Treatment options for patients with pilonidal sinus disease: PITSTOP, a mixed-methods evaluation

Background There is no consensus on optimal management of pilonidal disease. Surgical practice is varied, and existing literature is mainly single-centre cohort studies of varied disease severity, interventions and outcome assessments. Objectives A prospective cohort study to determine: disease severity and intervention relationship most valued outcomes and treatment preference by patients recommendations for policy and future research. Design Observational cohort study with nested mixed-methods case study. Discrete choice experiment. Clinician survey. Three-stage Delphi survey for patients and clinicians. Inter-rater reliability of classification system. Setting Thirty-one National Health Service trusts. Participants Patients aged > 16 years referred for elective surgical treatment of pilonidal disease. Interventions Surgery. Main outcome measures Pain postoperative days 1 and 7, time to healing and return to normal activities, complications, recurrence. Outcomes compared between major and minor procedures using regression modelling, propensity score-based approaches and augmented inverse probability weighting to account for measured potential confounding features. Results Clinician survey: There was significant heterogeneity in surgeon practice preference. Limited training opportunities may impede efforts to improve practice. Cohort study: Over half of patients (60%; N = 667) had a major procedure. For these procedures, pain was greater on day 1 and day 7 (mean difference day 1 pain 1.58 points, 95% confidence interval 1.14 to 2.01 points, n = 536; mean difference day 7 pain 1.53 points, 95% confidence interval 1.12 to 1.95 points, n = 512). There were higher complication rates (adjusted risk difference 17.5%, 95% confidence interval 9.1 to 25.9%, n = 579), lower recurrence (adjusted risk difference −10.1%, 95% confidence interval −18.1 to −2.1%, n = 575), and longer time to healing (>34 days estimated difference) and time to return to normal activities (difference 25.9 days, 95% confidence interval 18.4 to 33.4 days). Mixed-methods analysis: Patient decision-making was influenced by prior experience of disease and anticipated recovery time. The burden involved in wound care and the gap between expected and actual time for recovery were the principal reasons given for decision regret. Discrete choice experiment: The strongest predictors of patient treatment choice were risk of infection/persistence (attribute importance 70%), and shorter recovery time (a