Background: Rates of rickets from 15.9 to 26.7% have been reported in China.
Methods: Combining the methods of epidemiology and the behavioral sciences, this study investigated the prevalence of rickets in children in rural Shanxi Province, China. A total of 250 children age 12-24 months were examined physically for the presence of rickets, blood was drawn for laboratory analysis, and X-rays were taken of each child's wrists.
Results: Vitamin D deficiency in the spring was found among 65.3% of children. Rickets diagnosis relying on clinical signs alone determined a rickets prevalence of 41.6%, declining to 17.0% in the fall after a summer of sun exposure (chi(2) = 8.356, P = 0.004). But an integrated diagnostic method exploiting clinical signs, X-ray and alkaline phosphatase levels found the prevalence of active rickets to be 3.7%. Furthermore, it was demonstrated that only five clinical signs reflect active rickets--wide wrists, frontal bossing, rachitic rosary, Harrison's sulcus, and bowed legs.
Conclusions: The prevalence of active rickets in young children in northern China is lower than previously reported. Even in poor countries, simple tests such as X-rays and alkaline phosphatase can be added to physical examination to more accurately diagnose active rickets.