Comparison of Adenoma Detection Rate (ADR) in Split-Dose Versus Same-Day Colonoscopy Preparation: A Systemic Review and Meta-analysis

Abstract

Introduction: Preparation to colonoscopy (PC) interval has been recently shown to have important impact on colposcopy preparation. A few studies have shown that same day colon preparation is superior to split dose preparation with less adverse effects, better quality of life and superior Ottawa scale scores for quality of colon preparation. However, none of the studies used adenoma detection rate, a bench mark of adequate colonoscopy, as a primary outcome. Some studies have shown superior detection rate in same day preparation whereas others suggest no difference. Our aim was to conduct meta-analysis to see which approach has higher adenoma detection rate and to determine pooled effect size if one or the other approach is better. Methods: We searched Medline, EMBASE, Cochrane database, ISI Web of Science and Scopus from inception through May 2015, to identify prospective and randomized control studies that provided data on adenoma detection rate using morning only compared with split dose preparations for afternoon colonoscopies. After pooling data, a fixed effects meta-analys was performed as there was no significant heterogeneity in study population. Three out of 157 studies were considered in analysis. All included studies reported adenoma detection rate (ADR) as one of the secondary outcomes. Results: Two prospective and one randomized clinical trials were included in the analysis which consisted of a total of 477 patients. The study populations in all three studies were well matched for baseline characteristics. The pooled odds ratio (OR) evaluating the adenoma detection in split dose cohort compared to same day group was 0.68 (95% confidence interval (CI) 0.46 - 1.01. No significant heterogeneity (I2=0) or publication bias were noted. Conclusion: Pooled analysis failed to show statistically significant difference in adenoma detection rate (ADR) between same day or split dose preparations. However, a trend towards higher adenoma detection rate in same day preparation cohort was noted. Our analysis has limitations due to lack of large randomized trials and the fact that half of the pooled effect was contributed by one study. In addition adenoma detection rate was not used as primary outcome in any of the studies published to date. This highlights the need for further trials using ADR as primary outcome before same day preparation can become a standard of care.Figure 1