Stratified primary care versus non-stratified care for musculoskeletal pain: findings from the STarT MSK feasibility and pilot cluster randomized controlled trial

Background Musculoskeletal (MSK) pain from the five most common presentations to primary care (back, neck, shoulder, knee or multi-site pain), where the majority of patients are managed, is a costly global health challenge. At present, first-line decision-making is based on clinical reasoning and stratified models of care have only been tested in patients with low back pain. We therefore, examined the feasibility of; a) a future definitive cluster randomised controlled trial (RCT), and b) General Practitioners (GPs) providing stratified care at the point-of-consultation for these five most common MSK pain presentations. Methods The design was a pragmatic pilot, two parallel-arm (stratified versus non-stratified care), cluster RCT and the setting was 8 UK GP practices (4 intervention, 4 control) with randomisation (stratified by practice size) and blinding of trial statistician and outcome data-collectors. Participants were adult consulters with MSK pain without indicators of serious pathologies, urgent medical needs, or vulnerabilities. Potential participant records were tagged and individuals sent postal invitations using a GP point-of-consultation electronic medical record (EMR) template. The intervention was supported by the EMR template housing the Keele STarT MSK Tool (to stratify into low, medium and high-risk prognostic subgroups of persistent pain and disability) and recommended matched treatment options. Feasibility outcomes included exploration of recruitment and follow-up rates, selection bias, and GP intervention fidelity. To capture recommended outcomes including pain and function, participants completed an initial questionnaire, brief monthly questionnaire (postal or SMS), and 6-month follow-up questionnaire. An anonymised EMR audit described GP decision-making. Results GPs screened 3063 patients (intervention = 1591, control = 1472), completed the EMR template with 1237 eligible patients (intervention = 513, control = 724) and 524 participants (42%) consented to data collection (intervention = 231, control = 293). Recruitment took 28 weeks (target 12 weeks) with > 90% follow-up retention (target > 75%). We detected no selection bias of concern and no harms identified. GP stratification tool fidelity failed to achieve a-priori success criteria, whilst fidelity to the matched treatments achieved complete success. Conclusions A future definitive cluster RCT of stratified care for MSK pain is feasible and is underway, following key amendments including a clinician-completed version of the stratification tool and refinements to recommended matched treatments.