Table 1

search strategy used in medline database

no.search items
#1randomized controlled trial [pt]
#2controlled clinical trial [pt]
#3randomized [tiab]
#4placebo [tiab]
#5clinical trials [mesh]
#6randomly [tiab]
#7trial [ti]
#8#1 or #2 or #3 or #4 or #5 or #6 or #7
#9humans [mesh]
#10#8 and #9
#11headache disorders [mesh]
#12headache [mesh]
#13(headache or migraine or cephalgia or cephalalgia or chronic migraine): ti,ab
#14#11 or #12 or #13
#15acupuncture therapy [mesh]
#16(acupuncture or body acupuncture or manual acupuncture or electroacupuncture or electro-acupuncture or auricular acupuncture or laser acupuncture or warm needling): ti,ab
#17#15 or #16
#18#10 and #14 and #17