Table 3.

Methodological implications derived from the listed domains, main themes and supporting codes used to inform the Progressive Resistance Training Versus Total Hip Arthroplasty (PROHIP) trial protocol

Domain	Main theme(s)	Supporting code(s)	Methodological implications for the PROHIP trial protocol
Patient ‘buy in’	Treatment expectations and beliefs impact management choices Factors influencing clinical trial integrity and feasibility	Treatment without surgery is unlikely to lead to recovery Clinician authority impacts the management narrative The ‘surgery versus exercise’ debate Who is considered eligible for surgery? Facilitators and barriers for surgery and exercise in a clinical trial context	Guided implementation of a parallel observational study investigating the generalisability of the clinical trial, since many patients probably may decline participation in the trial. Guided development of retention procedures (ie, instructions of study personnel to encourage patient completion), statistical analysis plan (ie, handling of missing data, sensitivity and exploratory analyses, and subgroup and causal mediation analysis), and exercise protocol (ie, effective supervision and habitualised exercise protocol).
Enrolment strategies	Treatment expectations and beliefs impact management choices Factors influencing clinical trial integrity and feasibility	Clinician authority impacts the management narrative The ‘surgery versus exercise’ debate Who is considered eligible for surgery?	Guided development of instruction and training strategy in the enrolment procedures. Guided implementation of generic guidance and neutral narrative during enrolment procedures to provide verbal information about the trial. Guided clinician roles in enrolment procedures (ie, eligibility assessment, provider of trial information to the patients) and selection of an independent clinician group to provide detailed verbal information about the trial to facilitate communication of clinical equipoise.
Patient information materials	Treatment expectations and beliefs impact management choices Factors influencing clinical trial integrity and feasibility	Treatment without surgery is unlikely to lead to recovery Clinician authority impacts the management narrative The ‘surgery versus exercise’ debate Facilitators and barriers for surgery and exercise in a clinical trial context	Guided and informed content for the written patient materials and this included information on current evidence of treatment effects for surgery and exercise, trial objective and procedures, randomisation process, content of baseline and follow-up sessions, risks and harms, treatment crossover and withdrawal procedures, clinical implications and funding. Guided development of the neutral narrative used in the written patient materials to facilitate communication of clinical equipoise.
Important clinical outcomes	Treatment expectations and beliefs impact management choices Factors influencing clinical trial integrity and feasibility	Treatment without surgery is unlikely to lead to recovery Improvements in hip pain and hip function are the most important outcomes	Guided selection of hip pain and function as primary outcome. Guided selection of hip-related quality of life and functional performance (ie, gait function) as key secondary outcomes Guided selection of patient acceptable symptom state and muscle strength as exploratory outcomes.