Accuracy of diagnostic tests for acute diverticulitis that are feasible in primary care: a systematic review and meta-analysis

Background: Recognition of acute diverticulitis is important to determine an adequate management strategy. Differentiating it from other gastrointestinal disorders is challenging as symptoms overlap. Clinical tests might assist the clinician with this diagnostic challenge. Previous reviews have focussed on prognostic questions and imaging examinations in secondary care. Objective: To evaluate the diagnostic accuracy of clinical tests feasible in primary care for acute diverticulitis in suspected patients. Method: We have systematically searched multiple databases for diagnostic accuracy studies of tests feasible in primary care compared to a reference standard in suspected patients. Two reviewers independently selected studies, extracted data, and assessed study quality with the QUADAS-2 tool. We have meta-analysed the results in the case of more than four studies per index test. Results: Seventeen studies were included, all studies were performed in secondary care (median prevalence 48%). Individual signs and symptoms showed a wide range in sensitivity (range 0.00-0.98) and specificity (range 0.08-1.00). Of the four laboratory tests evaluated, CRP >10 mg/l had the highest sensitivity (range 0.89-0.96) with specificity ranging from 0.28 to 0.61. Ultrasound had the highest pooled sensitivity and specificity of 0.92 (95% CI 0.86-0.96) and 0.94 (95% CI 0.88-0.97), respectively. Conclusion: None of the studies were performed in primary care. Individual signs and symptoms alone are insufficiently informative for acute diverticulitis diagnosis. CRP showed potential for ruling out and ultrasound had a high diagnostic accuracy. More research is needed about the diagnostic accuracy of these tests in primary care. PROSPERO registration number CRD42021230622