Appropriate use of colonoscopy in Nigeria: a retrospective study using the American Society of Gastrointestinal Endoscopy (ASGE) 2012 guidelines

INTRODUCTION: Colonoscopy is the standard investigation for assessing colonic disease, with moderate yield. The American Society for Gastrointestinal Endoscopy (ASGE) published guidelines to tailor the appropriate use of colonoscopy. The aims of this study were to determine the frequency at which colonoscopy was performed for an appropriate indication based on ASGE´s 2012 guidelines, and to determine if there was an association of appropriateness of indication with endoscopic findings. METHODS: a retrospective study of colonoscopies performed in a private endoscopy centre in Lagos, Nigeria, between January 2014 and December 2016. Ethical approval was obtained before commencement. Data retrieved were basic demographics, indication of, and findings at colonoscopy. Data were analysed using SPSS 23. A p-value of <0.05 was considered significant. RESULTS: altogether 627 colonoscopies were performed, 464 (74%) were male, mean age was 53.6 (± 14.3) years, 255 (40.7%) were younger than 50 years. Colonoscopy was appropriately indicated in 450 (71.8%). Women were nearly twice as likely to have an unnecessary procedure than men. The overall diagnostic yield of 39.6% was similar in appropriately (41.6%) and inappropriately (34.5.%) indicated procedures. Older age, abdominal mass on imaging or examination, unexplained weight loss and chronic constipation were independently associated with diagnostic yield. The pooled sensitivity and specificity of the ASGE guidelines for significant endoscopy findings were 75%, and 31% respectively. CONCLUSION: there was a high rate of unnecessary colonoscopies, especially in women. Older patients, and those with chronic constipation, unexplained weight loss and an abdominal mass, should be referred for urgent colonoscopy.