来自哥本哈根大学、普林斯顿大学、斯坦福大学和西北大学的四位经济学家基于丹麦1981年至2017年的全国卫生记录数据进行了深入研究，揭示了家庭中首子携带的传染病对幼子健康的重大影响。[1]研究发现，大宝从幼儿园带回的呼吸道疾病会显著增加二宝的住院风险。[1]具体而言，二宝在出生后头三个月因呼吸道疾病住院的概率为大宝的2到3倍。[1]
这一风险差异在二宝整个第一年中持续存在。[1]数据表明，每100个二宝中约有9.3个因呼吸道疾病在1岁内住过院，而大宝的这一比例仅为4.7个。[1]研究所涵盖的呼吸道疾病住院包括肺炎、支气管炎、呼吸道合胞病毒（RSV）感染等多种疾病。[1]这些早期住院经历可能对二宝的神经发育、长期心理健康和未来工作能力产生持续影响。[1]
A research team comprising economists from Copenhagen University, Princeton University, Stanford University, and Northwestern University has analyzed Denmark's national health and income data spanning 37 years to reveal the hidden health burden placed on second-born children.[1] The study, drawing on medical records from births between 1981 and 2017 in Denmark, found that respiratory illnesses contracted by older siblings in kindergarten significantly elevate the hospitalization risk for younger siblings.[1]
The findings are striking in their scope and severity. During the first three months of life, second-born children face a hospitalization risk from respiratory disease that is two to three times higher than that of first-born children.[1] By the end of their first year, approximately 9.3 out of every 100 second-born children have been hospitalized for respiratory illness, compared to just 4.7 of their first-born counterparts.[1] These respiratory conditions include pneumonia, bronchitis, and RSV infections, among others.[1]
The research suggests that these early health disparities may have long-term consequences for second-born children, potentially affecting their neurological development, long-term psychological health, and future work capacity.[1]
