Costantino 2014.

Methods	RCT
Participants	54 participants. 1. Back School group n = 27. 2. Hydrotherapy group n = 27. Inclusion criteria: participants aged between 65 and 80 years; diagnosis of chronic non‐specific low back pain. Exclusion criteria: presence of musculoskeletal disorders, severe heart failure, or internal medicine pathologies that could interfere with moderate physical activity; fever or infectious disease; systemic inflammatory or rheumatologic diseases; previous spinal surgery or a history of vertebral traumas/fractures; instrumental physical therapies or physiotherapeutic therapies in the previous 3 months.
Interventions	1. Back School group: In the first session, individuals were informed about the anatomy of the spinal column, its functioning and ergonomic position and the basis of the pain‐inducing mechanism, psychological aspects and stress management, whereas in the following sessions they performed stretching and muscular strengthening, associated with proper breathing. 2. Hydrotherapy group: Participants at first performed walking exercises to adapt to the pool conditions, and afterwards performed bilateral stretching and selective muscle strengthening exercises.
Outcomes	1. Disability: Roland‐Morris Disability Questionnaire.
Notes	Setting not specified. Funding: N/A.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The participants were randomly allocated using computer randomisation software (RANDI2 software version 0.6.1) to the Back School programme (group A) or to the hydrotherapy programme (group B).
Allocation concealment (selection bias)	Unclear risk	The sequence generation procedure or the method of allocation were not mentioned. The title and abstract indicate that it is an RCT.
Blinding of participants and personnel (performance bias) All outcomes	High risk	No mention of any attempts to blind the participants
Blinding (performance bias and detection bias) All outcomes	High risk	No mention of any attempts to blind the care providers
Blinding of outcome assessment (detection bias) All outcomes	High risk	No mention of any attempts to blind the assessors
Incomplete outcome data (attrition bias) All outcomes	Low risk	The percentage of withdrawals and dropouts was within the acceptable rate (less than 20%).
Intention‐to‐treat Analysis	Low risk	All analyses were performed based on the intention‐to‐treat principle.
Selective reporting (reporting bias)	Low risk	It was clear that the published report included all expected outcomes.
Similarity of baseline characteristics?	Low risk	No significant difference across the groups was found.
Co‐interventions avoided or similar?	Low risk	Balanced for both groups
Compliance acceptable?	Low risk	Compliance was acceptable based on the reported intensity/dosage, duration, number, and frequency for both the intervention and control groups.
Timing outcome assessments similar?	Low risk	All important outcomes assessments for both groups were measured at the same time.