Shanthanna 2014.

Methods	RCT
Participants	St Joseph's Healthcare Hamilton, Ontario, Canada (N = 31) Inclusion criteria 18 years or older History of chronic lumbar radicular pain ≥ 4 months Average pain score of 5 on VAS of 0 to 10 Failure of conservative therapy (e.g. physiotherapy, medication trial) Exclusion criteria Patient refusal to participate Any contraindication to neuraxial injections History of predominant back pain over leg pain Significant anatomical deformity (congenital or acquired), making it difficult to access the foramen as evidenced by computed tomography/magnetic resonance imaging Severe psychiatric illness Presence of cancer accounting for back pain Inability to communicate in English Allergy to local anaesthetics or contrast medium History of motor findings in affected leg
Interventions	Experiment group Study group participants had PRF treatment at 42°C for 120 seconds to dorsal root ganglion (N = 16) Control  group Participants in control group had low‐intensity (0.2 V) sensory stimulation (50 Hz) with no active treatment for the same duration (N = 15)
Outcomes	PRF group achieved 32% (5 out of 16 participants) more than 50% decrease in VAS score (0 to 10) compared with 25% more (3 out of 15 participants) in placebo group
Notes	Dropouts: 2 (6%)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Allocation was given to the assistant in a sealed opaque envelope to be handed over to the nurse operating the RF machine
Allocation concealment (selection bias)	Low risk	Enrolled participants were randomly assigned on the day of the study intervention at a central location by a single research person, who was not involved in any other part of the study
Blinding (performance bias and detection bias) All outcomes ‐ patients?	Low risk	Participants in control group had low‐intensity sensory stimulation, with no active treatment for the same duration. This was done to ensure participant blinding
Blinding (performance bias and detection bias) All outcomes ‐ providers?	Low risk	Allocation was given to the assistant in a sealed opaque envelope to be handed over to the nurse operating the RF machine All other operating room personnel, including the physician performing the intervention and the participant, were blinded to randomisation and treatment
Blinding (performance bias and detection bias) All outcomes ‐ outcome assessors?	Low risk	Assessor (blinded to randomisation code) met with all participants in recovery
Incomplete outcome data (attrition bias) All outcomes ‐ drop‐outs?	Low risk	Dropouts: 2 of 31 participants
Incomplete outcome data (attrition bias) All outcomes ‐ ITT analysis?	Low risk	As the study was analysed using the intention‐to‐treat principle, missing outcomes were imputed using 'multiple imputation'
Selective reporting (reporting bias)	Low risk	Protocol showed same outcomes
Baseline characteristics similar?	Low risk	Table 1. Groups comparable on relevant demographic and clinical variables
Co‐interventions avoided or similar?	Unclear risk	Remained unclear from text
Compliance acceptable?	Low risk	Irrelevant: single intervention
Timing of outcome assessments similar?	Low risk	1 month and 3 months of follow‐up