Management of non-traumatic abdominal pain in the emergency department: a multicentre, stepped-wedge, cluster-randomised trial.

Background: Even though abdominal pain is one of the most frequent chief complaints in emergency medicine, standardized care pathways are still lacking. In this study, a standardized, digitally-supported care pathway for non-traumatic abdominal pain in the emergency department was investigated with regard to emergency department length of treatment, pain score at discharge, and patient satisfaction. Methods: In a prospective mixed-methods, multicentre, cluster-randomised, controlled stepped wedge trial, adult patients with non-traumatic abdominal pain were enrolled in ten emergency departments across Germany. The new care pathway was implemented at randomly assigned time points (every four months) within a 24-month recruitment period and consisted of a structured care pathway for the management of abdominal pain patients in the emergency department. During the control period, the standard treatment for abdominal pain in the emergency department was administered. The planned sample size was 2000. Primary outcomes were: emergency department length of treatment, pain score (numeric rating scale 0-10), and patient satisfaction score at the end of emergency department treatment. Exploratory safety outcomes were serious adverse events within 30 days. Trial registration: DRKS00021052. Findings: Of 2119 patients, 1017 were enrolled in the control group, and 1102 in the intervention group. Crude mean emergency department length of treatment was 5.2 h (±3.0) in the control group, and 4.3 h (±2.2) in the intervention group while the adjusted mean difference was -0.31 h (95% confidence interval (CI) -0.70 to 0.07). Mean pain score was 4.3 (±2.5) in the control group, and 3.6 (±2.4) in the intervention group, resulting in an adjusted mean difference of -0.69 (95% CI -1.04 to -0.34). The adjusted mean difference of patient's satisfaction score was 1.54 (95% CI 0.96 to 2.12); mean control group: 26.7 (±4.0); mean intervention group: 27.9 (±3.8)). Serious adverse events were comparable between both groups while 30-day mortality was 2.3% (n = 23) in the control group, and 0.8% (n = 9) in the intervention group (mean difference: -1.4% (95% CI -2.5 to -0.4)). Interpretation: The APU process is safe and did not increase emergency department length of treatment, while patient-reported outcomes and safety were improved accompanied by an increased use of diagnostic procedures. Funding: The study was funded by the German Innovations Funds.