Height inequalities and their change trends in China during 1985–2010: results from 6 cross-sectional surveys on children and adolescents aged 7–18 years

BACKGROUND Great health inequalities have been reported in China over the past few years. Height has been used as an important parameter of health and it may also be distributed unequally in different regions. By studying height data of Chinese children and adolescents aged 7 to 18 years, we analyze height inequalities and their change trends during 1985-2010. METHODS On the base of data from 6 successive cross-sectional surveys of the Chinese National Survey on Student's Constitution and Health(CNSSCH) conducted in 1985,1991,1995,2000,2005 and 2010, we calculated difference of height for children and adolescents aged 7-18 years in different regions. Coefficients of Variation (CVs) of height were computed in urban and rural areas during 1985-2010. RESULTS Great height difference existed between urban and rural, eastern and western, Shanghai and Guizhou children and adolescents aged 7-18 years. The urban-rural difference averagely decreased from 4.24 cm to 2.85 cm for boys and 3.72 cm to 1.31 cm for girls since 1985. Urban-rural difference tend to be more obvious in the poorer provinces, which has short mean statures. From 1985 to 2010, height difference became larger in eastern-western and Shanghai-Guizhou which represented the comparison between the richest and poorest regions. We also found there was a larger height inequality in rural areas compared with that in urban areas, and difference in rural subjects increased greater than their urban peers in eastern-western and Shanghai-Guizhou. CONCLUSIONS There were obvious height inequalities in China and the urban-rural difference narrowed, while increasing differences happened between regions with different socioeconomic levels especially in their rural residents. More attention should be paid to these differences and policies and strategies should be developed to reduce inequalities in height.