TABLE 4.

Credibility of blinding.

	Treatment guess, No. (%)	Acupuncture group (n = 80a)	Medication group (n = 77b)	Kappa Coefficient (95% CI)	P c
Cycle 1.5	True acupuncture plus placebo naproxen	61 (76.2%)	53 (68.8%)	0.075 (−0.07, 0.22)	0.30
	Sham acupuncture plus naproxen	19 (23.8%)	24 (31.2%)
Cycle 3	True acupuncture plus placebo naproxen	62 (77.5)	49 (63.6%)	0.14 (−0.00, 0.28)	0.06
	Sham acupuncture plus naproxen	18 (22.5%)	28 (36.4%)

^aSix participants in the acupuncture group were not recorded at Cycles 1.5 and 3 because they dropped out.

^bSeven participants in the medication group were not recorded at Cycles 1.5 and 3 because they dropped out.

^cP was calculated from a kappa analysis.

CI, confidence interval.