Azevedo 2017.

Study characteristics
Methods	Study design: RCT (NCT02221609) Setting: Brazil, mixed Exercise groups: 2 Comparison groups: 0
Participants	Number of participants: 148 (E1 = 74, E2 = 74) Chronic LBP duration: 85.05 months (long) Neurological/radicular symptoms: Some participants Mean age (years): 42 Sex (female): 61%
Interventions	Exercise Group 1 (E1): Movement system impairment‐based classification treatment: involved patient education, analysis and modification of daily activities, and prescription of specific exercises; type = functional restoration; duration = 8 weeks; dose = low; design = individualised; delivery = individual; additional intervention = advice/education Exercise Group 2 (E2): Strengthening and stretching of the core and lower limbs; type = strengthening & stretching; duration = 8 weeks; dose = low; design = partially individualised; delivery = individual; additional intervention = advice/education
Outcomes	Core outcomes reported: Pain (Numerical Rating Scale); function (Roland‐Morris Disability Questionnaire); Global Perceived Health or Recovery (Global Perceived Health or Recovery (Global Perceived Effect scale)) Follow‐up time periods available for syntheses: 8.7 weeks (short); 26 weeks (moderate)
Notes	Conflicts of interest: None to declare Funding source: Conselho Nacional de Desenvolvimento Cientifico e Tecnologico/Brazil (CNPQ grant number 470273/2013‐5); Coordenacao de Aperfeicoamento de Pessoal de Nıvel Superior Other: None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation method entailed "generating a randomization schedule in Excel".
Allocation concealment (selection bias)	Low risk	Allocations were concealed using sealed, opaque, and sequentially numbered envelopes.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	1. Patients could not be blinded to allocation due to the nature of the treatments; 2. Unlikely that lack of patient blinding caused deviation from intended interventions because patients had no control over the delivery of intervention.
Blinding of care provider (performance bias)	Low risk	1. Care providers could not be blinded to allocation due to the nature of the treatments; 2. Protocol and progression of exercises was provided in the appendix; one arm involved movement and alignment information which could have been provided to the other group in casual physiotherapy sessions.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	1. Outcome assessors for pain and function were the patients themselves, who could not be blinded due to the nature of the treatments; 2. Pain and functional questionnaires are subjective, and responses could be altered by awareness of intervention; 3. Neither treatment is obviously better than the other; no reason to alter patient response.
Incomplete outcome data (attrition bias) All outcomes	Low risk	1. Loss to follow‐up at each time point was only 2% (3/148).
Participants analysed in group allocated (attrition bias)	Low risk	1. Intention‐to‐treat analysis was conducted.
Selective reporting (reporting bias)	Low risk	1. Study was analysed and reported according to registered protocol (NCT02221609).
Groups similar at baseline (selection bias)	Low risk	Groups were similar on all relevant characteristics at baseline.
Co‐interventions avoided or similar (performance bias)	High risk	No information on co‐interventions reported in this study
Compliance acceptable in all groups (performance bias)	High risk	Mean adherence was 67% and 49.3% in the comparator and experimental intervention, respectively.
Timing of outcome assessment similar in all groups (detection bias)	Low risk	1. Outcome assessments were identical for all patients, regardless of treatment group; 2. Numeric Rating Scale (for pain) and Roland‐Morris Disability Questionnaire (for function) are well‐validated tools in the low back pain context.
Other bias	Low risk	No other sources of bias noticed; generally well‐reported