Molsberger 2002.

Methods	Design: three group parallel trial Purpose: examine the effect of acupuncture on chronic low back pain
Participants	Patients: patients with low back pain of more than 6 weeks duration Baseline comparability: yes (age, pain)
Interventions	Placebo: superficial needling at sites not regarded acupuncture sites (12 sessions over 4 weeks) Untreated: no needling Experimental: needling at acupuncture sites (Co‐intervention: conservative orthopaedic treatment (physiotherapy, exercise, back school, mud packs, infrared heat therapy, and diclofenac on demand))
Outcomes	Proportion of patients with 50% reduction of 100 mm pain VAS at one month Proportion of patients with 50% reduction of 100 mm pain VAS at follow‐up Proportion of patients with excellent or good ratings on a four‐point box scale
Notes	According to protocol we extracted the post treatment outcome data at one month, overruling a secondary principle of extracting the primary outcome of a trial (follow up data at three months). The effect of placebo was neutral at post treatment (RR = 1.16, 0.86 to 1.56), but positive at follow‐up (RR = 0.64, 0.43 to 0.95). The drop out rate in the two groups was (3+7)/121 = 8% at one month, and (19+23)/121 = 35% at three months.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Low risk	'computer generated randomisation list'
Allocation concealment?	Low risk	'central telephone randomisation'
Blinding? Treatment provider	Unclear risk	NS
Blinding? Outcome assessor	Unclear risk	Not relevant as patient reported outcome
Incomplete outcome data addressed? All outcomes	Low risk	Drop‐out < 15%
Free of selective reporting?	Unclear risk	No protocol available
Free of other bias?	High risk	See notes
No signs of variance inequality or skewness?	Unclear risk	Not relevant (binary outcome)
Trial size > 49?	Low risk	N = 111
Clearly concealed allocation + trial size > 49 + drop‐out max 15%	Low risk	All three categories fulfilled