Prevalence, Risk Factors, Impact and Management of Pneumonia Among Preschool Children in Chinese Seven Cities: A Cross-Sectional Study with Interrupted Time Series Analysis

Abstract

Background: Preschool children are common carriers of pneumonia, and exploring possible risk factors for pneumonia in children is warranted. Here, we investigated the prevalence of pneumonia among preschool children in seven representative cities in China and explored possible risk factors.

Methods: Two group samples of 63663 and 52812 preschool children were recruited from 2011 and 2019 surveys, respectively. Which were derived from the crosssectional China, Children, Homes, Health (CCHH) study using a multi-stage stratified sampling method. This survey was conducted in kindergartens in seven representative cities. Exclusion criteria were younger than 2 years old or older than 8 years old, nonpermanent population, basic information such as gender, date of birth and breast feeding is incomplete. Pneumonia was determined on the basis of parents reported history of clearly diagnosed by the physician. All participants were assessed with a standard questionnaire. Risk factors for pneumonia, and association between pneumonia and other respiratory diseases were examined by multivariable-adjusted analyses done in all participants for whom data on the variables of interest were available. Disease management was evaluated by the parents reported history of physician diagnosis, longitudinal comparison of risk factors in 2011 and 2019.

Findings: In 2011 and 2019, 31277 (16152 boys and 15125 girls) and 32016 (16621 boys and 15395 girls) preschool children aged at 2-8 of permanent population completed the questionnaire, respectively, and were thus included in the final analysis. The findings showed that the age-adjusted prevalence of pneumonia in children was 32.7% in 2011. Previous pneumonia was reported at least one time in 62.2% (95% CI 60.3-64.1) of children with asthma, 47.6% (95% CI 45.9-49.4) of children with rhinitis, or 47.1% (95% CI 46.0-48.2) of children with wheeze. Girls (odds ratio [OR] 0.91, 95%CI 0.87-0.96; p=0.0002), Rural (0.85, 0.73-0.99; p=0.0387), Duration of breastfeeding ≥ 6 months(0.83, 0.79-0.88; p＜0.0001), Birth weight (g)≥4000 (0.88, 0.80-0.97; p=0.0125), Frequency of putting bedding to sunshine (Often) (0.82, 0.71-0.94; p=0.0049), Cooking fuel type (Electricity) (0.87, 0.80-0.94; p=0.0005), Indoor use air-conditioning (0.85, 0.80-0.90; p＜0.0001) were associated with a reduced risk of childhood pneumonia. Age (4-6) (1.11, 1.03-1.20; p=0.0052), Parental smoking (one) (1.12, 1.07-1.18; p＜ 0.0001), Used antibiotics (2.71, 2.52-2.90; p＜0.0001), History of parental allergy (one and two) (1.21, 1.12- 1.32; p＜0.0001 and 1.33, 1.04-1.69; p=0.0203), Indoor dampness (1.24, 1.15-1.33; p ＜ 0.0001), Home interior decoration (1.11, 1.04-1.19; p=0.0013), Wall painting materials (Paint) (1.16, 1.04-1.29; p=0.0084), Flooring materials (Laminate / Composite wood) (1.08, 1.02-1.16; p=0.0126), Indoor heating mode (Central heating) (1.18, 1.07-1.30, p=0.0090), Asthma (2.38, 2.17-2.61; p＜0.0001), Allergic rhinitis (1.36, 1.25-1.47; p＜0.0001), Wheezing (1.64, 1.55-1.74; p＜0.0001) were associated with an elevated risk of childhood pneumonia. The age-adjusted prevalence of pneumonia in children was 26.4% in 2019. Previous pneumonia was reported at least one time in 59.5% (95%CI 56.6-62.2) of children with asthma, 44.1% (95%CI 42.5-45.7) of children with rhinitis, or 57.3% (95%CI 55.2-59.4) of children with wheeze. Girls (0.92, 0.87-0.97; p=0.0019), duration of breastfeeding ≥6 months (0.92, 0.87-0.97; p=0.0031), used antibiotics (0.22, 0.21-0.24; p＜0.0001), cooking fuel type (Other) (0.40, 0.23-0.63; p=0.0003), indoor use air-conditioning (0.89, 0.83- 0.95; p=0.0009) were associated with a reduced risk of childhood pneumonia. Urbanisation (Suburb) (1.10, 1.02-1.18; p=0.0093), premature birth (1.29, 1.08-1.55; p=0.0051), birth weight (g)＜ 2500 (1.17, 1.02-1.35; p=0.0284), parental smoking (1.30, 1.23-1.38; p＜ 0.0001), history of parental asthma (One) (1.23, 1.03-1.46; p=0.0202), history of parental allergy（one and two）(1.20, 1.13-1.27; p＜0.0001 and 1.22, 1.08-1.37; p=0.0014), cooking fuel type (Coal) (1.58, 1.02-2.52; p=0.0356), indoor dampness (1.16, 1.08-1.24; p＜0.0001), asthma (1.88, 1.64-2.15; p＜0.0001), allergic rhinitis (1.57, 1.45-1.69; p＜0.0001), wheezing (2.43, 2.20-2.68; p＜0.0001) were associated with an elevated risk of childhood pneumonia.

Interpretation: Pneumonia is prevalent among preschool children in China, and it affects other childhood respiratory diseases. Although the prevalence of pneumonia in Chinese children shows a decreasing trend in 2019 compared to 2011, a wellestablished management system is still needed to further reduce the prevalence of pneumonia and reduce the burden of disease in children.

Funding Information: This work was supported by the National Natural Science Foundation of China (grant no. 81860179 and 81861138005).

Declaration of Interests: We declare no competing interests.

Ethics Approval Statement: The study was conducted strictly in accordance with the Declaration of Helsink i and approved by the research ethics committee of Fudan University (protocol no. IRB00002408 & FWA00002399), all parents and class teachers of the child ren under investigation have signed written informed consent.

Keywords: pneumonia, preschool children, risk factors