Nath 2008.

Methods	RCT
Participants	Smartkliniken, Umea, Sweden. Department of Hand Surgery, Orebro University Hospital, Orebro, Sweden (N = 40) Inclusion criteria Adult participants Continuous low back pain ≥ 2 years No response to previous treatment ≥ 80% relief of pain following controlled medial branch blocks Exclusion criteria Pregnancy Coagulopathy Malignancy Infection Mental handicap Psychiatric disorder Motor deficit or any other indication for surgical treatment Live too far away to be able to participate
Interventions	Experiment group RF denervation of lumbar facet joint for 60S at 85°C (N = 20) Control group Identical to experiment group, except no current was used and electrode tip remained at body temperature (N = 20)
Outcomes	Significant changes in generalised pain 6 months after treatment. No significant changes in back pain Back pain: change in VAS score at 6 months: ‐2.1 (E), 0.7 (C) Generalised pain: change in VAS score at 6 months: 1.93 (E), 0.37 (C)
Notes	Dropouts: none
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomisation schedules used
Allocation concealment (selection bias)	Unclear risk	Remained unclear from text
Blinding (performance bias and detection bias) All outcomes ‐ patients?	Low risk	Participants blinded to their assignment throughout study period
Blinding (performance bias and detection bias) All outcomes ‐ providers?	Low risk	RF machine placed behind operator, who was unaware of current level of another operator
Blinding (performance bias and detection bias) All outcomes ‐ outcome assessors?	Low risk	All outcome measurements performed by same orthopedic surgeon at another institution
Incomplete outcome data (attrition bias) All outcomes ‐ drop‐outs?	Low risk	No dropouts
Incomplete outcome data (attrition bias) All outcomes ‐ ITT analysis?	Low risk	Participants analysed by group; no dropouts
Selective reporting (reporting bias)	Unclear risk	No protocol available
Baseline characteristics similar?	High risk	Participants in RF treatment group had significantly more generalised pain, low back pain and referred pain to the leg when compared with placebo group. All hip movements were worse in the RF treatment group
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 participants re‐examined after 6 months