The Songdo consensus: Development of minimum reporting standards for studies of intervention in idiopathic anal fistula using a modified nominal group technique.

Aim: Cryptoglandular anal fistulas carry a substantial burden to quality of life. Surgery is the only effective curative treatment but requires balancing fistula healing against pain, wounds and continence impairment. Sphincter-preserving procedures do exist but demonstrate variable rates of success. A lack of consistency and precision in outcome reporting and methodological quality hinders effective evidence-based decision-making. We aimed to establish a series of minimum reporting standards for interventional studies in idiopathic anal fistula, to eradicate low-quality studies, thus providing a consistent baseline of useful evidence.

Methods: An international group of 16 experts participated in a modified nominal group technique consensus. The nominal question was: 'What should be the minimum set of reporting standards for studies of intervention in idiopathic anal fistula?' The process was conducted between May and June 2023, culminating in a hybrid in-person/virtual meeting that took place at the Songdo International Proctology Symposium in June 2023.

Results: Initial idea generation resulted in 37 statements within the first round. Themes included variable reporting of follow-up and incontinence. Participants indicated their agreement via a 9-point Likert scale. Any statement achieving >70% consensus was retained. Subsequent group discussion condensed the list to 11 statements for further voting and a final minimum set of 12 reporting standards was created.

Conclusion: To date, this is the first study dedicated to developing minimum reporting standards for interventional studies in idiopathic anal fistula using a modified nominal group technique. These standards will instruct researchers in producing meticulous, high-quality studies that are accurate, transparent and reproducible.