Browsing by Author "Rutter CE"

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    Are Environmental Factors for Atopic Eczema in ISAAC Phase Three due to Reverse Causation?
    (Elsevier, Inc. on behalf of the Society for Investigative Dermatology, 2019-05) Rutter CE; Silverwood RJ; Williams HC; Ellwood P; Asher I; Garcia-Marcos L; Strachan DP; Pearce N; Langan SM; ISAAC Phase Three Study Group
    Some previously described environmental associations for atopic eczema may be due to reverse causation. We explored the role of reverse causation by comparing individual- and school-level results for multiple atopic eczema risk factors. The International Study of Asthma and Allergies in Childhood (i.e, ISAAC) Phase Three surveyed children in schools (the sampling unit) regarding atopic eczema symptoms and potential risk factors. We assessed the effect of these risk factors on atopic eczema symptoms using mixed-effect logistic regression models, first with individual-level exposure data and second with school-level exposure prevalence. Overall, 546,348 children from 53 countries were included. At ages 6-7 years, the strongest individual-level associations were with current paracetamol use (odds ratio [OR] = 1.45, 95% confidence interval [CI] = 1.37-1.54), which persisted at school-level (OR = 1.55, 95% CI = 1.10-2.21), early-life antibiotics (OR = 1.41, 95% CI = 1.34-1.48), and early-life paracetamol use (OR = 1.28, 95% CI = 1.21-1.36), with the former persisting at the school level, whereas the latter was no longer observed (OR = 1.35, 95% CI = 1.00-1.82 and OR = 0.94, 95% CI = 0.69-1.28, respectively). At ages 13-14 years, the strongest associations at the individual level were with current paracetamol use (OR = 1.57, 95% CI = 1.51-1.63) and open-fire cooking (OR = 1.46, 95% CI = 1.33-1.62); both were stronger at the school level (OR = 2.57, 95% CI = 1.84-3.59 and OR = 2.38, 95% CI = 1.52-3.73, respectively). Association with exposure to heavy traffic (OR = 1.31, 95% CI = 1.27-1.36) also persisted at the school level (OR = 1.40, 95% CI = 1.07-1.82). Most individual- and school-level effects were consistent, tending to exclude reverse causation.
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    Asthma inflammatory phenotypes on four continents: most asthma is non-eosinophilic
    (Oxford University Press on behalf of the International Epidemiological Association, 2023-04) Pembrey L; Brooks C; Mpairwe H; Figueiredo CA; Oviedo AY; Chico M; Ali H; Nambuya I; Tumwesige P; Robertson S; Rutter CE; van Veldhoven K; Ring S; Barreto ML; Cooper PJ; Henderson J; Cruz AA; Douwes J; Pearce N; WASP Study Group
    BACKGROUND: Most studies assessing pathophysiological heterogeneity in asthma have been conducted in high-income countries (HICs), with little known about the prevalence and characteristics of different asthma inflammatory phenotypes in low-and middle-income countries (LMICs). This study assessed sputum inflammatory phenotypes in five centres, in Brazil, Ecuador, Uganda, New Zealand (NZ) and the United Kingdom (UK). METHODS: We conducted a cross-sectional study of 998 asthmatics and 356 non-asthmatics in 2016-20. All centres studied children and adolescents (age range 8-20 years), except the UK centre which involved 26-27 year-olds. Information was collected using questionnaires, clinical characterization, blood and induced sputum. RESULTS: Of 623 asthmatics with sputum results, 39% (243) were classified as eosinophilic or mixed granulocytic, i.e. eosinophilic asthma (EA). Adjusted for age and sex, with NZ as baseline, the UK showed similar odds of EA (odds ratio 1.04, 95% confidence interval 0.37-2.94) with lower odds in the LMICs: Brazil (0.73, 0.42-1.27), Ecuador (0.40, 0.24-0.66) and Uganda (0.62, 0.37-1.04). Despite the low prevalence of neutrophilic asthma in most centres, sputum neutrophilia was increased in asthmatics and non-asthmatics in Uganda. CONCLUSIONS: This is the first time that sputum induction has been used to compare asthma inflammatory phenotypes in HICs and LMICs. Most cases were non-eosinophilic, including in settings where corticosteroid use was low. A lower prevalence of EA was observed in the LMICs than in the HICs. This has major implications for asthma prevention and management, and suggests that novel prevention strategies and therapies specifically targeting non-eosinophilic asthma are required globally.