Format

Send to

Choose Destination
J Allergy Clin Immunol. 2014 Nov;134(5):1057-62.e5. doi: 10.1016/j.jaci.2014.05.012. Epub 2014 Jun 27.

Trends in the age of diagnosis of childhood asthma.

Author information

1
Children's Hospital, London Health Sciences Centre, London, Ontario, Canada; Department of Pediatrics, Western University, London, Ontario, Canada; Institute for Clinical Evaluative Sciences, London, Ontario, Canada. Electronic address: dhenuka@gmail.com.
2
Division of Respiratory Medicine, Hospital for Sick Children, Toronto, Ontario, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada; Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada.
3
Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada; Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada; Division of Pediatric Medicine, Hospital for Sick Children, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
4
Institute for Clinical Evaluative Sciences, London, Ontario, Canada.
5
Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada; Child Health Evaluative Sciences, Hospital for Sick Children, Toronto, Ontario, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.

Abstract

BACKGROUND:

The cause of rising asthma incidence over time remains unexplained. Examining trends in the age of diagnosis across successive birth cohorts may offer insights into asthma etiology.

OBJECTIVE:

To examine trends in the age at asthma diagnosis and the age and proportion of children hospitalized at first asthma diagnosis in Ontario, Canada.

METHODS:

Eight consecutive birth cohorts of children (1993-2000) were observed using administrative data from a universal health insurance plan in Ontario, Canada (population 13 million). Trends in the need for hospitalization and age at asthma diagnosis were examined with descriptive and survival analyses.

RESULTS:

The records of 1,059,511 children were examined, of whom 201,958 developed asthma in the first 8 years of life, with an average cumulative incidence of 19.1%. Mean age at asthma diagnosis decreased from 4.7 ± 1.5 years in birth year 1993 to 2.6 ± 2.0 years in birth year 2000 (P < .0001), with a higher adjusted risk of asthma diagnosis (hazard ratio, 6.7; 95% CI, 6.5-6.9) in the first 3 years of life for children born after 1996 versus children born in the period 1993 to 1995 (hazard ratio, 1.4; 95% CI, 1.3-1.4). The proportion of children hospitalized at asthma diagnosis stayed stable while the age at first asthma hospitalization decreased over time (P < .0001).

CONCLUSIONS:

This study demonstrates a significant increase in asthma incidence and a decrease in the age of asthma diagnosis across multiple birth cohorts. Changes in asthma incidence over time are primarily explained by variations in asthma rates in children younger than 3 years.

KEYWORDS:

Asthma; administrative data; child; epidemiology; incidence; prevalence; rate

PMID:
24985402
DOI:
10.1016/j.jaci.2014.05.012
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center