Cerebral palsy among Asian ethnic subgroups.

OBJECTIVE: Asians have a reduced risk for cerebral palsy (CP) compared with whites. We examined whether individual Asian subgroups have a reduced risk of CP and whether differences in sociodemographic factors explain disparities in CP prevalence.
METHODS: In a retrospective cohort of 629 542 Asian and 2 109 550 white births in California from 1991 to 2001, we identified all children who qualified for services from the California Department of Health Services on the basis of CP. Asians were categorized as East Asian (Chinese, Japanese, Koreans), Filipino, Indian, Pacific Islander (Guamanians, Hawaiians, and Pacific Islanders), Samoan, or Southeast Asian (Cambodian, Laotian, Thai, Vietnamese).
RESULTS: Overall, CP prevalence was lower in Asians than whites (1.09 vs 1.36 per 1000; relative risk = 0.80, 95% confidence interval [CI] = 0.74-0.87) and ranged from 0.61/1000 in Thai children to 2.08/1000 in Samoan children. Several Asian subgroups had low risk profiles with respect to maternal age, educational attainment, and birth weight. However, after we adjusted for maternal age and education, infant gender, and birth weight, the adjusted risk of CP remained lower in East Asians (odds ratio [OR] = 0.75, 95% CI = 0.65-0.87), Filipinos (OR = 0.87, 95% CI = 0.75-0.99), Indians (OR = 0.59, 95% CI = 0.44-0.80), Pacific Islanders (OR = 0.62, 95% CI = 0.40-0.97), and Southeast Asians (OR = 0.68, 95% CI = 0.57-0.82) compared with whites.
CONCLUSIONS: Most Asian national origin subgroups have a lower rate of CP than whites, and this disparity is unexplained. Additional studies that focus on the cause of ethnic disparities in CP may provide new insights into pathogenesis and prevention.