The Effect of a Combination of Vibration and External Cold on Pain Caused during Vaccine Injection in Infants: A Randomized Clinical Trial

Table 2

Comparison of mean pain intensity and duration of crying in study groups.

Group	Intervention group (n = 40)	Control group (n = 40)	Test results	Effect size
	Mean ± SD	Mean ± SD
Intensity of pain	6.1 ± 1.8	7.0 ± 2.1	; z = −2.1^a	0.46
Crying duration (seconds)	32.47 ± 16.7	51.02 ± 25.9	; t = 3.8^b	0.85

^aMann–Whitney test. ^bIndependent t-test.