On 2016 Jul 24, JAVIER MATA commented:

Sorry not to have written before. We know that selection of an ES of 0.75 in the study establishes a stricter requirement to prove the efficacy of acupuncture than is used in the evaluation of NSAIDs. We used a higher effect size in order to improve the statistical power. A study without statistical significance does not necessarily mean that a relevant association does not exist between the factor under the study and the response. The statistical power of a study is determined by: the variability of the variables within the study, the size of the sample, the level of statistical significance and the effect size. The size of the effect on pain compared to sham acupuncture is 0.4 which is considered ‘moderate’ but the 95% CI around this estimate are wide (0.1, 0.6), this effect size was calculated with manual and electroacupuncture (EA). Use of EA was shown to be superior to manual stimulation alone for knee pain in 2010, but there is not effect size calculation with EA alone and from our experience it is higher.

On 2015 Jun 15, Arthur Yin Fan commented:

Why use Effect size 0.75? This is much higher than NIH recommended 0.50 for testing pain medication and higher than hinman's acupuncture trial for chronic knee pain (ES= 0.60).

On 2015 Jun 15, Arthur Yin Fan commented:

Why use Effect size 0.75? This is much higher than NIH recommended 0.50 for testing pain medication and higher than hinman's acupuncture trial for chronic knee pain (ES= 0.60).

On 2016 Jul 24, JAVIER MATA commented:

Sorry not to have written before. We know that selection of an ES of 0.75 in the study establishes a stricter requirement to prove the efficacy of acupuncture than is used in the evaluation of NSAIDs. We used a higher effect size in order to improve the statistical power. A study without statistical significance does not necessarily mean that a relevant association does not exist between the factor under the study and the response. The statistical power of a study is determined by: the variability of the variables within the study, the size of the sample, the level of statistical significance and the effect size. The size of the effect on pain compared to sham acupuncture is 0.4 which is considered ‘moderate’ but the 95% CI around this estimate are wide (0.1, 0.6), this effect size was calculated with manual and electroacupuncture (EA). Use of EA was shown to be superior to manual stimulation alone for knee pain in 2010, but there is not effect size calculation with EA alone and from our experience it is higher.