Gibbs 2018.

Methods	Study design: randomised controlled trial Study duration: 6 months Dropout: 3% at 1 month Location: USA Recruitment: via fliers, University‐based electronic mailings and University of Pittsburgh research registries
Participants	Population: office employees from the greater Pittsburgh area working at least 20 hours per week at a desk Intervention group: 13 participants, all with baseline pain Control group: 14 participants, all with baseline pain Included criteria: chronic LBP defined as persistent pain for at least 3 months resulting in pain on more than half the days over the last 6 months; LBP disability as defined by an Oswestry Diability Index > 10%; current desk work ≥ 20 hours/week; stable employment; approval from supervisor to participate and install a desk attachment, Internet access to complete questionnaires Excluded criteria: not providing informed consent; cardiovascular event in the last 6 months; comorbidity that limited ability to reduce sedentary behaviour; recent or planned back surgery; symptoms consistent with more serious spinal condition; currently using a height‐adjustable/standing workstation; currently planning to get pregnant; blood pressure ≥ 160/100 mmHg Baseline characteristics: intervention group participated in more occupational MVPA than control group, but overall MVPA was consistent between groups. Education level was higher in the control group, so group comparisons were adjusted for education
Interventions	Intervention Description of intervention: behavioural counselling, use of sit‐stand attachment, activity prompter to reduce prolonged sedentary behaviour Duration of intervention: 6 months Intensity of intervention: monthly counselling session with physical therapist or trained interventionist Control Description of intervention: no intervention but offered 60‐minute learning session at end of 6‐month intervention Duration of intervention: 6 months Intensity of intervention: not stated
Outcomes	Outcome name, measurement tool, body region Musculoskeletal pain Visual analog scale (VAS) from 0 (better) to 10 (worse) Usual, worst, and best LBP in the past week Usual neck, upper back, and leg pain Disabilty Oswestry Disability Index ‐ % disability from ODI
Identification
Notes	Sponsorship source: nil relevant
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation	Low risk	Judgement comment: randomisation was done using sealed envelopes in blocks of 4 participants
Allocation concealment	Low risk	Judgement comment: randomisation was done using sealed envelopes in blocks of 4 participants
Blinding of participants and personnel	High risk	Quote: "most participants worked in separate locations, with the exception of some university employees working on the same floor of a building (one cluster of 2; one cluster of 3); the investigators asked these participants not to discuss the study among each other to limit contamination" Judgement comment: attempts were made to avoid contamination between intervention and control participants, but blinding was not possible
Blinding of outcome assessment	High risk	Judgement comment: physical function measured by blinded researcher but for the other outcome assessment, blinding of outcome personnel not reported. In addition, as self‐reported musculoskeletal symptoms was the primary outcome measure and participants were not blinded to the intervention, risk of bias is high
Incomplete outcome data	Low risk	Judgement comment: 1 intervention participant withdrew after 1 month for personal reasons. One control participant withdrew at 2 months for personal reasons, and 1 control participant withdrew due to extended work leave for a medical procedure unrelated to LBP. Completion rate of monthly assessment questionnaires was 93%. Sensitivity analysis between completers only; reported data were similar
Selective reporting	Low risk	Judgement comment: all pain and disability data were reported according to the protocol in the trial registry
Baseline imbalance	Low risk	Judgement comment: there was baseline imbalance for education between intervention groups. Analyses were subsequently adjusted for education