the 1999–2008 National Hospital Ambulatory Medical Care Survey (NHAMCS) were 

used for this analysis. NHAMCS is an annual national probability sample survey of nonfederal, 

general, and short-stay hospitals. It is designed to produce national estimates of visits to EDs and 

outpatient departments, including statistics on patient demographic characteristics, reasons for 

visit, diagnoses, services, medications, and disposition.

The ED component of NHAMCS has a multistage design that involves sampling geographic 

primary sampling units (PSUs), hospitals that have EDs within PSUs, and patient visits within 

emergency service areas (ESAs). Types of ESAs included general, adult, pediatric, fast track, 

psychiatric, and trauma. During the study period, approximately 480 hospitals were selected

each year, of which about 415 had eligible EDs. Each year, data are collected on about 35,000 

ED visits. Data were combined for 2-year periods to provide more reliable estimates. The study 

excluded injury-related visits.

Data analyses were performed using the statistical packages SAS version 9.2 (SAS Institute, 

Cary, N.C.) and SUDAAN version 9.0 (Research Triangle Institute, Research Triangle Park, 

N.C.) A weighted least squares regression analysis was used to determine the significance of

trends at the 0.05 level. Terms relating to differences such as “greater than” or “less than” indicate 

that the difference is statistically significant. A lack of comment regarding the difference does not

mean that the difference was tested and found not significant.

About the authors

Farida Bhuiya and Linda McCaig are with the Centers for Disease Control and Prevention’s 

National Center for Health Statistics, Division of Health Care Statistics, Ambulatory and Hospital 

Care Statistics Branch. Stephen Pitts is with Emory University School of Medicine, Department 

of Emergency Medicine.

References

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4. Fang J, Alderman MH, Keenan NL, Ayala C. Acute myocardial infarction hospitalization in 

the United States, 1979 to 2005. Am J Med 123(3):259–66. 2010.

5. Gardner RL, Sarkar U, Maselli JH, Gonzales R. Factors associated with longer ED lengths of 

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8. Gerhardt RT, Nelson BK, Keenan S, Kernan L, MacKersie A, Lane 

MS. Derivation of a clinical guideline for the assessment of nonspecific

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9. Schneider D, Appleton L, McLemore T. A reason for visit classification

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10. CDC, National Center for Health Statistics and Centers for Medicare & 

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Clinical Modification, Sixth Edition. DHHS Pub No. (PHS) 06–1260. 2006.

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Suggested citation

Bhuiya F, Pitts SR, McCaig LF. Emergency 

department visits for chest pain and 

abdominal pain: United States, 1999–2008. 

NCHS data brief, no 43. Hyattsville, MD: 

National Center for Health Statistics. 2010.

Copyright information

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the public domain and may be reproduced 

or copied without permission; citation as to 

source, however, is appreciated.

National Center for Health 

Statistics

Edward J. Sondik, Ph.D., Director

Jennifer H. Madans, Ph.D., Associate 

Director for Science

Division of Health Care Statistics

Jane E. Sisk, Ph.D., Director