Abstract
Introduction Early disease morbidity has been associated with asthma persistence in wheezing preschoolers; however, whether asthma control trajectories shortly after diagnosis could influence remission is unknown. We examined the association between asthma control trajectories 2 years post-diagnosis in preschoolers and subsequent disease remission.
Methods We conducted a multicentre population-based retrospective cohort study consisting of 48 687 children with asthma diagnosed before 5 years old and born between 1990 and 2013 in four Canadian provinces who had prolonged disease activity post-diagnosis. Prolonged disease activity was defined as one or more medical visits or medications for asthma every 6-month period for at least four of the six periods post-diagnosis. Follow-up began at 3 years post-diagnosis (at cohort entry). Remission was defined as 2 consecutive years without drug claims or medical visits for asthma or asthma-like conditions following cohort entry. Asthma control trajectories, ascertained over four 6-month periods following diagnosis using a validated index, were classified as: “controlled throughout”, “improving control”, “worsening control”, “out of control throughout” and “fluctuating control”. Adjusted Cox models estimated associations between asthma control trajectories and time to remission. A random effects meta-analysis summarised province-specific hazard ratios (HRs).
Results The pooled remission rate was 8.91 (95% CI 8.80–9.02) per 100 person-years. Compared with children controlled throughout, poorer asthma control was associated with incrementally lower hazard ratios of remission in four other trajectories: improving control (HR 0.89, 95% CI 0.82–0.96), fluctuating control (HR 0.78, 95% CI 0.71–0.85), worsening control (HR 0.68, 95% CI 0.62–0.75) and out of control throughout (HR 0.52, 95% CI 0.45–0.59).
Conclusions Asthma control trajectories 2 years following a diagnosis in preschoolers were associated with remission, highlighting the clinical relevance of documenting control trajectories in early life.
Abstract
In this multicentre population-based cohort study, the worse the asthma control trajectory shortly following diagnosis in preschoolers, the lower the likelihood of remission https://bit.ly/3lHVsNf
Footnotes
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Author contributions: F.M. Ducharme and C. Longo had full access to the Quebec data, M. Brownell had full access to the Manitoba data, J.M. Quail had full access to the Saskatchewan data, and M. Sadatsafavi had full access to the British Columbia data; these authors take joint responsibility for the integrity of the data and the accuracy of the data analysis. C. Longo, L. Blais, M. Brownell, J.M. Quail, M. Sadatsafavi, R.W. Platt and F.M. Ducharme contributed to the conception of the research question and the design. C. Longo, L. Blais, M. Brownell, J.M. Quail, M. Sadatsafavi, R.W. Platt, F.M. Ducharme, A. Forget, M-A. Turcot, Y. Nie, W. Li, H. Tavakoli, Q. Tan and Y. Fan acquired, analysed or interpreted the data. C. Longo and F.M. Ducharme drafted the manuscript, and all authors critically revised and approved the manuscript.
Conflict of interest: C. Longo has nothing to disclose.
Conflict of interest: L. Blais reports grants, personal fees and research contracts from AstraZeneca, grants from Teva, outside the submitted work.
Conflict of interest: M. Brownell has nothing to disclose.
Conflict of interest: J.M. Quail has nothing to disclose.
Conflict of interest: M. Sadatsafavi has nothing to disclose.
Conflict of interest: A. Forget has nothing to disclose.
Conflict of interest: M-A. Turcot has nothing to disclose.
Conflict of interest: Y. Nie has nothing to disclose.
Conflict of interest: W. Li has nothing to disclose.
Conflict of interest: H. Tavakoli has nothing to disclose.
Conflict of interest: Q. Tan has nothing to disclose.
Conflict of interest: Y. Fan has nothing to disclose.
Conflict of interest: R.W. Platt reports personal fees from Biogen, Amgen, Merck, AbbVie, Pfizer, Elli Lilly and Analysis Group, outside the submitted work.
Conflict of interest: F.M. Ducharme reports grants from GlaxoSmithKline Canada and MedTeq, grants and personal fees for lectures from Covis Pharma and Thorasys Inc., unrestricted donations from Novartis and Trudell Medical International, outside the submitted work.
Support statement: This study was funded by the Canadian Respiratory Research Network (CRRN). The CRRN is supported by grants from the Canadian Institutes of Health Research (CIHR)–Institute of Circulatory and Respiratory Health (132213), Canadian Lung Association (CLA)/Canadian Thoracic Society (CTS), British Columbia Lung Association, and Industry Partners Boehringer Ingelheim Canada Ltd, AstraZeneca Canada Inc. and Novartis Canada Ltd. We also acknowledge the Fonds de Recherche du Québec–Santé for the fellowship award to C. Longo, and the infrastructure support provided to the Research Centre of the CHU Sainte-Justine, Hôpital du Sacré-Cœur de Montréal, McGill University Health Centre and the Lady Davis Institute of the Jewish General Hospital in Montreal. The funders had no role in the study design, data collection and analysis or preparation of the manuscript. Funding information for this article has been deposited with the Crossref Funder Registry.
- Received May 20, 2020.
- Accepted November 11, 2020.
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