Trends in visits, imaging, and diagnosis for emergency department abdominal pain presentations in the United States, 2007-2019

Objectives: Abdominal pain is the most common reason for visit (RFV) to the emergency department (ED) for adults, yet no standardized diagnostic pathway exists for abdominal pain. Optimal management is age-specific; symptoms, diagnoses, and prognoses differ between young and old adults. Availability and knowledge of the effectiveness of various imaging modalities have also changed over time. We compared diagnostic imaging rates for younger versus older adults to identify practice patterns of abdominal imaging across age groups over time. Methods: We analyzed weighted, nationally representative data from the National Hospital Ambulatory Medical Care Survey 2007-2019 for adult ED visits with a primary RFV of abdominal pain. We included 23,364 sampled visits, representing 123 million visits. Results: From 2007 to 2019, total visits increased for ages 18-45 (p < 0.001), 46-64 (p < 0.001), and 65+ (p = 0.032). The percentage of visits with primary RFV of abdominal pain increased from 9.4% to 11.6% for ages 18-45, 7.8%-9.0% for ages 46-64, and 6.0%-6.5% for 65+. Computed tomography (CT) scan rates increased over time from 26.2% of all patients receiving a CT scan to 42.6%. Relative percentage change in abdominal CT scans was greatest for older adults, with a 30.3% increase, compared to 24.0% for middle-aged adults and 15.0% for young adults. Test positivity, defined as receiving an emergency general surgical diagnosis after CT or ultrasound, increased from 17.2% in 2007 to 22.9% in 2019 (p < 0.01). Of the older adults with abdominal pain in 2019, 13% received an X-ray only, which is neither sensitive nor specific for acute pathology in older adults. Conclusions: Despite more abdominal pain ED visits and increased imaging rates per visit, test positivity continues to rise. Our findings do not support claims that CT and ultrasound are being used less appropriately over time, but demonstrate widespread use of X-rays, which are potentially ineffective for abdominal pain.