Kroll 2008.

Methods	RCT
Participants	Henry Ford Hospital IRB, Detroit, Michigan, USA (N = 26) Inclusion criteria 18 years of age and older ASA physical status I, II and III Unilateral or bilateral lumbar back pain for longer than 1 month No radiating symptoms below the knee > 50% pain reduction based on mean VAS after 2 separate diagnostic medial branch blocks with 1.0 mL of 0.5% bupivacaine Exclusion criteria History of previous back surgery Presence of neurological deficits Claudication Active psychiatric disorder Bleeding disorder Involved in current litigation Ongoing workers’ compensation claims Disc herniation and spinal stenosis (ruled out radiographically)
Interventions	Continuous RF group Continuous RF thermocoagulation lesioning performed at 80°C for 75S (N = 13) Pulsed RF group Pulsed RF lesioning at 42°C with pulse duration of 20 ms and pulse rate of 2 Hz for 120S (N = 13)
Outcomes	No significant differences between groups at 3 months after treatment for pain (zero to 100) and function Pain intensity: change in VAS score at 3 months: ‐24.3 (CRF) and ‐11.3 (PRF) Function: change in ODI score at 3 months: ‐10.3 (CRF), ‐2.7 (PRF)
Notes	Dropouts: 24 (48%)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation via random numbers generator
Allocation concealment (selection bias)	Unclear risk	Remained unclear from text
Blinding (performance bias and detection bias) All outcomes ‐ patients?	Unclear risk	Unclear whether difference between CRF and PRF could be noticed by participants
Blinding (performance bias and detection bias) All outcomes ‐ providers?	Unclear risk	Remained unclear from text
Blinding (performance bias and detection bias) All outcomes ‐ outcome assessors?	Unclear risk	Remained unclear from text
Incomplete outcome data (attrition bias) All outcomes ‐ drop‐outs?	High risk	Dropouts: 24 (48%)
Incomplete outcome data (attrition bias) All outcomes ‐ ITT analysis?	High risk	No ITT analysis. Only 26 of 50 participants completed follow‐up evaluation; their data were analysed
Selective reporting (reporting bias)	Unclear risk	No protocol available
Baseline characteristics similar?	Unclear risk	Baseline characteristics recorded for only 26 of 50 participants who completed follow‐up evaluation
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	Three months after treatment, VAS and Oswestry scores were measured