title: Seasonal correlation and causal analysis of the incidence of bronchial foreign bodies in children.
abstract: OBJECTIVE
  To explore the seasonal correlation of the incidence of bronchial foreign body.
  
  
  METHODS
  Conduct retrospective analysis on clinical data of 1819 cases with bronchial foreign bodies in our hospital within an eight-year period (from January 2005 to January 2012), with cases classified into 12 groups by admission time (calculated by the Gregorian calendar in months, from January to December) and 4 groups by the Gregorian calendar in seasons (spring from March to May, summer from June to August, autumn from September to November, and winter from December to February), and observe whether the number of inpatients indicates any monthly or seasonal correlation.
  
  
  RESULTS
  The months of November and December indicated the highest number of inpatients, with 263 cases and 274 cases, which accounted for 12.7% and 13.2% of all reported cases, respectively. On the other hand, June and July had the lowest number of inpatients, with 96 cases and 75 cases, which accounted for 4.6% and 3.6%, respectively. Based on season, 749 cases were admitted in autumn, accounting for 35.1%; 636 cases were admitted in winter, accounting for 29.8%; 474 cases were admitted in spring, accounting for 22.2%; and 275 cases were admitted in summer, accounting for 12.9%. The number of inpatients was periodic, with 12 months as a cycle, and significant difference (P<0.01) was determined by comparing the numbers of inpatients in winter and spring and those in summer and spring.
  
  
  CONCLUSIONS
  The number of child in patients with bronchial foreign bodies is monthly periodic, with 12 months as a cycle, and respectively reaching the peak in November and December, and the valley in June and July; the seasonal characteristic was apparently related to the monthly characteristic, with the numbers of inpatients in autumn and winter each year being significantly higher than in the spring and summer, and the incidence showing apparent seasonal correlation. The results allow for the proposal of relevant precautionary measures against bronchial foreign bodies in children.
authors.affiliation: Otolaryngology of Qilu Children's Hospital of Shandong University, Jinan, Shandong 250022, China; Otolaryngology of Qilu Hospital of Shandong University, Jinan, Shandong 250022, China.
authors.forename: Sun
authors.initials: S
authors.lastname: Xiaowei
authors.affiliation: Otolaryngology of Qilu Children's Hospital of Shandong University, Jinan, Shandong 250022, China.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Jianji
authors.affiliation: Otolaryngology of Qilu Hospital of Shandong University, Jinan, Shandong 250022, China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Li
authors.affiliation: Otolaryngology of Qilu Hospital of Shandong University, Jinan, Shandong 250022, China.
authors.forename: Zhao Qiu
authors.initials: ZQ
authors.lastname: Liang
authors.affiliation: Otolaryngology of Qilu Hospital of Shandong University, Jinan, Shandong 250022, China. Electronic address: Shili126126@126.com.
authors.forename: Shi
authors.initials: S
authors.lastname: Li
authors.affiliation: Otolaryngology of Qilu Children's Hospital of Shandong University, Jinan, Shandong 250022, China.
authors.forename: Gai
authors.initials: G
authors.lastname: Zhongtao
authors.affiliation: Otolaryngology of Qilu Children's Hospital of Shandong University, Jinan, Shandong 250022, China.
authors.forename: Duan
authors.initials: D
authors.lastname: Chunhong
mesh_terms: D000293:Adolescent; D001980:Bronchi; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D005260:Female; D005547:Foreign Bodies / Q000453:epidemiology*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D012621:Seasons
keywords: Bronchial foreign body; Prevention; Season