Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Symptom severity
[33] Systematic review	People with TTH 4 RCTs in this analysis	Proportion of responders 3–4 months after randomisation 195/391 (50%) with acupuncture 128/312 (41%) with sham intervention	RR 1.24 95% CI 1.05 to 1.46 P = 0.009	Small effect size	acupuncture
[33] Systematic review	People with TTH Data from 1 RCT	Proportion of responders >6 months after randomisation 6/15 (40%) with acupuncture 4/15 (27%) with sham intervention	RR 1.50 95% CI 0.53 to 4.26 P = 0.45		Not significant
[33] Systematic review	People with TTH 4 RCTs in this analysis	Number of headache days 3–4 months after randomisation with acupuncture with sham intervention Absolute results not reported	MD –1.94 95% CI –3.15 to –0.72 P = 0.002	Effect size not calculated	acupuncture
[33] Systematic review	People with TTH 4 RCTs in this analysis	Headache intensity 3–4 months after randomisation with acupuncture with sham intervention Absolute results not reported	SMD –0.12 95% CI –0.28 to +0.04 P = 0.15		Not significant
[33] Systematic review	People with TTH 3 RCTs in this analysis	Headache score 3–4 months after randomisation with acupuncture with sham intervention Absolute results not reported	SMD –0.11 95% CI –0.40 to +0.18 P = 0.47		Not significant
[34] RCT	50 people with CTTH	Median headache severity (measured by Visual Analogue Scale [VAS]) 3 months –2 with laser acupuncture 0 with placebo (machine set to 0 output power)	P <0.001 Similar significant differences reported at 1 and 2 months' follow-up (P <0.001)	Effect size not calculated	laser acupuncture
[34] RCT	50 people with CTTH	Number of days per month with headache 3 months –8 days/month with laser acupuncture 0 days/month with placebo (machine set to 0 output power)	P <0.001 Similar significant differences reported at 1 and 2 months' follow-up (P <0.001)	Effect size not calculated	laser acupuncture
[34] RCT	50 people with CTTH	Headache duration 3 months –4 hours with laser acupuncture 0 hours with placebo (machine set to 0 output power)	P <0.001 Similar significant differences reported at 1 and 2 months' follow-up (P <0.001)	Effect size not calculated	laser acupuncture