P0557 VALIDATION OF A CLINICAL CASE DEFINITION FOR THE DIAGNOSIS OF ACUTE INTUSSUSCEPTION IN A DEVELOPED AND DEVELOPING COUNTRY

Abstract

Introduction: A clinical case definition (CCD) for acute intussusception (IS) in infants and children has been developed by WHO and the Brighton Collaboration to establish practical clinical criteria to identify the majority of patients with IS (1,2). Not only will this enable prompt identification of infants with IS to reduce morbidity associated with IS, but will also provide an important tool for future clinical trials of oral vaccines. This study aims to validate the CCD for IS in both developed (Australia) and developing (Vietnam) countries. Methods: The sensitivity of the CCD was prospectively assessed in patients <2 years of age with IS proven by air enema or surgery, over a 20 month period at the Royal Children’s Hospital(RCH), Melbourne and 12 month period at the National Hospital of Paediatrics (NHP), Hanoi. The assessing doctor completed a standardised questionnaire itemising the symptoms/signs of each case. Each patient was then categorised as having probable, possible or negative IS according to the levels of diagnostic certainty defined in the CCD. The specificity of the CCD was assessed in patients <2 years presenting to the emergency room of both hospitals with symptoms/signs consistent with IS, but in whom an alternative diagnosis was established. Results: During the 12 month study period at NHP, 489 IS patients were diagnosed with IS compared with 41 cases during 20 month study at RCH. The sensitivity of the CCD in the detection of IS in patients with proven IS was 98% at RCH (“probable” 39/41) and 96% at NHP (“probable” 400/417: 72/489 unable to be assessed due to insufficient data). The specificity of the CCD in correctly identifying the patients as not having IS was 92% (48/52 assessable patients) at NHP and 86% at RCH. Conclusion: The clinical case definition was both sensitive and specific for the diagnosis of acute IS in both a developed and developing country.