Using discrete choice experiments as a decision aid in total knee arthroplasty: study protocol for a randomised controlled trial

Table 3 SPIRIT trial study schedule

Activity/assessment	Enrolment	Randomisation	t ₁	t ₂	t ₃	t ₄
Activity/assessment	−t₁	0	t ₁	t ₂	t ₃	t ₄
Baseline data, demographics	X
Eligibility screen	X
Informed consent	X
Randomisation		X
Baseline assessments battery^a			X
Expectation survey^b				X
Total knee arthroplasty					X
12-month assessments^c						X

^aBaseline assessments will be given to patients during their preadmission appointments and completed with the assistance of the study coordinator. Assessment items include: Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index; Veterans RAND Health Survey mental component score (VR-12); Big Five Personality Inventory; Locus of Control; Risk Attitudes; Hospital for Special Surgery: Knee Surgery Expectations Survey; Fear Avoidance Beliefs Questionnaire; Pain Catastrophising Scale; Life Orientation Test-revised Questionnaire; and the DCE survey for patients in the intervention group
^bPatients will complete the Hospital for Special Surgery: Knee Surgery Expectations Survey 1 week prior to scheduled TKA via phone with study coordinator
^c12-month assessment will be given to patients at their 1-year post-TKA surgical review visit. Assessments include: WOMAC; VR-12 (this assessment is routine for all patients undergoing TKA)

ISSN: 1745-6215