Ercelen 2003.

Methods	RTC
Participants	VKV American Hospital, Pain Management Department, Istanbul, Turkey (N = 39) Inclusion criteria Chronic low‐back pain Receiving some kind of conservative treatment ≥ 2 years Persistent pain Quality of life severely affected No nerve compression found Concordant pain reproduced at 1 or 2 suspicious levels with no pain or discordant pain with adjacent disc stimulation Exclusion criteria Spinal stenosis, instability, spondylolisthesis, diabetes mellitus, tumour infiltration, coagulation disorders, clinical radiculopathy, other neurological abnormalities or systemic inflammatory diseases
Interventions	Group A was treated with a 120‐second 80°C lesion of the intervertebral disc after injection of a mixture of 1 to 2 mL of dye and local anaesthetic (N = 20) Group B was treated with a 360‐second 80°C lesion of the intervertebral disc after injection of a mixture of 1 to 2 mL of dye and local anaesthetic (N = 19)
Outcomes	No significant changes between groups in pain and function Pain intensity: change in VAS score at 1 month: ‐3.4 (A), ‐2.9 (B) Pain intensity: change in VAS score at 6 months: ‐1.3 (A), ‐1.4 (B) Function: change in ODI score at 1 month: ‐16.1 (A), ‐17.8 (B) Function: change in ODI score at 6 months: ‐3.6 (A), ‐4.3 (B)
Notes	Dropouts: 2 (5%)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Participants randomly assigned to 2 treatment groups by computer
Allocation concealment (selection bias)	Unclear risk	Remained unclear from text
Blinding (performance bias and detection bias) All outcomes ‐ patients?	High risk	Participants not blinded
Blinding (performance bias and detection bias) All outcomes ‐ providers?	High risk	Providers not blinded
Blinding (performance bias and detection bias) All outcomes ‐ outcome assessors?	High risk	Participants not blinded and all outcomes participant reported
Incomplete outcome data (attrition bias) All outcomes ‐ drop‐outs?	Low risk	Two participants (5%) dropped out
Incomplete outcome data (attrition bias) All outcomes ‐ ITT analysis?	Low risk	Attrition bias unlikely because of design ?
Selective reporting (reporting bias)	Unclear risk	No protocol available
Baseline characteristics similar?	Low risk	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‐session intervention
Timing of outcome assessments similar?	Low risk	Outcomes measured directly after procedure and at 1 week, 2 weeks, 1 month, 2 months, 3 months and 6 months after procedure