The overall aim of this pilot RCT is to assess the feasibility of conducting a future definitive randomized control trial (RCT) for evaluating the effectiveness of an interprofessional rehabilitation program compared to the usual care in adults with chronic low back pain in Ethiopia.

Specific objectives of this study include:

• To evaluate the feasibility of trial procedures (recruitment rate, retention rate, adherence rate).
• To explore the feasibility and acceptability of the intervention from the patients' and care providers' perspectives.
• To estimate the preliminary treatment effect and standard deviation of the relevant clinical outcome measures (physical functioning, pain intensity, workability, HRQoL, psychological functioning) in patients with CLBP to inform sample size calculation for the definitive RCT.

Patients with chronic low back pain diagnosed through focused history and physical examination are accepted for enrolment. Each eligible patient will have an equal chance to be allocated to the intervention or control group.

Participants of the intervention group will receive interprofessional rehabilitation for four weeks. Participants of the intervention group will receive interprofessional rehabilitation that contain components aimed at enabling optimal physical, psychological, and social functioning, including addressing the work abilities of patients. The components will include a comprehensive assessment, intensified physical activities and exercises, pain education, psychological support, occupational therapy, ergonomic interventions, and vocational counselling.

Participants in the comparison group will receive the usual care according to the current standard care for patients with chronic low back pain at the University of Gondar specialized referral hospital in Ethiopia for over four weeks.

Chronic low back pain (CLBP) is the most common type of musculoskeletal pain, and it has a substantial negative consequence on the ability to engage in meaningful activities, participation in work, health-related quality of life, and social relationships. CLBP-related disability is increasing worldwide, and the majority of this increase is associated with the growing burden in low-and-middle-income countries, including Ethiopia.

A growing body of evidence from high-income countries indicates the effectiveness of interprofessional rehabilitation programs for patients with CLBP. The currently implemented biomedically focused fragmented care in low- and middle-income countries appears to have limited lasting effect, owing to long-term disability. Therefore, this pilot RCT aims to evaluate the feasibility of conducting a definitive RCT to assess the effectiveness of an interprofessional rehabilitation program compared to the usual care for patients with CLBP in Ethiopia. Accordingly, the investigators will evaluate some elements of full RCT, including recruitment and retention rate, adherence, acceptability of the intervention, sample size estimation, and participants' preliminary responses to the interventions. Hence, this study will substantially benefit in informing components of the main trial design, minimizing uncertainties, and increasing the likelihood of successfully conducting the definitive RCT in the future. In addition, this pilot RCT is expected to provide a source of evidence for other initiatives aimed at developing and implementing interprofessional rehabilitation programs in a similar context.

A two-arm parallel single-blinded pilot randomized control trial (RCT), with embedded qualitative interviews, will be employed to assess the feasibility of conducting a full RCT to evaluate the effectiveness of an interprofessional rehabilitation program compared to the usual care in patients with CLBP.

Sample size: The investigators will recruit a total of 40 (i.e., 20 in the intervention group and 20 in the control group) patients with CLBP.

A simple block randomization method with random block sizes of 4 to 8 will be employed to randomize participants into the intervention and control groups.

Data collection procedures: The data will be collected by a trained research assistant who will be blind to the group assignment using interviewer administered approach at three time points: at baseline before the start of the intervention, the 5th week immediately following the final visit for the intervention, and the 16th week (after 12 weeks of intervention completion) to investigate whether the effects are sustained over time after the completion of the intervention.

In addition to the primary and secondary outcome measures, the study participants' socio-demographic and behavioural characteristics, such as age, sex, educational level, marital status, and physical activities, will be collected at the baseline. A two-day training will be given to data collectors about the trial process, outcome measures, and tools used by PI.

For the embedded qualitative interviews, a research assistant will conduct a face-to-face, in-depth interview with treating health professionals and study participants during the intervention phase. A semi-structured interview guide will be used to conduct an interview. The interview will be conducted to explore the acceptability of the intervention and barriers and facilitators associated with the implementation of the intervention from both treating health professionals' and participants' perspectives. The investigators will also explore the perceptions and experiences of the study participants about the intervention they have received.

Data management and statistical analysis: Descriptive statistics like mean, standard deviation, proportions, and frequency distributions of all variables will be computed. The quantitative data analysis will be performed using SPSS version 27. The main analysis will be performed according to the intention-to-treat (ITT) principle.

The thematic text analysis approach as described by Braun and Clarke will be used to analyze the qualitative data.

Inclusion Criteria:

• Adults above the age of 18 years
• Patients with chronic low back pain ('pain and discomfort localized below the costal margin and above the inferior gluteal folds, with or without leg pain') that persists for 3 months or more will be included in this trial

Exclusion Criteria:

• Patients who have serious known spinal pathology (e.g., tumours, vertebral fractures, and inflammatory diseases), and spinal surgery within the last 12 months will be excluded.
• Participants with CLBP due to specific pathologies (e.g., infections, neoplasms, metastases, fractures, osteoporosis, rheumatoid arthritis, radiculopathies) or other inflammatory articular conditions (for example, ankylosing spondylitis), spinal stenosis, or fracture will also be excluded from the study

Efforts will be made to present the results at scientific conferences and publish them in a peer-reviewed journal.

In this study, research staff collecting outcome data from patients will be blinded to the group allocation. However, the treating health professionals and patients will not be blinded to group allocation due to the nature of the intervention.