Root Adrian, Brown Jeremy P, Forbes Harriet J, Bhaskaran Krishnan, Hayes Joseph, Smeeth Liam, Douglas Ian J
Electronic Health Records Group, London School of Hygiene and Tropical Medicine, London, United Kingdom.
UCL Division of Psychiatry, University College London, London, United Kingdom.
JAMA Pediatr. 2019 Nov 1;173(11):1068-1075. doi: 10.1001/jamapediatrics.2019.3194.
Young relative age within the school year has previously been associated with attention-deficit/hyperactivity disorder (ADHD) diagnosis and, based on limited evidence, diagnosis of intellectual disability. No study to date has examined the association between relative age and diagnosis of depression.
To estimate the associations with intellectual disability and ADHD and investigate a potential novel association between relative age and childhood depression.
DESIGN, SETTING, AND PARTICIPANTS: This population-based cohort study of 1 042 106 children aged 4 to 15 years used electronic record data collected before January 3, 2017, from more than 700 general practices contributing to the UK Clinical Practice Research Datalink. Multivariable Cox proportional hazards regression modeling was used to explore the association between relative age and the incidence of intellectual disability, ADHD, and depression before age 16 years. Data were analyzed between July 2017 and January 2019.
Relative age within school year determined by month of birth and categorized into four 3-month groups.
Intellectual disability, ADHD, and depression.
In the total cohort of 1 042 106 children, 532 876 were male (51.1%) and the median age at study entry was 4.0 years (interquartile range, 4.0-5.0). There was evidence that being born in the last quarter of the school year (ie, being the youngest group in a school year) was associated with diagnosis of intellectual disability (adjusted hazard ratio [aHR], 1.30; 95% CI, 1.18-1.42), ADHD (aHR, 1.36; 95% CI, 1.28-1.45), and depression (aHR, 1.31; 95% CI, 1.08-1.59) compared with being born in the first quarter. A graded association was seen with intermediate age groups at a smaller increased risk of each diagnosis compared with the oldest group, with aHRs for intellectual disability for those born in the second quarter of 1.06 (95% CI, 0.96-1.17) and for those born in the third quarter of 1.20 (95% CI, 1.09-1.32); aHRs for ADHD for those born in the second quarter of 1.15 (95% CI, 1.08-1.23) and for those born in the third quarter of 1.31 (95% CI, 1.23-1.40); and aHRs for depression for those born in the second quarter of 1.05 (95% CI, 0.85-1.29) and for those born in the third quarter of 1.13 (95% CI, 0.92-1.38).
In this study, relative youth status in the school year is associated with an increased risk of diagnosis of ADHD, intellectual disability, and depression in childhood. Further research into clinical and policy interventions to minimize these associations appears to be needed.
学年内相对年龄较小此前已与注意力缺陷多动障碍（ADHD）诊断相关，且基于有限证据，还与智力残疾诊断相关。迄今为止，尚无研究探讨相对年龄与抑郁症诊断之间的关联。
评估与智力残疾和ADHD的关联，并调查相对年龄与儿童期抑郁症之间潜在的新关联。
设计、背景和参与者：这项基于人群的队列研究纳入了1042106名4至15岁的儿童，使用了2017年1月3日之前从700多家参与英国临床实践研究数据链的全科诊所收集的电子记录数据。采用多变量Cox比例风险回归模型来探讨相对年龄与16岁之前智力残疾、ADHD和抑郁症发病率之间的关联。数据于2017年7月至2019年1月期间进行分析。
根据出生月份确定的学年内相对年龄，并分为四个3个月的组。
智力残疾、ADHD和抑郁症。
在1042106名儿童的总队列中，532876名是男性（51.1%），研究入组时的中位年龄为4.0岁（四分位间距，4.0 - 5.0）。有证据表明，与第一季度出生相比，在学年最后一个季度出生（即学年中最年幼的组）与智力残疾诊断（调整后风险比[aHR]，1.30；95%置信区间[CI]，1.18 - 1.42）、ADHD（aHR，1.36；95% CI，1.28 - 1.45）和抑郁症（aHR，1.31；95% CI，1.08 - 1.59）相关。与最年长组相比，中间年龄组每种诊断的风险增加较小，呈分级关联，第二季度出生者智力残疾的aHR为1.06（95% CI，0.96 - 1.17），第三季度出生者为1.20（95% CI，1.09 - 1.32）；第二季度出生者ADHD的aHR为1.15（95% CI，1.08 - 1.23），第三季度出生者为1.31（95% CI，1.23 - 1.40）；第二季度出生者抑郁症的aHR为1.05（95% CI，0.85 - 1.29），第三季度出生者为1.13（95% CI，0.92 - 1.38）。
在本研究中，学年内相对年幼状态与儿童期ADHD、智力残疾和抑郁症诊断风险增加相关。似乎需要进一步研究临床和政策干预措施以尽量减少这些关联。
