title: Assessing the comparative effectiveness of Tai Chi versus physical therapy for knee osteoarthritis: design and rationale for a randomized trial.
abstract: BACKGROUND
  Knee osteoarthritis (OA) causes pain and long-term disability with annual healthcare costs exceeding $185 billion in the United States. Few medical remedies effectively influence the course of the disease. Finding effective treatments to maintain function and quality of life in patients with knee OA is one of the national priorities identified by the Institute of Medicine. We are currently conducting the first comparative effectiveness and cost-effectiveness randomized trial of Tai Chi versus a physical-therapy regimen in a sample of patients with symptomatic and radiographically confirmed knee OA. This article describes the design and conduct of this trial.
  
  
  METHODS
  A single-center, 52-week, comparative effectiveness randomized controlled trial of Tai Chi versus a standardized physical-therapy regimen is being conducted at an urban tertiary medical center in Boston, Massachusetts. The study population consists of adults ≥ 40 years of age with symptomatic and radiographic knee OA (American College of Rheumatology criteria). Participants are randomly allocated to either 12 weeks of Tai Chi (2x/week) or Physical Therapy (2x/week for 6 weeks, followed by 6 weeks of rigorously monitored home exercise). The primary outcome measure is pain (Western Ontario and McMaster Universities WOMAC) subscale at 12 weeks. Secondary outcomes include WOMAC stkiffness and function domain scores, lower extremity strength and power, functional balance, physical performance tests, psychological and psychosocial functioning, durability effects, health related quality of life, and healthcare utilization at 12, 24 and 52 weeks.
  
  
  CONCLUSIONS
  This study will be the first randomized comparative-effectiveness and cost-effectiveness trial of Tai Chi versus Physical Therapy in a large symptomatic knee OA population with long-term follow up. We present here a robust and well-designed randomized comparative-effectiveness trial that also explores multiple outcomes to elucidate the potential mechanisms of mind-body effect for a major disabling disease with substantial health burdens and economic costs. Results of this study are expected to have important public health implications for the large and growing population with knee OA.
  
  
  BACKGROUND
  ClinicalTrials.gov identifier: NCT01258985.
authors.affiliation: Center for Integrative Medicine and Division of Rheumatology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA. CWang2@tuftsmedicalcenter.org.
authors.forename: Chenchen
authors.initials: C
authors.lastname: Wang
authors.forename: Maura D
authors.initials: MD
authors.lastname: Iversen
authors.forename: Timothy
authors.initials: T
authors.lastname: McAlindon
authors.forename: William F
authors.initials: WF
authors.lastname: Harvey
authors.forename: John B
authors.initials: JB
authors.lastname: Wong
authors.forename: Roger A
authors.initials: RA
authors.lastname: Fielding
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Driban
authors.forename: Lori Lyn
authors.initials: LL
authors.lastname: Price
authors.forename: Ramel
authors.initials: R
authors.lastname: Rones
authors.forename: Tressa
authors.initials: T
authors.lastname: Gamache
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Schmid
mesh_terms: D000328:Adult; D000368:Aged; D002985:Clinical Protocols; D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D007717:Knee / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000191:economics / Q000503:physiopathology / Q000628:therapy*; D010147:Pain Measurement; D026741:Physical Therapy Modalities / Q000191:economics; D011788:Quality of Life; D026302:Tai Ji / Q000191:economics; D016896:Treatment Outcome