Center for Health Policy, Duke Global Health Institute, Durham, NC 27705, USA.
Ann Epidemiol. 2010 Jan;20(1):32-9. doi: 10.1016/j.annepidem.2009.09.006.
The etiology of orofacial clefts is complex and relatively unknown. Variation in cleft lip with or without palate (CLP) and cleft palate alone (CP) was examined in Texas across urban-rural residence (1999 to 2003).
Cases came from the Texas Birth Defects Registry (1,949 CLP and 1,054 CP) and denominator data came from vital records (254 counties; 1,827,317 live births). Variation in maternal residence was measured using four classification schemes: Rural Urban Continuum Codes, Urban Influence Codes, percentage of county in cropland, and Rural Urban Commuting Areas. Poisson regression was used to calculate rate ratios, adjusted for infant sex, plurality, gestational age, maternal parity, age, race/ethnicity, and education.
Compared to the most urban referent category, living in more rural areas was associated with an increased adjusted risk of CLP. For example, the Rural-Urban Continuum Codes demonstrated elevated risks for CLP in "thinly populated areas" compared to "metropolitan-urban areas" (adjusted prevalence ratio = 1.9; 95% confidence intervals (CI) 1.2-2.8); CP was not similarly associated. Percentage of county cropland was not consistently associated with any outcome.
The association patterns between non-urban residence and risk of CLP, except for percentage of cropland, suggests a constellation of exposures that may differ across urban-rural residence.
口面裂的病因复杂且相对未知。本研究在德克萨斯州，对唇裂伴或不伴腭裂（CLP）和单纯腭裂（CP）的城乡居住差异进行了研究（1999 年至 2003 年）。
病例来自德克萨斯州出生缺陷登记处（1949 例 CLP 和 1054 例 CP），而分母数据来自生命统计数据（254 个县；1827317 例活产）。采用四种分类方案来衡量母体居住地的差异：城乡连续体代码、城市影响力代码、耕地比例和城乡通勤区。采用泊松回归计算率比，调整婴儿性别、多胎妊娠、胎龄、母亲产次、年龄、种族/民族和教育等因素。
与最城市化的参考类别相比，居住在更农村地区与 CLP 调整后风险增加相关。例如，与“大都市-城市地区”相比，“人口稀少地区”的农村-城市连续体代码显示出 CLP 的风险升高（调整后流行率比=1.9；95%置信区间（CI）1.2-2.8）；CP 则没有类似的关联。县耕地比例与任何结果均无一致关联。
除耕地比例外，非城市居住与 CLP 风险之间的关联模式表明，在城乡居住差异下，可能存在一系列不同的暴露因素。
