Dr. Malcolm Sears

Division of Respirology

Malcolm Sears


Professor Emeritus, Division of Respirology, Department of Medicine

St. Joseph's Healthcare





Education and Professional Standing

Dr. Malcolm Sears graduated from the University of Otago, Dunedin, New Zealand and was on faculty there until 1990 when he was recruited as the Director of the Firestone Regional Chest and Allergy Unit (the forerunner of the Firestone Institute of Respiratory Health), Director of Respiratory Medicine at St. Joseph’s Healthcare and Professor in the Department of Medicine at McMaster University. In 2002 he stepped down as Clinical Director and became Research Director of the Firestone Institute until 2009.

Awards and Distinctions

Who's Who (New Zealand) (1993-)
Who's Who (Canada) (1993-)
Who's Who (Ontario) (1994-)
International Who's Who in Medicine (1994-)
Wunderly Orator, Thoracic Society Australia and New Zealand (1997)
Christie Memorial Lecturer, Canadian Thoracic Society (2011)
Award for Leadership in Health Research, Asthma Society of Canada (2015)

Research Interests

Dr. Sears is involved in many studies investigating the epidemiology and natural history of asthma with particular focus on its frequency, risk factors and characteristics in large populations. Of note is an important longitudinal study that he has been conducting for more than 30 years, studying the incidence and impact of asthma in a birth cohort of New Zealand children followed from infancy to adulthood. Other research includes assessment of asthma therapies, and the effects of indoor allergens, viral infections, air pollutants, smoking and hormones in respiratory disease. He is director of the CIHR/AllerGen funded Canadian Healthy Infant Longitudinal Development (CHILD) Study following over 3000 infants from pregnancy to age 5 years.

Dr. Sears has published over 250 peer-reviewed papers and book chapters, together with numerous abstracts. He lectures frequently at national and international scientific meetings, and serves on many asthma advisory boards.

Dr. Sears holds an endowed Astra Zeneca Chair in Respiratory Epidemiology at McMaster University.


Health Research Council of New Zealand
Longitudinal study of natural history of asthma

Indoor air exposures, genes and gene-environment interactions in the etiology of asthma and allergy in early childhood
Viral infection and wheezing in the first year of life
Program grant in Food and Health: Understanding the impact of maternal and infant nutrition on infant/child health
Lung function in preschool children: utility in diagnosis of asthma
Early Life Determinants of Asthma

AllerGen NCE
Planning a Canadian longitudinal birth cohort study of asthma and allergy in childhood
Indoor air exposures, genes and gene-environment interactions in the etiology of asthma and allergy in early childhood

Merck-Frosst Canada
Seasonal epidemics of asthma admissions
Seasonal intervention with montelukast

Childhood Asthma Foundation
Canadian Healthy Infant Longitudinal Development study

Canadian Mortgage and Housing Company
Environmental assessment of CHILD homes

Selected Publications

  1. Long-term relation between breastfeeding and development of atopy and asthma in children and young adults: a longitudinal study. Lancet 2002; 360:901-7.
  2. Risk factors for airway remodeling in asthma manifested by a low post-bronchodilator FEV1/vital capacity ratio: a longitudinal population study from childhood to adulthood. Am J Respir Crit Care Med 2002;165:1480-1488.
  3. A longitudinal population-based cohort study of childhood asthma followed to adulthood. N Engl J Med. 2003;349:1414-22
  4. The September epidemic of asthma hospitalization: school children as disease vectors. J AllergyClinImmunol 2006;117:557-562.
  5. Interactions between breast-feeding, specific parental atopy, and sex on development of asthma and atopy. J Allergy ClinImmunol2007; 119:1359-66
  6. Understanding the September asthma epidemic.  J Allergy ClinImmunol 2007;120:526-529
  7. Epidemiology of asthma exacerbations.  J Allergy ClinImmunol 2008:122:662-8
  8. Epidemiology of asthma: risk factors for development. Expert Review ClinImmunol 2009;5:77-95.
  9. Asthma: epidemiology, etiology and risk factors.  CMAJ 2009;181:E181-190
  10. Effects of cannabis on lung function: a population-based cohort study.  EurRespir J 2010; 35 42-47
  11. Exposure assessment in cohort studies of childhood asthma.  Environ Health Perspect. 2011;119:591-597.
  12. A gradient of childhood self-control predicts health, wealth, and public safety. PNAS 2011;108:2693-2698.
  13. Relevance of birth cohorts to assessment of asthma persistence. Curr Allergy Asthma Rep 2012;12:175-184
  14. The FDA-mandated trial of safety of long-acting beta-agonists in asthma: Finality or futility?  Thorax 2013;68:195-198.
  15. Polygenic risk and the development and course of asthma: an analysis of data from a four-decade longitudinal study. Lancet Respiratory Medicine 2013;1:453-461.
  16. The potential to predict the course of childhood asthma. Expert Rev Respir Med. 2014;8:137-141.
  17. The Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort study: assessment of environmental exposures. J Expo Sci Environ Epidemiol 2015 (epub).
  18. The Canadian Healthy Infant Longitudinal Development birth cohort study: biological samples and biobanking. Paediatr and Perinat Epidemiol 2015;29:84-92.
  19. The Canadian Healthy Infant Longitudinal Development (CHILD) Study: examining developmental origins of allergy and asthma. Thorax 2015;70:998-1000.
  20. Early life microbial and metabolic alterations affect risk of childhood asthma.  SciTransl Med 2015;7:307ra152.