The Risk of Appendiceal Rupture Based on Hospital Admission Source

OBJECTIVE: To determine whether admission source is a potential risk factor for appendiceal rupture. METHODS: Administrative data were obtained from the California Office of Statewide Health Planning and Development for all patients in San Diego County with the primary diagnosis of appendicitis during 1993. The appendiceal rupture ratio was defined as those coded as ruptured (ICD-9-CM codes 540.0 and 540.1) divided by both ruptured and non-ruptured cases (540.9). The odds ratio of appendiceal rupture from routine outpatient office or clinic venues vs those admitted through the ED were calculated using multivariate logistic regression analysis to adjust for age, sex, race, comorbidity, insurance status, and home address to hospital proximity. RESULTS: There were a total of 1,906 patients, of whom 663 (34.8%) had appendiceal ruptures. Of the 1,360 (71.4%) admitted from the ED, 422 (31.0%) had ruptures, compared with 211 (43.3%) of the 487 admitted from outpatient sources (p < 0.0001). Patients with appendicitis directly admitted from outpatient sources were more likely to be complicated by appendiceal rupture than were those admitted through the hospital ED (adjusted odds ratio 1.62, 95% CI = 1.28 to 2.05, p < 0.0001). CONCLUSION: Patients with appendicitis admitted from outpatient sources are more likely to have appendiceal rupture than are those admitted from the ED.     

Racial disparities in mortality among adults hospitalized after injury

BACKGROUND: Injury is a major cause of death in adults. Although racial disparities in healthcare access and health outcomes are well documented for medical conditions, the influence of race on access to emergent care after injury has received little scrutiny. OBJECTIVES: We sought to determine whether race was associated with risk of in-hospital death after injury. RESEARCH DESIGN: Data from the Healthcare Cost and Utilization Project (1998-2002) were used to estimate multivariate models of in-hospital mortality, controlling for age, race, gender, comorbid conditions, injury severity, primary payer, median income of zip code of residence, and hospital type. Additional multivariate models were estimated among stratified subsets of patients, including injury severity and hospital type. SUBJECTS: Patients age 18-64 with a primary diagnosis of injury. RESULTS: Relative to injured white patients, black and Asian patients had a higher risk of death [1.5% vs. 2.1% and 2.0%, multivariate odds ratios (OR) = 1.14 and 1.39]. Other racial/ethnic groups showed no significant mortality difference from white patients. In stratified analyses, we found large black-white mortality disparities among mild to moderately injured patients (OR = 1.40, 95% confidence interval: 1.18-1.66), whereas Asian-white disparities were concentrated among more severely injured patients (OR = 1.37, 95% confidence interval: 1.03-1.80). CONCLUSIONS: Black and Asian patients have a higher risk of death after injury than white patients. These data raise important questions about access to quality trauma care for racial minority patients.     

Racial Disparities in Emergency Department Length of Stay for Admitted Patients in the United States

Objectives: Recent studies have demonstrated the adverse effects of prolonged emergency department (ED) boarding times on outcomes. The authors sought to examine racial disparities across U.S. hospitals in ED length of stay (LOS) for admitted patients, which may serve as a proxy for boarding time in data sets where the actual time of admission is unavailable. Specifically, the study estimated both the within‐ and among‐hospital effects of black versus non–black race on LOS for admitted patients. Methods: The authors studied 14,516 intensive care unit (ICU) and non‐ICU admissions in 408 EDs in the National Hospital Ambulatory Medical Care Survey (NHAMCS; 2003–2005). The main outcomes were ED LOS (triage to transfer to inpatient bed) and proportion of patients with prolonged LOS (>6 hours). The effects of black versus non–black race on LOS were decomposed to distinguish racial disparities between patients at the same hospital (within‐hospital component) and between hospitals that serve higher proportions of black patients (among‐hospital component). Results: In the unadjusted analyses, ED LOS was significantly longer for black patients admitted to ICU beds (367 minutes vs. 290 minutes) and non‐ICU beds (397 minutes vs. 345 minutes). For admissions to ICU beds, the within‐hospital estimates suggested that blacks were at higher risk for ED LOS of >6 hours (odds ratio [OR] = 1.42, 95% confidence interval [CI] = 1.01 to 2.01), while the among‐hospital differences were not significant (OR = 1.08 for each 10% increase in the proportion of black patients, 95% CI = 0.96 to 1.23). By contrast, for non‐ICU admissions, the within‐hospital racial disparities were not significant (OR = 1.12, 95% CI = 0.94 to 1.23), but the among‐hospital differences were significant (OR = 1.13, 95% CI = 1.04 to 1.22) per 10% point increase in the percentage of blacks admitted to a hospital. Conclusions: Black patients who are admitted to the hospital through the ED have longer ED LOS compared to non–blacks, indicating that racial disparities may exist across U.S. hospitals. The disparity for non‐ICU patients might be accounted for by among‐hospital differences, where hospitals with a higher proportion of blacks have longer waits. The disparity for ICU patients is better explained by within‐hospital differences, where blacks have longer wait times than non–blacks in the same hospital. However, there may be additional unmeasured clinical or socioeconomic factors that explain these results.     

Can ruptured appendicitis be detected preoperatively in the ED?

PURPOSE: The purpose of this study is to determine which clinical symptoms/signs and computed tomography (CT) signs can help in distinguishing ruptured from simple appendicitis. MATERIALS AND METHODS: The medical records and CT findings of 202 consecutive patients with surgically proven acute appendicitis were retrospectively reviewed and compared between 2 groups with and without appendiceal rupture. RESULTS: Longer duration of symptoms ( P < .001), peritoneal sign ( P = .004), and higher C-reactive protein ( P < .001) are significant clinical factors for predicting appendiceal rupture in acute appendicitis. Abscess, extraluminal air, wall defect, peritoneal enhancement, extraluminal appendolith, phlegmon, localized fluid, fascial thickening, ascites, stool impaction, and 4 patterns of bowel wall thickening ( P < .001 to P = .047) are significant CT signs for predicting appendiceal rupture. The appendiceal diameter is larger in patients with ruptured appendicitis than in those with simple appendicitis (13.2 +/- 3.2 vs 11.3 +/- 2.4 mm, P < .001). The appendolith size is larger in patients with ruptured appendicitis than in those with simple appendicitis (7.1 +/- 4.4 vs 5.1 +/- 2.8 mm, P = .018). CONCLUSION: Besides some clinical findings, CT scan can accurately determine appendiceal rupture in acute appendicitis and can further demonstrate the presence of local inflammatory mass, facilitating management decision in the emergency department (ED).     

Racial disparities in outcomes of persons with moderate to severe traumatic brain injury

BACKGROUND: Although racial differences in hospital outcomes are well known for medical conditions (eg, cardiovascular disease), it is unknown whether differences exist for patients with traumatic brain injury (TBI). RESEARCH DESIGN: Using the National Trauma Data Bank, we examined racial and ethnic differences in hospital outcomes of 56,482 patients with moderate to severe TBI who were hospitalized in level I or II trauma-designated hospitals between 2000 and 2003. We examined racial and ethnic disparities in in-hospital mortality and the likelihood of survivors receiving postacute care at a rehabilitation center. RESULTS: After multivariable adjustment, compared with whites, we observed increased in-hospital mortality for blacks (odds ratio [OR] = 1.19, P = 0.026) and Asians (OR = 1.41, P = 0.005). We observed a trend toward significance for Hispanics (OR = 1.41, P = 0.077), but not for other races. For survivors, compared with whites, blacks and Hispanics were less likely to be discharged to a rehabilitation center (OR = 0.68, P < 0.001, and OR = 0.67, P = 0.002, respectively). CONCLUSIONS: Racial and ethnic disparities exist both in mortality and in discharge to postacute rehabilitation centers among persons with TBI.     

Ethnic/racial disparities in hospital procedure volume for lung resection for lung cancer

BACKGROUND: Ethnic/racial minorities experience poorer outcomes from lung cancer than non-Hispanic whites. Higher hospital procedure volume is associated with better survival from lung resection for lung cancer. OBJECTIVES: We examined whether (1) ethnic/racial minorities are more likely to obtain lung resections at lower volume hospitals, (2) ethnicity/race is associated with inpatient mortality, (3) hospital volume mediates this association, and (4) hospital selection is mediated by racial/ethnic segregation, differences in insurance coverage, or limited hospital choice. METHODS: Six years of data from the Nationwide Inpatient Sample (NIS 1998-2003, unweighted n = 50,245, weighted n = 129,506) were used in multivariate models controlling for sociodemographic factors, case complexity, and hospital characteristics. Additional analyses were conducted using the Area Resource File, which provided data on ethnic density and number of surgical hospitals in the hospital region. RESULTS: Blacks/African Americans (odds ratio [OR] = 0.45; 0.34-0.58) and Latinos (OR = 0.44; 0.32-0.63) had lower odds of obtaining lung resection at a high-volume hospital than non-Hispanic whites. Blacks/African Americans (OR = 1.30; 1.01-1.67), Latinos (OR = 1.41; 1.02-1.94), and other racial/ethnic minorities (OR = 1.46; 1.04-2.06) also had higher odds of dying in hospital, but this association was statistically nonsignificant after controlling for hospital volume. Hospital location was not associated with lung resection procedure volume, nor did location mediate the association between ethnicity/race and hospital volume. CONCLUSIONS: Ethnic/racial minorities are obtaining lung resection in lower volume hospitals and are more likely to die in hospital. Hospital volume is associated with higher mortality, but health insurance, segregation, and number of surgical hospitals within a county do not account for observed disparities.     

Health Care Disparities in Emergency Medicine

The Institute of Medicine's landmark report, "Unequal Treatment: Confronting Racial and Ethnic Disparities in Health Care," documents the pervasiveness of racial and ethnic disparities in the U.S. health care delivery system, and provides several recommendations to address them. It is clear from research data, such as those demonstrating racial and ethnic disparities in emergency department (ED) pain management, that emergency medicine (EM) is not immune to this problem. The IOM authors describe two strategies that can reduce disparities in EM. First, workforce diversity is likely to result in a community of emergency physicians who are better prepared to understand, learn from, and collaborate with persons from other racial, ethnic, and cultural backgrounds, whether these be patients, fellow clinicians, or the larger medical and scientific community. Given the ethical and practical advantages of a more diverse EM workforce, continued and expanded initiatives to increase diversity within EM should be undertaken. Second, the specialty's educational programs should produce emergency physicians with the skills and knowledge needed to serve an increasingly diverse population. This cultural competence should include an awareness of existing racial and ethnic health disparities, recognition of the risks of stereotyping and biased treatment, and knowledge of the incidence and prevalence of health conditions among diverse populations. Culturally competent emergency care providers also possess the skills to identify and manage racial and ethnic differences in health values, beliefs, and behaviors with the ultimate goal of delivering quality health services to all patients cared for in EDs.     

Experience of primary care by racial and ethnic groups in the United States.

OBJECTIVES: The purpose of this study was to examine the experience of primary care by racial and ethnic groups and identify aspects of primary care where significant disparities in experience exist across racial and ethnic groups. METHODS: Data for this study came from the Household Component of the 1997-1998 Medical Expenditure Panel Survey (MEPS), a nationally representative survey of the civilian noninstitutionalized population of the United States. Measures were identified within MEPS that denote race, ethnicity, experience of primary care, and socioeconomic covariates associated with access to care. RESULTS: Racial and ethnic minorities experienced worse primary care, particularly in the first-contact aspect, than did white Americans. Their usual sources of care were more likely to be hospital settings than private clinics. They faced greater barriers accessing their usual source of care (USC), finding it more difficult to get an appointment and waiting longer during an appointment. Many of the significant differences persist after adjustment for sociodemographic and health-status characteristics. CONCLUSIONS: Racial and ethnic disparity in primary care experience is not simply a reflection of sociodemographic and health-status differences across racial/ethnic groups. Efforts must be made to reduce nonfinancial as well as financial barriers to care and ensure that quality primary care is provided in all settings, public as well as private, and to individuals of all colors.     

Racial Disparities in Total Joint Arthroplasty

Purpose of ReviewThe primary aim of this review was to evaluate recently published total joint arthroplasty (TJA) studies in order to accurately summarize the current concepts regarding racial and ethnic disparities in total joint arthroplasty.Recent FindingsMany studies found that racial and ethnic disparities in TJA are present in all phases of arthroplasty care including access to, utilization of, and postoperative outcomes after TJA.SummaryFactors that limit patient access to TJA—increased patient comorbidities, lower socioeconomic status, and Medicaid/uninsured status—are also disproportionately associated with underrepresented patient populations. Minority patients are more likely to require more intensive postoperative rehabilitation and non-home discharge placement. This in turn potentially adds additional concerns regarding hospital/provider reimbursement in light of the current Medicare/Medicaid model for arthroplasty surgeons, thus creating a recurrent cycle in which disparities in TJA reflect the complex interplay of overall health disparities and access inequalities associated with racial and ethnic biases. Literature demonstrating evidenced-based interventions to minimize these disparities is sparse, but the multifactorial cause of disparities in TJA highlights the need for multifaceted solutions on both a systemic and individual level.     

Technology diffusion, hospital variation, and racial disparities among elderly Medicare beneficiaries: 1989-2000

BACKGROUND: Low rates of technology utilization in hospitals with high proportions of black inpatients may be a remediable cause of healthcare disparities. OBJECTIVES: Our objective was to determine how differences in technology utilization among hospitals contributed to racial disparity and if temporal reduction in hospital procedure rate variation resulted in decreased racial disparity for these technologies. METHODS: We identified 2,348,952 elderly Medicare beneficiaries potentially eligible for 1 of 5 emerging medical technologies from 1989-2000 and determined if these patients had received the indicated procedure within 90 days of their qualifying hospital admission. Initial multivariate regression models adjusted for age, race, sex, admission year, clinical comorbidity, community levels of education and income, and academic/urban hospital admission. The inpatient racial composition of each patient's admitting hospital and time-race interactions were added as covariates to subsequent models. RESULTS: Blacks had significantly lower adjusted rates (P < 0.001) compared with whites for tissue replacement of the aortic valve, internal mammary artery coronary bypass grafting, dual-chambered pacemaker implantation, and lumbar spinal fusion. Hospitals with > 20% black inpatients were less likely to perform these procedures on both white and black patients than hospitals with < 9% black inpatients, and racial disparity was greater in hospitals with larger black populations. There were no temporal reductions in racial disparities. CONCLUSIONS: Blacks may be disadvantaged in access to new procedures by receiving care at hospitals that have both lower procedure rates and greater racial disparity. Policies designed to ameliorate racial disparities in health care must address hospital variation in the provision of care.     

Race/Ethnic and Stroke Subtype Differences in Poststroke Functional Recovery After Acute Rehabilitation

ObjectiveSignificant racial/ethnic disparities in poststroke function exist, but whether these disparities vary by stroke subtype is unknown. Study goals were to (1) determine if racial/ethnic disparities in the recovery of poststroke function varied by stroke subtype and (2) identify confounding factors associated with these racial/ethnic disparities.DesignSecondary analysis of the 1-year Stroke Recovery in Underserved Populations Cohort Study.SettingEleven inpatient rehabilitation facilities (IRFs) across the United States.ParticipantsA total of 1066 patients (n=868 with ischemic stroke and n=198 with hemorrhagic stroke, N=1066) who self-identified as White (n=813), Black (n=183), or Hispanic (n=70).InterventionsNot applicable.Main Outcome MeasuresFIM scores at IRF admission, discharge, 3 months, and 12 months were modeled using multivariable mixed effects longitudinal regression.ResultsCompared with White patients, Black (−6.1 and −4.6) and Hispanic (−10.1 and −9.9) patients had significantly lower FIM scores at 3 and 12 months, respectively. A significant (P<.01) 3-way interaction (race/ethnic*subtype*time) indicated that disparities varied by stroke subtype. The stroke subtype differences were most prominent for Black-White disparities because disparities in hemorrhagic stroke were present at IRF admission (vs 3 months for ischemic stroke). Additionally, at 12 months, the magnitude of Black-White disparities was over 3 times larger for hemorrhagic stroke (−10.4) than ischemic stroke (−3.1). Age primarily influenced Black-White disparities (especially for hemorrhagic stroke), but factors that influenced Hispanic-White disparities were not identified. Sensitivity analyses showed that there were stroke subtype differences in racial/ethnic disparities for cognitive (but not motor) function, and results were robust to adjustments for missing data because of attrition.ConclusionsThere are significant differences between stroke subtypes in the timing and magnitude of Black-White disparities in poststroke function. Age was a major confounding factor for Black-White disparities (particularly for hemorrhagic stroke). Overall, Hispanic patients had the lowest levels of poststroke function, and more work is needed to identify significant factors that influence Hispanic-White disparities.     

Racial and ethnic disparities in the emergency department: a public health perspective

This article discusses racial and ethnic disparities from a public health perspective, specifically why they threaten to impede the efforts to improve the nation's health. The authors (1) provide background information, including a review of the Institute of Medicine report on health care disparities; (2) describe the racial and ethnic compositions of the individuals in the emergency department setting from the perspective of both the patient and health care provider; (3) discuss the most prevalent disease presentations to the emergency department that are likely to have racial and ethnic disparities; and (4) give conclusions and general recommendations on how to address disparities in emergency health care.     

How scholarly nursing literature addresses health disparities for racial/ethnic minority men.

The purpose of this article is to review conceptual/theoretical and review/agenda setting nursing literature on the health care of racial/ethnic minority men [specifically African American/Black, Hispanic/Latino, American Indian/Alaskan Native and Asian/Pacific Islander men] in one of the four targeted areas of health disparities. CINAHL and MEDLINE computer databases were searched from 1983 to the present using a combination of manual and computer-based methods to identify the nursing literature that included any racial/ethnic men in the sample and addressed at least one of the four areas of health disparities targeted by Department of Health and Human Services (DHHS) that affect adults: heart disease, malignant neoplasms (cancer), diabetes mellitus and Human Immunodeficiency Virus (HIV)/AIDS. This review provides an overview of health disparities experienced by racial/ethnic minority men in the targeted areas and of the types of conceptual and agenda-setting articles published in scholarly nursing literature in those targeted areas.     

Emergency Medical Practice: Advancing Cultural Competence and Reducing Health Care Disparities

In an increasingly diverse patient population, language differences, socioeconomic circumstances, religious values, and cultural practices may present barriers to the delivery of quality care. These obstacles contribute to the health care disparities observed in all areas of medical care. Increasing cultural competence has been cited as part of the solution to reduce disparities. The emergency department (ED) is an environment where cultural sensitivity is particularly needed, as it is often a primary source of health care for the underserved and ethnic and racial minorities and a place where high patient volume and acuity place the provider under demanding time pressures, yet the emergency medicine (EM) literature on health care disparities and cultural competence is limited.
The authors present three clinical scenarios highlighting challenges in providing equitable emergency care to minority populations. Using these cases as illustrations, three processes are proposed that may improve the quality of care delivered to minority populations: 1) increase cultural awareness and reduce provider biases, enabling providers to interact more effectively with different patient populations; 2) accommodate patient preferences and needs in medical settings through practice adjustments and cultural modifications; and 3) increase provider diversity to raise levels of tolerance, awareness, and understanding for other cultures and create more racially and/or ethnically concordant patient–physician relationships.     

Disparities in utilization of coronary artery disease treatment by gender, race, and ethnicity: opportunities for prevention.

Racial, ethnic, (R/E) and gender disparities in access to health services in the United States and their relationship to adverse health outcomes are well established. Despite an increase in evidence-based cardiovascular treatment, gender, racial, and ethnic disparities in coronary artery disease (CAD) treatment persist. There is neither currently a comprehensive framework for understanding why disparities occur in cardiovascular disease care, nor viable solutions for intervention. This article synthesizes the literature on disparities in coronary artery disease with a conceptual model for understanding chronic disease disparities. This article follows the natural history of disease to observe where differences arise, beginning with health risk management, screening, diagnosis, treatment, and rehabilitation. Racial, ethnic, and gender differences were found at every step of this continuum, including a higher burden of risk factors and a less likelihood of receiving needed lifesaving cardiac procedures. Unfortunately, there is a dearth of intervention strategies to reduce racial, ethnic, and gender disparities in coronary artery disease. Comprehensive solutions will require addressing the barriers at the system, the provider, and the patient level. An early intervention approach that addresses multiple risk factors should be a high priority.     

Racial/ethnic differences in poststroke rehabilitation utilization in the USA

Longstanding racial/ethnic disparities exist in the USA in the areas of healthcare access, healthcare utilization and health-related outcomes of chronic health conditions, such as stroke. Regarding stroke specifically, significant racial/ethnic disparities in stroke incidence, severity and outcomes have been reported. Despite these differences, little attention has been given to potential racial/ethnic differences in the utilization of rehabilitation services for patients after stroke. To date, only a few studies have been specifically designed to examine racial/ethnic differences in rehabilitation service utilization. A review of these studies and related studies suggests that racial/ethnic differences may be present in the utilization of poststroke rehabilitation services. Consequently, new studies are needed to delineate how race/ethnicity influences utilization of poststroke rehabilitation services and to determine how a reduction in this disparity gap could improve stroke-related outcomes among racial/ethnic minorities in the USA.     

Ethnic differences in cardiovascular risks and mortality in atherothrombotic disease: insights from the Reduction of Atherothrombosis for Continued Health (REACH) registry

OBJECTIVETo determine whether ethnic-specific differences in the prevalence of cardiovascular risk factors and outcomes exist worldwide among individuals with stable arterial disease.PATIENTS AND METHODSFrom December 1, 2003, to June 30, 2004, the prospective, observational REduction of Atherothrombosis for Continued Health (REACH) Registry enrolled 49,602 outpatients with coronary artery disease, cerebrovascular disease, and/or peripheral arterial disease from 7 predefined ethnic/racial groups: white, Hispanic, East Asian, South Asian, Other Asian, black, and Other (comprising any race distinct from those specified). The baseline demographic and risk factor profiles, medication use, and 2-year cardiovascular outcomes were assessed among these groups.RESULTSThe prevalence of traditional atherothrombotic risk factors varied significantly among the ethnic/racial groups. The use of medical therapies to reduce risk was comparable among all groups. At 2-year follow-up, the rate of cardiovascular death was significantly higher in blacks (6.1%) compared with all other ethnic/racial groups (3.9%; P=.01). Cardiovascular death rates were significantly lower in all 3 Asian ethnic/racial groups (overall, 2.1%) compared with the other groups (4.5%; P<.001).CONCLUSIONThe REACH Registry, a large international study of individuals with atherothrombotic disease, documents the important ethnic-specific differences in cardiovascular risk factors and variations in cardiovascular mortality that currently exist worldwide.     

Lack of Association between Patient Ethnicity or Race and Fracture Analgesia

OBJECTIVE: Ethnic and racial differences in the provision of emergency department (ED) analgesia for long-bone fractures have recently been reported in two large cities. The authors sought to determine, in a third city, whether nonwhite patients with long-bone fractures were less likely to receive analgesics than white patients with similar injuries. METHODS: At an urban Level 1 trauma center and teaching hospital, a retrospective cohort study was conducted of all ED patients aged 18 to 55 years seen from July 1, 1998, through June 30, 1999, with an ED discharge diagnosis of isolated long-bone fracture identified by ICD-9 codes 812, 813, 821, and 823. Exclusion criteria included injury more than 12 hours prior to presentation or a Glasgow Coma Scale score of less than 14. The main outcome measure was ED analgesia administration. RESULTS: Three hundred twenty-three patients met inclusion criteria; 181 were white, 58 African American, 46 Hispanic, 38 Asian. All ethnic/racial groups were equally likely to receive no analgesia or no parenteral analgesia. The overall risk for no analgesia was 20% and for no parenteral analgesia was 31%. Stratification and multiple logistic regression to control for gender, bone fractured, and need for reduction failed to identify any trend toward reduced analgesia administration in any ethnic/racial group. CONCLUSIONS: In contrast to two recently reported studies, at this urban trauma center and teaching hospital ED, there was no difference in the administration of analgesics to white and nonwhite patients with long-bone fractures.     

Appendiceal enlargement as a criterion for clinical diagnosis of acute appendicitis: is it reliable and valid?

The purpose of this study was to evaluate appendiceal enlargement as a radiographic criterion for the diagnosis of acute appendicitis. We examined medical records and specimens of 190 adults and children who presented to a teaching hospital in New York City with right-lower-quadrant pain and who underwent surgery. Computed tomography (CT), clinical evaluation (based on Alvarado's predictive model) and pathologic data of these 190 cases revealed that appendiceal enlargement might in some cases represent a normal anatomic variant of a vermiform appendix and that the lack of a dilated lumen and thickened wall did not necessarily establish the absence of inflammation. Yet, radiologic evidence of appendix size often influences the diagnosis and management of patients with acute abdominal pain, including the decision to operate. This tendency to equate an enlarged appendix with appendicitis is shown to lead to an inappropriate diagnosis and jeopardize optimal care of patients with acute abdominal pain.