Douglas A S, Gupta R, Helms P J, Jolliffe I T
Department of Medicine and Therapeutics, University of Aberdeen, Scotland, UK.
Paediatr Perinat Epidemiol. 1997 Jan;11(1):57-66. doi: 10.1046/j.1365-3016.1997.d01-8.x.
Well-known epidemiological features of sudden infant death syndrome (SIDS) are age at death and the increased numbers in winter. There are more SIDS deaths in late autumn/early winter and there is a seasonal rhythm of births with a peak in late summer and early autumn. The data set was 14033 SIDS deaths from Scotland, England and Wales over the 11 years 1982-92. Using log-linear models, which accounted for age at death and month of death, birth month was found to be a statistically significant risk factor for SIDS independent of age at death and winter environment (P < 0.001). Although winter season had the largest effect (relative risk 2.7 in January compared with August), the independent effect of birth month was of clinical as well as statistical significance with a relative risk for August births of 1.37 compared with those born in April. The analysis of each birth month cohort revealed a change in age distribution with infants born in early winter (December) dying at a younger age (mean 108 days) than those born in midsummer (June) (mean 146 days). Although winter season and age are the most influential factors, the substantial effect of month of birth requires explanation and points to as yet unidentified environmental influences during pregnancy.
婴儿猝死综合征（SIDS）广为人知的流行病学特征是死亡年龄以及冬季死亡人数的增加。深秋/初冬的婴儿猝死综合征死亡病例更多，并且存在季节性的出生节奏，夏末和初秋出生人数达到峰值。该数据集涵盖了1982年至1992年这11年间苏格兰、英格兰和威尔士的14033例婴儿猝死综合征死亡病例。使用对数线性模型，该模型考虑了死亡年龄和死亡月份，结果发现出生月份是婴儿猝死综合征的一个具有统计学意义的风险因素，与死亡年龄和冬季环境无关（P < 0.001）。尽管冬季的影响最大（1月份的相对风险为2.7，而8月份为1），但出生月份的独立影响在临床和统计学上均具有显著意义，8月份出生婴儿的相对风险为1.37，而4月份出生的婴儿为参照。对每个出生月份队列的分析显示，年龄分布存在变化，初冬（12月）出生的婴儿死亡年龄（平均108天）比仲夏（6月）出生的婴儿（平均146天）要小。尽管冬季和年龄是最具影响力的因素，但出生月份的显著影响仍需要解释，这表明孕期存在尚未明确的环境影响因素。
