Patient and Healthcare Provider Characteristics Associated with Obtaining Abdominal CT scans to Evaluate Diarrhea in United States Emergency Departments (NHAMCS-ED 2016-2018)

Abstract

Abstract Background: Adults with diarrhea are frequently evaluated in emergency departments (EDs) in the United States (US). Abdominal/pelvic CT can be helpful in the exploration of intra-abdominal pathologies that require more extensive management than ordinary diarrheal illnesses. We investigated abdominal/pelvic CT usage frequency for adult patient ED diarrhea visits and identified factors associated with ordering these scans.

Methods: We conducted an analysis of the National Hospital Ambulatory Medical Care Survey (NHAMCS-ED) (2016-2018) for patients ≥ 18 years old presenting with diarrhea. We created logistic regression models to identify patient and healthcare provider factors associated with abdominal/pelvic CT usage.

Results: Of the 319,404,732 million visits to US EDs from 2016 to 2018, diarrhea counted for 10,391,317 visits (3.2%), of which 32% (3,334,043 visits) included abdominal/pelvic CT scanning. In the multivariable analysis, patients 38-77 years old, visits involving an ED attending physician only, and the presence of abdominal pain were associated with greater CT utilization.

Conclusions: Almost one-third of US ED adult visits for diarrhea included an abdominal/pelvic CT scan, although utilization was more frequent based on age, presence of abdominal pain, and if an ED attending physician was the sole medical provider for the visit. More studies are needed to determine if this level of CT utilization and if variations in usage are appropriate for this presenting complaint. Keywords: Diarrhea, Adults, Abdominal/pelvic CT, Emergency department (ED), National Hospital Ambulatory Medical Care Survey, NHAMC, United States (US). Abstract Introduction: Diarrhea can be a challenging emergency department (ED) presentation because differential diagnoses range from simple low-risk conditions to life-threatening diseases. In addition to obtaining the medical history and performing the clinical examination, ED evaluations for adults with diarrhea include laboratory testing and radiographic imaging to help discern specific diagnoses. In this study, we addressed gaps in knowledge on the frequency and trends of laboratory testing (metabolic panels, CBC, blood cultures) and radiologic imaging (abdominal/pelvic CT scans) are obtained, IVFs and empiric antibiotics are administered, and patients are admitted to the hospital among adults presenting to US EDs with diarrhea. Methods: This is a retrospective secondary analysis study. We included all EDs visits with diarrhea ≥ 18 years old in the National Hospital Ambulatory Medical Care Survey (NHAMCS 2016-2018). We stratified the visits into six age groups. We created a multivariable logistic regression model adjusting for probable and available covariates. Results: Across all age groups, the adjusted proportions of usage of these services were as follows: CBC 78.9% (95% CI 74.9-82.4), blood culture 5.5% (95% CI 3.9-7.8), metabolic panels 75.8% (95% CI 71.1-80), ultrasound 7.2% (95% CI 5.5-9.4), abdominal/pelvic CT scans 29.6% (95% CI 25.5-33.9), IVFs 62.3% (95% CI 57.8-66.5), empiric antibiotics 3.3% (95% CI 2-5.3), hospital admission 11.1% (95% CI 8.4-14.4). ED patients ≥ 65 years old were more likely than those 18-24 years old to receive empiric antibiotics during their ED stay, undergo abdominal/pelvic CT scanning, and be admitted to the hospital. Conclusion: Our study shows that CBC and metabolic panels were obtained, and IVFs administered commonly obtained for adult patients with diarrhea who visited US EDs during 2016 through 2018. However, utilization of blood cultures, ultrasound, and empiric antibiotics, and hospital admission were not common. Only empiric antibiotic administration and hospital admission were greater among visits by patients ≥65 years old, as compared to younger patients.

Keywords: Emergency department, National Hospital Ambulatory Medical Care Survey-Emergency Departments, NHAMCS, Diarrhea, Abdominal/pelvic CT, ultrasound, CBC, Blood culture, Electrolytes, Empiric antibiotics, IV fluids, hospital admission, the United States (US).