Pain response in Chinese and non-Chinese Canadian infants: is there a difference?

This study was designed to compare the behavioural pain responses of 2-month-old Canadian-born Chinese babies receiving a routine immunization to those of non-Chinese infants in similar situations. Two groups of 26 infants were obtained from a pediatric clinic held by a Chinese pediatrician and a suburban pediatric practice of a large Canadian city. Facial expression using the Neonatal Facial Coding System (Grunau, R.V.E., Craig, K.D., 1987. Pain expression in neonates: facial action and cry. Pain, 28, 395–410.) and cry using the Fast Fourier Transform were measured during 30 s following the insertion of the needle. Acculturation in Chinese mothers, circadian rhythm, gender, height and weight in infants were assessed. Multivariate analysis of variance revealed significant differences in pain response between these two groups with the Chinese babies showing greater response. No significant effect of circadian rhythm and gender was identified. These results suggest the presence of differences in acute pain response in relation to culture by at least 2 months of age.