Prespecified Internal Pilot and Feasibility Framework for a Pragmatic Randomized Controlled Trial Comparing Mechanical Diagnosis and Therapy Versus Generalized Exercise in Surgeons With Chronic Spinal Pain: A Protocol

Background Trials in occupational populations, such as surgeons, face feasibility challenges due to high workload, restricted availability, and clinical heterogeneity, which may compromise recruitment, adherence, and retention. Objective To prespecify the feasibility framework and progression criteria for an internal pilot phase embedded within a pragmatic randomized controlled trial (RCT) comparing Mechanical Diagnosis and Therapy with generalized exercise in surgeons with chronic spinal pain. Design Protocol for a prespecified internal pilot phase embedded within a pragmatic, two-arm, parallel-group RCT. Methods The internal pilot will include the first four months of recruitment and aims to randomize at least 12 participants. Feasibility will be assessed across predefined domains, i.e., recruitment, eligibility, consent, intervention uptake, adherence, retention, data completeness, and treatment fidelity. Each domain is operationally defined and linked to prespecified progression criteria to ensure interpretability and decision-making utility. Criteria will be interpreted collectively to guide trial continuation. A minimal qualitative process evaluation will be embedded. Ethics and dissemination The host trial has received ethical approval (N-20240046) and is registered at ClinicalTrials.gov (NCT07293130). The findings from the internal pilot will be reported in a separate feasibility manuscript.