{
  "abstract": "Background Second-hand tobacco smoke (SHS) is associated with adverse health outcomes in children, including wheezing and asthma. Current United Kingdom (UK) legislation prohibits smoking in enclosed public and work-spaces, but many children remain exposed to SHS in their homes. We hypothesised that children sharing households with adult smokers were more likely to have current asthma, after accounting for child age, sex, ethnic group and household overcrowding.Methods We linked the primary electronic health care records (EHR) of children 7–17 years, currently registered with all general practices in North East London, UK on 21st March 2021, to property data using pseudonymised address identifiers, Unique Property Reference Numbers (pUPRNs). We defined a household as people living at the same pUPRNs on the study date. The primary outcome was current asthma defined as children coded in the EHR with an asthma diagnosis and with asthma medication prescribed within 12 months before the study date. We created an overcrowding measure based on household space (m 2) per person. We developed in RStudio logistic regression models accounting for within-household correlation, to estimate the adjusted odds ratios (aOR) and 95% confidence intervals (CI) of current childhood asthma in a smoking household with at least one adult (≥26 years) smoker, adjusting for child age, sex, and ethnic group, and household overcrowding.Results The study sample comprised 90,387 children who lived in 55,965 households with 118,543 adults, of whom 28,313 (23.9%) were coded in EHRs as current smokers and 84,342 (71.1%) as ex-smokers or non-smokers within seven years before the study date, resulting in 38.9% (35,163/90,387) children living in smoking households.Of 90,387 children 44,161 (48,9%) were girls, with 34.6%, 32.2% and 16.8% respectively from White, Asian and Black ethnic groups. Current asthma was recorded in 5.1% (4,633/90,387) of children. After adjustment for child age, sex and ethnic group, children sharing a household with at least one smoker were more likely to have current asthma: aOR [95%CI]: 1.10 [1.02,1.18]. This association did not change after adjusting for household overcrowding: 1.11 [1.03,1.18].Conclusion Our findings suggest that one in three children share a household with at least one adult smoker. Children in smoking households were more likely to have current asthma than those in smoke-free households. Exposure to second-hand smoke in the home is a modifiable risk factor for childhood asthma. Future analyses will examine associations with asthma severity.",
  "authors": [
    {
      "affiliations": [
        "Wolfson Institute of Population Health, Queen Mary University of London, London, UK"
      ],
      "name": "Marta Wilk"
    },
    {
      "affiliations": [
        "Wolfson Institute of Population Health, Queen Mary University of London, London, UK"
      ],
      "name": "John Robson"
    },
    {
      "affiliations": [
        "Wolfson Institute of Population Health, Queen Mary University of London, London, UK"
      ],
      "name": "Kelvin Smith"
    },
    {
      "affiliations": [
        "Wolfson Institute of Population Health, Queen Mary University of London, London, UK"
      ],
      "name": "Shahad Aljifri"
    },
    {
      "affiliations": [
        "Wolfson Institute of Population Health, Queen Mary University of London, London, UK"
      ],
      "name": "Carol Dezateux"
    }
  ],
  "title": "OP41 Associations of household smoking with current childhood asthma: retrospective cohort study using linked primary care and housing records",
  "uid": "d443e40c-4bc5-5659-b0a2-2c0f6f947fb8"
}