Objective:
Antibiotic therapy for chronic low back pain (CLBP) associated with Modic changes remains debated, with uncertainty about its clinical value and the feasibility of evaluating it in a definitive randomised controlled trial (RCT). The AUSMODIC trial is designed to evaluate the efficacy of a 100-day course of antibiotics in people with CLBP and Modic changes. Before a definitive trial, it is important to determine whether the intervention and proposed trial procedures are acceptable and feasible for patients and clinicians. This study aims to optimise recruitment, participant engagement, and trial implementation to inform a definitive RCT.
Methods:
This protocol includes two stages. First, a qualitative study will explore the prospective acceptability of the AUSMODIC trial from patient and clinician perspectives, guided by the Theoretical Framework of Acceptability. Semi-structured interviews will be conducted with patients with CLBP and Modic changes, and clinicians involved in their care. Participants will be recruited through imaging providers, professional networks, and consumer groups. Interviews will be conducted online or in person, audio-recorded, transcribed, and analysed using thematic analysis with inductive and deductive coding.
Second, a pilot RCT will assess the feasibility of key AUSMODIC trial procedures. Recruitment feasibility will be evaluated using screening-to-enrolment ratios and recruitment rates. Trial delivery feasibility will be assessed through completion of electronic consent, telehealth assessments, randomisation, and follow-up procedures. Intervention feasibility will be evaluated through adherence to antibiotic and probiotic regimens, biological sample collection, and outcome data completion.
Results:
The study will identify barriers and enablers to recruitment, participation, clinician engagement, intervention delivery, biological sample collection, and outcome data collection. Findings will refine trial procedures, optimise participant experience.
Conclusion:
This study will determine whether the key components of AUSMODIC can be delivered acceptably and feasibly in the Australian context, and will inform progression to a definitive RCT.