Pediatric Ambulatory Community Clinic, Petach Tikva, Israel;
Pediatrics. 2014 Apr;133(4):e923-32. doi: 10.1542/peds.2013-2022. Epub 2014 Mar 10.
Seasonal variations in asthma are widely recognized, with the highest incidence during September. This retrospective population study aimed to investigate whether this holds true in a large group of asthmatic children in primary care and to assess the impact of age, gender, urban/rural living, and population sector.
The key study outcomes were the diagnosis of asthma exacerbations and asthma medication prescriptions, recorded by family physicians during 2005 to 2009. These were analyzed by "week of diagnosis" in Clalit Health Services' electronic medical record database. Regression models were built to assess relative strength of secular trends, seasonality, and age-group in explaining the incidence of asthma exacerbations.
A total of 919,873 children aged 2 to 15 years were identified. Of these, 82,234 (8.9%) were asthmatic, 61.6% boys and 38.4% girls; 49.1% aged 2 to 5 years, 24.1% 6 to 9 years, and 26.8% 10 to 15 years. We observed a 2.01-fold increase in pediatric asthma exacerbations and 2.28-fold increase in prescriptions of asthma bronchodilator medications during September (weeks 37-39 vs weeks 34-36) compared with August. The association between the opening of school and the incidence of asthma-related visits to the primary care physician was greatest in children aged 2 to 5 years (odds ratio, 2.15) and 6 to 11 years (1.90-fold). Adolescents (age 12-15 years) had a lesser peak (1.81-fold). In late fall there was a second rise, lasting with fluctuations throughout winter, with a trough in summer.
Returning to school after summer is strongly associated with an increased risk for asthma exacerbations and unscheduled visits to the primary care physician.
哮喘的季节性变化是广泛公认的，其发病率在 9 月最高。本回顾性人群研究旨在调查这一现象在大量初级保健哮喘儿童中是否成立，并评估年龄、性别、城乡居住和人口群体的影响。
主要研究结果是家庭医生在 2005 年至 2009 年期间记录的哮喘加重和哮喘药物处方的诊断。这些诊断通过 Clalit 医疗保健服务的电子病历数据库中的“诊断周”进行分析。回归模型用于评估季节性、年龄组在解释哮喘加重发生率方面的相对强度。
共确定了 919873 名 2 至 15 岁的儿童。其中，82234 名（8.9%）患有哮喘，男孩占 61.6%，女孩占 38.4%；49.1%为 2 至 5 岁，24.1%为 6 至 9 岁，26.8%为 10 至 15 岁。与 8 月相比，我们观察到 9 月（第 37-39 周）儿童哮喘发作增加了 2.01 倍，哮喘支气管扩张剂药物处方增加了 2.28 倍。学校开学与初级保健医生就诊的哮喘相关就诊的发病率之间的关联在 2 至 5 岁（优势比，2.15）和 6 至 11 岁（1.90 倍）的儿童中最大。青少年（12-15 岁）的峰值较小（1.81 倍）。在深秋会出现第二次上升，持续波动到冬季，夏季则达到低谷。
暑假后返校与哮喘加重和非计划就诊的风险增加密切相关。
