Co-Occurrence of Health Conditions during Childhood: Longitudinal Findings from the UK Millennium Cohort Study (MCS)

Aims
To identify patterns of stability and change in co-occurrence in children between 5–11 years, and to assess if they vary by socio-demographic factors.
Methods
Data from 9548 singleton children from the UK Millennium Cohort Study (MCS) were assessed for co-occurrence of five common adverse conditions: wheeze; longstanding illness; unfavorable weight; injury; and socio-emotional difficulties. We summed adverse conditions (0–5) for each child at ages 5, 7, and 11 and identified co-occurrence (≥2 conditions). Using multinomial regression, we explored associations between co-occurrence trajectories and child’s sex and ethnicity, maternal education, and income quintile.
Results
45.6% of children experienced co-occurrence between 5–11 years (7% experienced constant co-occurrence). More children moved into co-occurrence than moved out (16.9 vs. 11.9%). Mutually-adjusted relative risk ratios (aRRR) showed a gradient by maternal education: compared to children with no co-occurrence whose mothers had a higher/degree, children whose mothers had no qualifications were more likely to move into (aRRR = 1.32(95%CI:1.02,1.70)), out of (1.74(1.34,2.26)), have fluctuating (1.52(1.09,2.10)) or constant co-occurrence (2.58(1.76,3.80)). The same gradient (high vs. low) was evident for income quintiles. Girls were less likely to experience co-occurrence.
Conclusions
Co-occurrence of adverse conditions is common during childhood, and trajectories are socially patterned. Child-focused care for lower-income children and boys early in life may prevent and reduce co-occurrence in later childhood.

研究目的：旨在明确5至11岁儿童不良状况共现（co-occurrence）的稳定与变化模式，并探究其是否随社会人口学因素而存在差异。
研究方法：本研究纳入英国千禧世代队列研究（Millennium Cohort Study, MCS）中的9548名单胎儿童，对其5种常见不良状况的共现情况进行评估，这5种状况分别为：喘息、长期疾病、体重异常、损伤以及社会情绪困难。我们分别在儿童5岁、7岁及11岁时对每名儿童的不良状况进行计数（计数范围为0至5项），并将同时存在≥2项不良状况界定为共现情况。本研究采用多项回归分析，探究不良状况共现轨迹与儿童性别、种族、母亲受教育程度以及收入五分位组之间的关联。
研究结果：45.6%的儿童在5至11岁期间出现不良状况共现，其中7%为持续共现。从无共现进展为共现的儿童比例（16.9%）高于从共现转为无共现的比例（11.9%）。校正后相对风险比（mutually-adjusted relative risk ratios, aRRR）显示，母亲受教育程度存在梯度效应：以母亲拥有高等教育或学位且儿童无共现的群体为参照，母亲无任何学历资格的儿童，其转为共现（aRRR=1.32，95%CI：1.02~1.70）、脱离共现状态（aRRR=1.74，95%CI：1.34~2.26）、出现波动型共现（aRRR=1.52，95%CI：1.09~2.10）以及持续共现（aRRR=2.58，95%CI：1.76~3.80）的风险均更高。收入五分位组同样呈现高收入与低收入群体间的梯度效应。女孩出现不良状况共现的概率更低。
研究结论：儿童期不良状况共现现象较为普遍，其共现轨迹存在社会分布差异。对低收入家庭儿童与男童开展早期以儿童为中心的照护，或可预防并降低其童年后期出现不良状况共现的风险。