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

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

	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

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.
²WOMAC Pain is the primary outcome at 12 weeks; the other collection times are secondary outcome variables.
³PROMIS questionnaires include PROMIS Pain Impact, PROMIS Physical Function, PROMIS Depression, PROMIS Anxiety, PROMIS Sleep Disturbance, Satisfaction with Social Roles, and PROMIS HAQ.
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.
⁵The Credibility-Expectance Questionnaire are given out before the start of the first intervention session.
⁶Functional Performance Tests include timed chair stand, berg balance, six minute walk, 20-meter walk, gait analysis, muscle strength and power, and postural sway.

ISSN: 2662-7671