Keane 2017.

Study characteristics
Methods	Study design: RCT Setting: England, general population Exercise groups: 2 Comparison groups: 1
Participants	Number of participants: 29 (E1 = 10, E2 = 10, C1 = 9) Chronic LBP duration: Not specified (not specified) Neurological/radicular symptoms: No participants Mean age (years): 47 Sex (female): 83%
Interventions	Exercise Group 1 (E1): Aquastretch: assisted stretching of the whole body in water; type = stretching; duration = 12 weeks; dose = low; design = partially individualised; delivery = individual; additional intervention = none Exercise Group 2 (E2): Land based stretching; type = stretching; duration = 12 weeks; dose = low; design = standardised; delivery = group; additional intervention = none Comparison Group 1 (C1): Usual care/no treatment (control group: no intervention)
Outcomes	Core outcomes reported: Pain (Visual Analogue Scale); function (Modified Oswestry Disability Index Oswestry Low Back Pain (MOLBPQ)) Follow‐up time periods available for syntheses: 12 weeks (short)
Notes	Conflicts of interest: Not reported Funding source: No funding received Other: Information modified for author contact
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Subjects were assigned randomly; sequence generation not described.
Allocation concealment (selection bias)	Low risk	Sealed envelopes were used.
Blinding of participants and personnel (performance bias) All outcomes	High risk	1. Not mentioned, but due to nature of intervention patients were likely not blinded; 2. Control group maintained pre‐trial regimen; may not be consistent controls; two exercise groups were different enough that expectations may have differed; 3. Control group maintained pre‐trial regimen (i.e. exercise) but did not receive anything from this study; this may bias them as control; 4. Treatments in the control group may have altered outcomes.
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. Unlikely that control group had no contact with care providers and other interventions were explicit (land versus pool)
Blinding of outcome assessment (detection bias) All outcomes	High risk	1. Outcomes in question were pain and function which were assessed by the patients who were not blinded; 2. Pain and functional questionnaires are subjective, and responses could be altered by awareness of intervention; 3. One group was control, while the other two received different interventions.
Incomplete outcome data (attrition bias) All outcomes	Low risk	1. 69% of people recruited took part, but one dropped out after the study started.
Participants analysed in group allocated (attrition bias)	Low risk	1. Not explicitly mentioned, however, it seemed like intention‐to‐treat was done; no dropouts and no deviations mentioned
Selective reporting (reporting bias)	Low risk	1. No obvious omissions despite lack of linked protocol
Groups similar at baseline (selection bias)	Low risk	No significant differences in baseline age; there were other important variables such as body mass index and pain duration that were not reported on.
Co‐interventions avoided or similar (performance bias)	Low risk	Co‐interventions were avoided for exercise groups; no new interventions were recommended for the controls.
Compliance acceptable in all groups (performance bias)	High risk	No information on compliance with assigned intervention; unlikely to be perfect compliance
Timing of outcome assessment similar in all groups (detection bias)	Low risk	1. All subjects submitted visual analogue scale measures by email once a week; all Modified Oswestry Low Back Pain Questionnaire questionnaires were completed at the first meeting and again at weeks 6 and 12 2. Visual Analogue Scale and Modified Low Back Pain Disability Questionnaire are valid measures.
Other bias	Low risk	No other obvious sources of bias