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Table 1 Sequence of trial measurements for primary and secondary outcomes 1

From: Assessing the comparative effectiveness of Tai Chi versus physical therapy for knee osteoarthritis: design and rationale for a randomized trial

  Baseline Intervention Week 12 Week 24 Week 52
Time (Months) -1 1-3 3 6 12
Primary outcome variable      
WOMAC – Pain2 x x x x x
Secondary outcome variables      
WOMAC – Physical Function x x x x x
WOMAC – Stiffness x x x x x
Patients’ Global OA Severity x   x x x
SF-36 x   x x x
Beck II Depression Inventory x   x x x
Perceived Stress Scale x   x x x
Chronic Pain Self-Efficacy x   x x x
Social Support x   x x x
OES for Exercise x   x x x
OES for Tai Chi/PT   x    
PROMIS3 x   x x x
Health Assessment Questionnaire x   x x x
NEO Five-Factor Inventory4 x   x x x
Five Facet Mindfulness x   x x x
Credibility-Expectancy5   x x   
Pre-Clinical Disability x   x x x
Self-Reported Alignment x     
CHAMPS x   x x x
Functional Performance Tests6 x   x x x
Body Mass Index x   x x x
Medications x   x x x
Adverse Events x x    
Adherence x x x x x
  1. 1WOMAC = Western Ontario and McMaster Universities Osteoarthritis Index, SF-36 = Medical Outcome Survey Short-Form 36, PROMIS = Participant-Reported Outcomes Measurement Information System, OES = Outcome Expectations Scale, PT = Physical Therapy.
  2. 2WOMAC Pain is the primary outcome at 12 weeks; the other collection times are secondary outcome variables.
  3. 3PROMIS questionnaires include PROMIS Pain Impact, PROMIS Physical Function, PROMIS Depression, PROMIS Anxiety, PROMIS Sleep Disturbance, Satisfaction with Social Roles, and PROMIS HAQ.
  4. 4The NEO Five-Factor Inventory and Self-Reported Alignment are given out once over the course of the study at the earliest available evaluation period.
  5. 5The Credibility-Expectance Questionnaire are given out before the start of the first intervention session.
  6. 6Functional Performance Tests include timed chair stand, berg balance, six minute walk, 20-meter walk, gait analysis, muscle strength and power, and postural sway.