Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Symptom severity
[33] Systematic review	People with TTH and CTTH diagnosed using IHS criteria[17] Data from 1 RCT	Proportion of responders 3–4 months after randomisation 60/132 (45%) with acupuncture 3/74 (4%) with no acupuncture	RR 11.36 95% 3.69 to 34.98 P value not reported	Moderate effect size	acupuncture
[33] Systematic review	People with episodic TTH and CTTH diagnosed using IHS criteria[17] Data from 1 RCT	Mean number of headache days 3–4 months after randomisation 9.9 with acupuncture 16.3 with no acupuncture	MD –6.40 95% CI –8.81 to –3.99 P value not reported	Effect size not calculated	acupuncture
[33] Systematic review	People with episodic TTH and CTTH diagnosed using IHS criteria[17] Data from 1 RCT	Mean headache intensity 3–4 months after randomisation 2.9 with acupuncture 4.6 with no acupuncture	SMD –1.08 95% CI –1.41 to –0.76 P value not reported	Effect size not calculated	acupuncture
[33] Systematic review	People with episodic TTH and CTTH diagnosed using IHS criteria[17] Data from 1 RCT	Mean headache score 3–4 months after randomisation 15.8 with acupuncture 26.4 with no acupuncture	SMD –0.71 95% CI –1.02 to –0.39 P value not reported	Effect size not calculated	acupuncture