Anorectal malformation and outcome review (ARMOUR) project: a systematic review for the outcomes reported in patients with an anorectal malformation.

Background: Being born with an anorectal malformation (ARM) often leads to lifelong issues with faecal and urinary function, as well as challenges in sexual, emotional and psychosocial development. Even when anatomical correction is achieved, full functional recovery is not guaranteed. Despite several international consensus meetings with leading medical professionals in the ARM field, there is still no agreement on the essential outcome domains that should be measured for ARM treatment and follow-up. Therefore, the goal of this systematic review is to identify all the outcomes reported in literature.

Methods: This systematic review adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, aiming to identify all short- and long-term outcomes in ARM studies. A literature search was conducted in PubMed and Embase for studies from 1 January 2009 to 1 May 2023, using terms related to 'anorectal malformation'. The Cochrane Library was also searched, but no relevant reviews were found. Eligibility criteria included studies mentioning ARM outcomes in the title or abstract. Exclusions were non-mention of ARM outcomes, lack of full text, and non-English or non-Dutch language. Data extraction by two reviewers captured author details, study design, patient characteristics, ARM types and outcomes, categorised by occurrence time and reporter. Outcomes were consolidated from 339 unique outcomes into 25 domains according to the Core Outcome Measures in Effectiveness Trial () taxonomy and categorised into five core areas: 'mortality/survival', 'physiological/clinical', 'life impact', 'resource use' and 'adverse events'.

Results: Out of 348 eligible studies, 118 met the inclusion criteria. These were mostly conducted in Europe (47%), Asia (34%) and North America (11%), with designs including retrospective (36%), cross-sectional (23%) and case reports/series (18%). Patient numbers ranged from 1 to 1206, with many studies lacking clear descriptions of surgical techniques (29%) and age categories (21%). A total of 339 outcomes were identified, categorised into 25 domains per the COMET taxonomy. Mentioned most frequently were 'physiological/clinical' outcomes (772 mentions), with 'gastrointestinal outcomes' being predominant. Long-term outcomes were most common (71%), followed by both short and long term (16%), and short term (13%). Outcomes were mainly reported by medical professionals (59%), with only 10% being patient-reported outcomes. Various measurement tools were used, including validated and self-made instruments, with the international classification (Krickenbeck) being the most used rating scale for postoperative results. Many studies lacked detailed descriptions and validation of their measurement methods.The identified outcomes in this review will be used as an input to eventually develop a Core Outcome Set.