Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway.
Int J Eat Disord. 2013 May;46(4):340-5. doi: 10.1002/eat.22060. Epub 2012 Oct 16.
Based on inconsistent findings in the literature, this study tested the hypothesis that "there is a season of birth bias for females with anorexia nervosa (AN)."
Females with AN, born in 1975 to 1996, were compared to females born in the same years and geographical regions by chi-square test for contingency tables with known population parameter testing for monthly deviations. Five groups were based on a priori power calculation and geographical location: Iceland, Norway and Sweden (N = 847), United Kingdom (N = 706), Oregon, USA (N = 394), Argentina and Brazil (N = 486), and Australia (N = 381).
The hypothesis was not supported in any of the groups. The associations (Cramér's V) between month of birth and the differences in distributions of births ranged from 0.05 to 0.08, none of which were statistically significant.
The main implication of these findings is that season of birth may not play a significant part in the aetiology of AN.
基于文献中不一致的发现，本研究检验了“厌食症女性存在出生季节偏倚（AN）”的假设。
通过卡方检验比较了出生于 1975 年至 1996 年的 AN 女性与同年同地理区域出生的女性，采用已知人口参数的列联表卡方检验测试月度偏差。根据先验功效计算和地理位置，将 5 组分为：冰岛、挪威和瑞典（N=847）、英国（N=706）、美国俄勒冈州（N=394）、阿根廷和巴西（N=486）以及澳大利亚（N=381）。
在任何组中，该假设均未得到支持。出生月份与出生分布差异之间的关联（Cramér's V）范围为 0.05 至 0.08，均无统计学意义。
这些发现的主要意义在于，出生季节可能在 AN 的发病机制中不起重要作用。
