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Faculty Member

Teresa To MSc, Ph.D.

Email Address(es)
Office Phone
(416) 813-8498
Office Address
Child Health Evaluative Sciences, Research Institute The Hospital for Sick Children Toronto, ON M5G 1X8
Biostatistics Division
Epidemiology Division
SGS Status
Full Member
Appointment Status
Status Only

Research Interests

  • Asthma epidemiology and surveillance
  • Paediatric health services and outcomes research
  • Population surveillance
  • Epidemiologic methods

Education & Training History

MSc and Ph.D. – University of Pittsburgh, Graduate School of Public Health, Pittsburgh, Pennsylvania, USA

Other Affiliations

2004-current. Ontario Respiratory Outcomes Network, Co-Chair
2006-current. Chronic Respiratory Disease Surveillance, PHAC Administrative Data Working Group, Member
2006-current. Chronic Respiratory Disease Surveillance Advisory Committee, PHAC, Chair
2010-current. Primary Care Asthma Program Steering Committee, Ontario Lung Association, Member
2011-current. Global Alliance against Chronic Respiratory Diseases (GARD), Member
2012-current. Contributors Oversight Committee, ICES@UofT, Chair
2012-current. Management Committee, ICES@UofT, Member
2013-current. Air Quality Health Index Health Research Working Group, Health Canada, Member

Primary Teaching Responsibilities


Respiratory Global Research And Training (GREAT) Network Epidemiology, Biostatistics and Surveillance Practicum; AllerGen NCE funded program. Offered to International trainees and students at IMS, University of Toronto.


Series in Data Management and Biostatistics, offered by Biostatistics Methodology Unit, Biostatistics Design Analysis Unit, Child Health Evaluative Sciences, The Hospital for Sick Children.


Categorical Data Analysis, Dalla Lana School of Public Health, University of Toronto.

Professional Summary & Appointments

1998-current Institute for Clinical Evaluative Sciences (ICES), Senior Adjunct Scientist

1998-current Institute of Medical Science, cross appointment

1996-current Institute of Health Policy, Management and Evaluation

Honours & Awards

  • Investigator Award, Canadian Institute for Health Research (CIHR) / Ontario Ministry of Health and Long-Term Care (2001-2006)
  • Arnold Naimark Feature Symposium Award, CIHR National Research Forum for Young Investigators in Circulatory and Respiratory Health (2006)
  • Dales Award in Medical Research, University of Toronto, Life Sciences Committee (2008-2011)
  • Eminent Scientist of the Year 2008 International Award in the field of Pediatrics and Community Health Research, World Scientists Forum (2008)
  • Eugenie Stuart Award for Excellence in MSc/PhD Thesis Supervision, Institute of Health Policy, Management and Evaluation, University of Toronto (2012)

Current Research Projects


Ontario Asthma Surveillance Information System (OASIS). Ontario Ministry of Health and Long-Term Care. Asthma Plan of Action. PI: To T.


The Canadian Healthy Infant Longitudinal Development (CHILD) Study. Sears M (PI), To T (Co-I), Scott J, Befus AD, Cherry NM, Becker A.


Correlation of Air Quality Health Index (AQHI) and Chronic Disease Morbidities. Ministry of the Environment (Ontario). Best in Science. PI: To T. Co-I(s): Dell S, Licskai C.


Development of National Strategies for Implementing and Evaluating Evidence-Based Indicators for Benchmarking and Monitoring Asthma Care in Canada. CIHR and AllerGen NCE Inc. Planning Grants. PI: To T.


Validation and use of evidence-based asthma care performance indicators in Ontario (VALUE-API). Ontario Lung Association. National Grant Review/Grant-In-Aid. PI: To T. Co-I(s). Dell S, Gershon A, Lougheed D, Tamari I.


A Feasibility Pilot Study of Ultrasound -Guidance for Difficult Lumbar Punctures in Children with Cancer. Garron Family Cancer Centre Small Grant. PI: Lillian Sung. Co-I(s): Shaikh F, Carvalho J, Arzola C, Alexander S, To T.


Inflammatory Bowel Disease in Immigrants to Canada and their Children. Children’s Hospital Academic Medical Organization (CHAMO). Innovation Grant. PI: Benchimol E. Co-I(s): Guttmann A, Mack D, Manuel D, To T.


AsthmaLife: Integrating Performance Evaluation into the Process of Asthma Care. AHSC AFP Innovation Fund. PI: Diane Lougheed. Co-I(s) Ellis A, Barber D, Hall-Barber K, Flavin M, Birtwhistle R, To T.

Representative Publications

Represented Peer-reviewed Publications in the last 5 years:

To T, Stanojevic S, Feldman R, Moineddin R, Atenafu EG, Guan J, Gershon AS; RESPONSE Team. Is asthma a vanishing disease? A study to forecast the burden of asthma in 2021. BMC Public Health. 2013 Mar 21;13(1):254. [PMID:23517452]

Gershon AS, Guan J, Victor JC, Goldstein R, To T. Quantifying health services use for chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 2013 Mar 15;187(6):596-601. [PMID:23328526]

Crighton EJ, Feng J, Gershon A, Guan J, To T. A spatial analysis of asthma prevalence in Ontario. Can J Public Health. 2012;103(5):384-89

To T, Shen S, Atenafu EG, Guan J, McLimont S, Stocks B, Licskai C. The Air Quality Health Index and asthma morbidity: A population-based study. Environ Health Perspect. 2012 Oct 10. [Epub ahead of print] [PMID 23060364]

Gershon AS, Victor JC, Guan J, Aaron SD, To T. Pulmonary function testing in the diagnosis of asthma: a population study. Chest. 2012 May;141(5):1190-6. Epub 2011 Oct 26. [PMID 22030804]

To T, Daly C, Feldman R, McLimont S. Results from a community-based program evaluating the effect of changing smoking status on asthma symptom control. BMC Public Health. 2012 Apr 20;12 Art No 293: [9 p.]. [PMID 22520046]

To T, Stanojevic S, Moores G, Gershon AS, Bateman ED, Cruz AA, Boulet LP. Global asthma prevalence in adults: findings from the cross-sectional world health survey. BMC Public Health. 2012 Mar 19;12 Art No 204:[8 p.]. [PMID 22429515]

To T, Guan J, Wang C, Radhakrishnan D, McLimont S, Latycheva O, Gershon AS. Is large birth weight associated with asthma risk in early childhood? Arch Dis Child. 2012 Feb;97(2):169-71. Epub 2010 Sep 23. [PMID 20870629]

Gershon AS, Guan J, Wang C, Victor JC, To T. Describing and quantifying asthma comorbidity: a population study. PLoS One. 2012;7(5):e34967. Epub 2012 May 7. [PMID 22586445]

To T, McLimont S, Daly C, Moores G, Gershon AS, Lougheed MD. Is it feasible to use indicators to collect data on asthma care performance in the primary care setting? A feasibility study. [letter]. Prim Care Respir J. 2011 Dec;20(4):452-3. Epub 2011 Sep 21. [PMID 21938351]

To T, Tarlo SM, McLimont S, Haines T, Holness DL, Lougheed MD, Liss GM, Cicutto L. Feasibility of a provincial voluntary reporting system for work-related asthma in Ontario. Can Respir J. 2011 Sep-Oct;18(5):275-7. [PMID 21969929]

Gershon AS, Warner L, Cascagnette P, Victor JC, To T. Lifetime risk of developing chronic obstructive pulmonary disease: a longitudinal population study. Lancet. 2011 Sep 10;378(9795):991-6. [PMID 21907862]

To T, Guttmann A, Lougheed MD, Gershon AS, Dell SD, Stanbrook MB, Wang C, McLimont S, Vasilevska-Ristovska J, Crighton EJ, Fisman DN. Evidence-based performance indicators of primary care for asthma: a modified RAND Appropriateness Method. Int J Qual Health Care. 2010 Dec;22(6):476-85. Epub 2010 Oct 25. [PMID 20978002]

Gershon AS, Guan J, Wang C, To T. Trends in asthma prevalence and incidence in Ontario, Canada, 1996 to 2005: a population study. Am J Epidemiol. 2010 Sep 15;172(6):728-36. Epub 2010 Aug 17. [PMID 20716702]

To T, Wang C, Dell SD, Fleming-Carroll B, Parkin P, Scolnik D, Ungar WJ; PAMG Team. Can an evidence-based guideline reminder card improve asthma management in the emergency department? Respir Med. 2010 Sep;104(9):1263-70. [PMID 20434896]

To T, Langer JC. Does access to care affect outcomes of appendicitis in children? – a population-based cohort study. BMC Health Serv Res. 2010 Aug 25;10 Art No 250:[7 p.]. [PMID 20735857]

Gershon AS, Wang C, Wilton AS, Raut R, To T. Trends in population burden of COPD: actual facts or fallacies?–Reply. Arch Intern Med. 2010 Aug 9/23;170(15):1409-10. [PMID 20308643]

Gershon AS, Wang C, Guan J, To T. Burden of comorbidity in individuals with asthma. Thorax. 2010 Jul;65(7):612-8. [PMID 20627918]

Charach A (P), Schachar R, Lin E, To T. Evaluating the hyperactivity/inattention sub-scale of the National Longitudinal Survey of Children and Youth (NLSCY). Health Rep. 2010 Jun;21(2):e1-8. [PMID 20632524]

Gershon AS, Wang C, Wilton AS, Raut R, To T. Trends in chronic obstructive pulmonary disease prevalence, incidence, and mortality in Ontario, Canada, 1996 to 2007: a population-based study. Arch Intern Med. 2010 Mar 22;170(6):560-5. [PMID 20308643]

To T, Wang C, Guan J, McLimont S, Gershon AS. What is the lifetime risk of physician diagnosed asthma in Ontario, Canada? Am J Respir Crit Care Med. 2010 Feb 15;181(4):337-43. Epub 2009 Nov 19. [PMID 19926867]

Gershon AS, Wang C, Guan J, Vasilevska-Ristovska J, Cicutto L, To T. Identifying patients with physician diagnosed asthma in health administrative databases. Can Respir J. 2009 Nov-Dec;16(6):183-8. [PMID 20011725]

Gershon AS, Wang C, Guan J, Vasilevska-Ristovska J, Cicutto L, To T. Identifying individuals with physician diagnosed COPD in health administrative databases. COPD. 2009 Oct;6(5):388-94. [PMID 19863368]

To T, McLimont S, Wang C, Cicutto L. How much do health care providers value a community-based asthma care program? – a survey to collect their opinions on the utilities of and barriers to its uptake. BMC Health Serv Res. 2009 May 11;9 Art No 77:[8 p.]. [PMID 19432986]

To T, Dell S, Tassoudji M, Wang C. Health outcomes in low-income children with current asthma in Canada. Chronic Dis Can. 2009;29(2):49-55. [PMID 19281690]

To T, Cicutto L, Degani N, McLimont S, Beyene J. Can a community evidence-based asthma care program improve clinical outcomes? A longitudinal study. Med Care. 2008 Dec;46(12):1257-66. [PMID 19300316]

To T, Estrabillo E, Wang C, Cicutto L. Examining intra-rater and inter-rater response agreement: a medical chart abstraction study of a community-based asthma care program. BMC Med Res Methodology. 2008 May 9;8 Art No 29:[9 p.]. [PMID 18471298]