TAICHIKNEE trial: protocol for an embedded pragmatic, individually randomised group-treatment trial of remotely delivered Tai Chi for knee osteoarthritis across US healthcare systems

Introduction: Symptomatic knee osteoarthritis (OA) is a leading cause of chronic pain and disability and is associated with substantial healthcare utilisation and costs. In-person Tai Chi, a multidimensional mind-body exercise, is recommended as a non-pharmacological therapy for knee OA; however, delivery through in-person classes may limit scalability across US healthcare systems. Remote delivery may reduce logistical barriers and facilitate integration into routine care, but evidence regarding its effectiveness and implementation in real-world healthcare settings remains limited. We describe the protocol for TAICHIKNEE, an embedded pragmatic trial evaluating remotely delivered group Tai Chi plus routine care vs routine care alone for adults with symptomatic knee OA.

Methods and analysis: TAICHIKNEE is a 12-month, fully decentralised, embedded pragmatic, individually randomised group-treatment trial with an effectiveness-implementation hybrid type 1 design conducted across five US healthcare systems. The trial will randomise 480 adults aged ≥50 years with symptomatic, clinician-diagnosed knee OA in a 1:1 ratio within six sequential cohorts, stratified by healthcare system and sex. Participants assigned to Tai Chi will receive 24 live, instructor-led 60-minute videoconference sessions over 12 weeks in addition to routine care; control participants will continue routine care. The cohort randomisation date defines time zero for both groups. The primary outcome is Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain at 3 months, analysed using a partially nested mixed-effects model that accounts for clustering within Tai Chi classes and adjusts for baseline WOMAC pain and prespecified covariates. Key secondary outcomes are Patient-Reported Outcomes Measurement Information System Pain Interference and SF-12 health-related quality of life scores at 3 months, and knee joint injections over 12 months. Safety will be assessed throughout the 12-month follow-up. The implementation evaluation will concurrently assess intervention fidelity, stakeholder perspectives and participant and instructor experiences using Consolidated Framework for Implementation Research-informed stakeholder interviews, fidelity assessments and surveys to identify factors influencing implementation and inform future sustainment and spread across healthcare systems.