Patel 2012.

Methods	RCT
Participants	Advanced Pain Management, Green Bay, Wisconsin, USA (N = 51) Inclusion criteria Predominantly axial pain below L5 vertebrae Axial pain lasting longer than 6 months Three‐day average NRS between 4 and 8 Older than 18 years of age Failure to achieve adequate improvement with comprehensive non‐operative treatments, including but not limited to activity alteration, non‐steroidal anti‐inflammatory drugs, physical and/or manual therapy and fluoroscopically guided injections of steroids into SIJ or sacroiliac ligaments Other possible sources of low back pain reasonably excluded (by means of physical exam, medical history and magnetic resonance imaging/computed tomography/X‐ray as required), including but not limited to bone fracture, hip joint, symptomatic spondylolisthesis, tumour and other regional soft tissue structures Exclusion criteria Beck Depression Inventory score > 20 Irreversible psychological barriers to recovery Spinal pathology that may impede recovery, such as spondylolisthesis at L5/S1, or scoliosis; symptomatic moderate or severe foraminal or central canal stenosis Systemic infection or localised infection at anticipated introducer entry site Concomitant cervical or thoracic pain > 2/10 on an NRS scale Uncontrolled or acute illness Chronic severe conditions such as rheumatoid/inflammatory arthritis Pregnancy Active radicular pain Immunosuppression (e.g. AIDS, cancer, diabetes, surgery < 3 months before); workers’ compensation, injury litigation or disability remuneration Allergy to injectate or medications used during procedure High narcotics usage (> 30 mg morphine daily or equivalent) Active smokers (termination ≥ 6 months with no smoking during follow‐up period acceptable with caution) Participant unwillingness to consent to the study
Interventions	Experiment group L5 dorsal ramus RF energy applied for 150 seconds at set temperature of 60°C using pain management RF generator After coagulation of L5 dorsal ramus, sacral lateral branches of S1, S2 and S3 were targeted. RF energy was delivered for 150 seconds at set temperature of 60°C (N = 34) Control group Same procedure as in experimental group, except that RF energy was not delivered. Probe placements, procedure duration, equipment sounds and visual indications for participants were identical in both groups (N = 17)
Outcomes	Pain intensity: change in NRS score at 1 month: ‐2.7 (E), ‐1.7 (C). Not significant Pain intensity: change in NRS score at 3 months: ‐2.4 (E), ‐0.8 (C). Significant Function: change in ODI score at 1 month: ‐12 (E), ‐4 (C). Significant Function: change in ODI score at 3 months: ‐11 (E), 2 (C). Significant
Notes	Dropouts: 9 (17.6%)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants randomly assigned on a 2:1 basis to treatment group or sham group using presealed envelopes
Allocation concealment (selection bias)	Low risk	Presealed envelopes given by a nurse not involved in the study
Blinding (performance bias and detection bias) All outcomes ‐ patients?	Low risk	Participant remained visually isolated from equipment and was exposed to typical equipment noises regardless of treatment group
Blinding (performance bias and detection bias) All outcomes ‐ providers?	High risk	Physician blinding not possible
Blinding (performance bias and detection bias) All outcomes ‐ outcome assessors?	Low risk	Both assessors and participants blinded to randomisation at 1‐month and 3‐month follow‐up time points
Incomplete outcome data (attrition bias) All outcomes ‐ drop‐outs?	Low risk	Dropouts: 9 out of 51
Incomplete outcome data (attrition bias) All outcomes ‐ ITT analysis?	Low risk	Figure 1. All patients included in analysis
Selective reporting (reporting bias)	Unclear risk	No protocol available
Baseline characteristics similar?	Unclear risk	Remained unclear from text
Co‐interventions avoided or similar?	Unclear risk	Remained unclear from text
Compliance acceptable?	Low risk	Irrelevant: single‐session intervention
Timing of outcome assessments similar?	Low risk	All outcomes after 1, 3 and 6 months (cross‐over after 3 months)