Multimorbidities of asthma, allergies, and airway illnesses in childhood: Chance or not chance?

ABSTRACT

Objectives: We investigated patterns of multimorbidities among asthma, allergies, and respiratory illnesses in preschool children. We investigated multimorbidities of lifetime asthma, allergic rhinitis, eczema, food allergy, pneumonia, and ear infections; and multimorbidities of current (in the last year before the survey) wheeze, dry cough, rhinitis, eczema, and common cold during childhood. We further analyzed whether prevalences of these multimorbidities were due to chance. Methods: A cross-sectional study was conducted in 72 kindergartens of Shanghai, China. Parents of preschool children were surveyed with a modified ISAAC questionnaire. Observed prevalences (OPs), expected prevalences (EPs), absolute excess comorbidities (AECs), and relative excess comorbidities (RECs) of various combinations of illnesses were calculated to indicate whether the combined illnesses were related. Results: We analyzed questionnaires for children aged 4–6 years, whose 13,335 questionnaires were the majority of the total 15,266 returned questionnaires (response rate: 85.3%). The studied illnesses were common. For children who had more than three lifetime or current illnesses, OPs tended to be higher than EPs. Most OPs and EPs were higher in boys than in girls, and were higher in children with a family history of atopy (FHA) than in children without FHA. AECs and RECs between boys and girls as well as between children with and without FHA were substantially different. Conclusions: Our findings suggest that multimorbidities among childhood asthma, allergies, and respiratory illnesses are likely not random, but rather share etiology. Specific patterns of childhood asthma multimorbidities perhaps differ between boys and girls and between children with and without FHA.

KEYWORDS:

• Asthma
• rhinitis
• eczema
• co-existence
• children
• China
• multimorbidity

Acknowledgements

The authors thank Shanghai Municipal and District Bureau of Education for their supports and greatly appreciate Prof. Yinping Zhang (Tsinghua University) and Prof. Baizhan Li (Chongqing University) in guidance of the national CCHH project, Associate Prof. Yuexia Sun (Tianjin University) in preparing the questionnaire, and Associate Prof. Zhuohui Zhao (Fudan University) in obtaining the ethical approval for CCHH project. We also greatly appreciate all parents and children who participated in the survey.

Declaration of interests

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Funding

This study is financially supported by the National Natural Science Foundation of China (51278302), Innovation Program of Shanghai Municipal Education Commission (14ZZ132), Hujiang Foundation of China (D14003), and the Innovation Fund Project for Graduate Student of Shanghai (JWCXSL1401). The funder provided support in the form of expenditures for authors, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of the authors are articulated in the authors' contributions section.