Norms and demographic differences of the Short Form-12 Health Survey version 2 in Chinese adolescents

Aim: This study aimed to establish the normative values for the 12-item Short Form Health Survey version 2 (SF-12v2) and examine demographic differences among Hong Kong Chinese adolescents. Methods: A total of 28 981 Hong Kong Chinese adolescents aged 12-18 participated in a school-based survey in 2006-2007. Sex- and age-specific SF-12v2 scores were obtained. Ordinal logistic regression models and linear regression models were used to examine the demographic differences for the eight subscales including physical functioning, role physical, bodily pain, general health, vitality, social functioning, role emotional and mental health, and two component summary scores of Physical Component Summary and Mental Component Summary. Results: The mean (standard deviation) Physical Component Summary score was 50.28 (6.82) for boys and 49.37 (6.47) for girls. The corresponding Mental Component Summary score was 45.86 (9.86) for boys and 44.77 (9.56) for girls. Ceiling effects were observed in some of the eight subscales but not the two component summary scores. Ordinal logistic regression showed that girls had significantly lower scores than boys in most subscales including physical functioning with odds ratio (95% confidence interval) of 0.89 (0.84-0.93); role physical, 0.94 (0.90-0.98); bodily pain, 0.76 (0.73-0.80); general health, 0.55 (0.53-0.57); vitality, 0.72 (0.69-0.75); role emotional, 0.78 (0.74-0.81); and mental health, 0.91 (0.88-0.95). In general, older and non-local-born adolescents had lower component summary scores than their peers. Conclusions: This study has provided norms and identified demographic differences of the Chinese SF-12v2.