Matsuda S, Kahyo H
Department of Preventive Medicine and Community Health, University of Occupational and Environmental Health, Kitakyushu, Japan.
Hum Biol. 1998 Oct;70(5):919-35.
Based on vital statistics from 1979 to 1983, we used a time-series analysis using the Box-Jenkins model (ARIMA model) to compare the seasonality of preterm births among 47 prefectures in Japan. We also evaluated the relation between seasonality of preterm births and temperature. According to the Box-Jenkins analysis, a seasonal moving average was detected for 44 prefectures. The seasonality of preterm births in general shows a bimodal pattern with two peaks, one in summer and one in winter. The most interesting result is that the peaks show a trend with geographic location; one peak is dominant in winter among the northern prefectures and the other peak is dominant in summer among the southern prefectures. Another important result is that the winter increase in preterm births is negatively correlated with mean winter temperature (R = -0.424, p = 0.003); on the contrary, the summer increase in preterm births is positively correlated with the average summer temperature (R = 0.549, p < 0.001). These results suggest that climate-associated factors should be associated with the occurrence of preterm births in Japan.
基于1979年至1983年的人口动态统计数据，我们采用Box-Jenkins模型（自回归积分滑动平均模型）进行时间序列分析，以比较日本47个县早产的季节性特征。我们还评估了早产季节性与温度之间的关系。根据Box-Jenkins分析，在44个县检测到季节性移动平均值。早产的季节性总体上呈现双峰模式，有两个峰值，一个在夏季，一个在冬季。最有趣的结果是，这些峰值呈现出随地理位置变化的趋势；在北部各县中，一个峰值在冬季占主导，而在南部各县中，另一个峰值在夏季占主导。另一个重要结果是，冬季早产的增加与冬季平均温度呈负相关（R = -0.424，p = 0.003）；相反，夏季早产的增加与夏季平均温度呈正相关（R = 0.549，p < 0.001）。这些结果表明，与气候相关的因素可能与日本早产的发生有关。
