Table 1 Trial objectives, outcomes and analyses

Feasibility objectives

Feasibility outcomes

Evaluation metrics

Analysis

Intervention adherence

Percentage of patients receiving at least 3 of the 4 trial intervention components

 > 90% feasible; 80–90% to consider design modifications; < 80% not feasible

Descriptive

Patient recruitment

Time to recruit target sample size

We aim to recruit 100 patients in 4 months

Patient retention

Percentage of follow up at 12 months

 > 90% feasible; 80–90%-consider design modifications;

 < 80%-not feasible

Clinical Objectives

Clinical outcomes

Analysis

Opioid-free pain control

Time to three or more consecutive days of < 4/10 pain score on a 0–10 NRS with no opioid use for the operated knee

hazard ratios, 95% CI; Kaplan–Meier survival curve

Presence of chronic postsurgical pain (CPSP) at 3, 6, 9 and 12 months

Presence of CPSP as adopted in the International Classification of Diseases (ICD)-11 version by World Health Organization

descriptively as point estimates and 95% CI by group, with minimally important differences presented for context

CPSP pain intensity at rest and movement

Average pain score over the previous week in 0–10 NRS

Presence of persistent opioid use (POU)

Presence of daily opioid use, started after surgery or increased after surgery (binary)

Satisfaction with pain control at 3, 6, 9 and 12 months

Using a 0 to 100 scale (0 = extremely dissatisfied, 100 = extremely satisfied)

Return to function at 3, 6, 9, and 12 months

Using the Return to Function questionnaire

Knee function at 3, 6, 9 and 12 months

Using Oxford Knee Scale (OKS)

Quality of Life

Using Euro-Qol 5 Dimensions (EQ-5D) instrument

Economic analysis

Intervention costs and healthcare resource utilization information as well as information on productivity (e.g. time missed from work) will be collected using a self-administered questionnaire, developed for the purpose of this study

QALYs associated with each study arm will be reported as point estimates along with confidence intervals but not compared in a formal economic evaluation

Complications

Surgery-related and knee-related adverse events, pain medication related adverse events, readmissions, and serious adverse events (SAEs)

descriptively by group