title: Smoke-free legislation reduces hospital admissions for childhood lower respiratory tract infection.
abstract: Previous studies showed reduction of hospital admissions for asthma after implementation of comprehensive smoke-free legislation. We aimed to evaluate the impact of comprehensive smoke-free legislation implemented in Hong Kong in 2007 on hospital admissions for childhood lower respiratory tract infection (LRTI).
  
  
  
  We obtained data on 75 870 hospital admissions for LRTI among children ≤18 years of age between January 2004 and December 2012 from all Hospital Authority hospitals. Using a negative binomial regression model, we assessed the impact of smoke-free legislation on admission counts.
  
  
  
  After legislation implementation, there was an immediate effect with a change in the admission count of -33.5% (95% CI -36.4% to -30.5%), and a change in time trend to -13.9% per year (95% CI -16.0% to -11.7%). Overall, the legislation was associated with a net 47.4% reduction in admission counts in the first year. We estimated that the legislation was associated with a reduction of 13 635 admissions in the first 6 years after implementation. The immediate reduction and change in time trend was more apparent among school-age than preschool children.
  
  
  
  Implementation of comprehensive smoke-free legislation was associated with a significant reduction in hospital admissions for childhood LRTI.
authors.affiliation: Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: So Lun
authors.initials: SL
authors.lastname: Lee
authors.affiliation: Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: Wilfred Hing Sang
authors.initials: WH
authors.lastname: Wong
authors.affiliation: Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China.|The University of Hong Kong, Shenzhen Hospital, Shenzhen, Guangdong, China.
authors.forename: Yu Lung
authors.initials: YL
authors.lastname: Lau
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000393:Air Pollutants / Q000009:adverse effects / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D006723:Hong Kong / Q000453:epidemiology; D006760:Hospitalization / Q000706:statistics & numerical data* / Q000639:trends; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D010343:Patient Admission / Q000706:statistics & numerical data; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000209:etiology; D061845:Smoke-Free Policy / Q000331:legislation & jurisprudence*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects / Q000331:legislation & jurisprudence / Q000517:prevention & control; D014887:Weather
chemical_list: D000393:Air Pollutants; D014028:Tobacco Smoke Pollution
keywords: Environment; Prevention; Public policy; Secondhand smoke