University of Sussex, Brighton, UK.
University College London, London, UK.
Int J Epidemiol. 2024 Aug 14;53(5). doi: 10.1093/ije/dyae119.
Despite persistent concerns about only children's disadvantage relative to individuals with siblings, existing health-related evidence is inconsistent. Recent evidence from Nordic countries about only children having poorer health outcomes may not apply elsewhere because selection processes differ across contexts. We investigate the midlife health of only children in the UK where one-child families tend to be socio-economically advantaged relative to large families.
Using the 1946, 1958 and 1970 British birth cohort studies, we examine various biomarkers and self-reported measures of chronic disease by sibship size when respondents are aged in their mid-40s, mid-50s and mid-60s. We estimate separate linear probability models for each cohort, age and outcome, adjusting for childhood and early adulthood circumstances.
We found no evidence of only children differing from those with one, two or three or more siblings, at any age, in any of the cohorts, on: heart problems, hypertension, high triglycerides, high glycated haemoglobin or high C-reactive protein. However, compared with only children, the probability for cancer (0.019, 95% confidence interval [CI]: 0.002, 0.035; age 46/1970) and poor general health (0.060, CI: 0.015, 0.127; age 55/1958; and 0.110, CI: 0.052, 0.168; age 63/1946) was higher among those with three or more siblings.
There is no consistent pattern of only child health disadvantage for midlife chronic disease outcomes across ages or cohorts in the UK. Research should focus on better understanding how sibship size differentials are contingent on context.
尽管人们一直担心独生子女性别相对于有兄弟姐妹的人存在劣势，但现有的健康相关证据并不一致。北欧国家最近的证据表明，独生子女性健康状况较差，但这些证据可能不适用于其他地区，因为不同的环境下存在不同的选择过程。我们在英国调查了独生子女性健康状况，在英国，相对于大家庭，一孩家庭往往在社会经济方面具有优势。
我们使用了 1946 年、1958 年和 1970 年的英国出生队列研究，当受访者年龄在 40 多岁、50 多岁和 60 多岁时，我们根据兄弟姐妹的数量检查了各种生物标志物和慢性疾病的自我报告测量结果。我们为每个队列、年龄和结果分别估计了线性概率模型，并调整了童年和成年早期的情况。
我们发现，在任何年龄、任何队列中，独生子女性别与那些有一个、两个或三个或更多兄弟姐妹的人在心脏问题、高血压、高甘油三酯、高糖化血红蛋白或高 C 反应蛋白方面没有差异。然而，与独生子相比，有三个或更多兄弟姐妹的人患癌症（0.019，95%置信区间 [CI]：0.002，0.035；年龄 46/1970）和总体健康状况较差（0.060，CI：0.015，0.127；年龄 55/1958；0.110，CI：0.052，0.168；年龄 63/1946）的可能性更高。
在英国，不同年龄或队列的独生子女性别在中年慢性疾病结局方面没有一致的健康劣势模式。研究应侧重于更好地了解兄弟姐妹数量的差异如何取决于背景。
