Fig. 4From: Trends and quality of randomized controlled trials on acupuncture conducted in Japan by decade from the 1960s to the 2010s: a systematic reviewProportion of positive RCTs stratified by decade. Only randomized controlled trials (RCTs) with control groups of sham/conventional/no treatment were included in this analysis. Some RCTs were counted more than once because they had more than one control group (see Table 1)Back to article page