Comparison of Asthma Control Criteria: Importance of Spirometry

Abstract

Aims. To compare the measurements of asthma control using Canadian Thoracic Society (CTS) Asthma Management Consensus Summary and Global Initiative for Asthma (GINA) guidelines composite indices with and without spirometry. Methods. Asthma control parameters were extracted from electronic medical records (EMRs) of patients ≥6 years old at two primary care sites. Asthma control ratings calculated according to CTS and GINA criteria were compared. Results. Data were available from 113 visits by 93 patients, aged 6–85 years (38.7 ± 24.8; mean ± SD). The proportion of visits at which individuals’ asthma was completely controlled was 22.1% for CTS symptoms only and 9.7% for CTS with spirometry (p < .01); and 17.7% versus 14.1% for GINA symptoms only versus symptoms with spirometry (p = .125). Conclusions. Asthma control ratings using GINA and CTS criteria are discordant in more than half of the patients deemed “in control” by at least one scale. Differences in the spirometry criterion threshold are primarily responsible for this discordance. Failure to include spirometry as part of the control index consistently overestimates asthma control and may underestimate future risk of exacerbations.

• asthma control
• electronic medical records
• guidelines
• primary care
• spirometry

Acknowledgments

We thank Nicola Thomas, RN, CAE, and Madonna Ferrone, RRT, CRE, for data collection; the patients and staff of the Kingston PCAP sites (Queen’s Family Health Team, Sharbot Lake Medical Centre, Sydenham Family Health Team, Newburgh Family Health Team, Picton Family Health Team) and patients and staff from more than 12 sites in Windsor-Essex involved in the study, including HDGH Asthma Orphan Clinic, Demarco Group, Harrow Family Health Team, Lasalle Family Health Group, Tecumseh Medical, Leamington Family Health Team, University of Windsor Health Services, and primary care offices of Dr. Al-Tatari and Dr. Maraj for their participation; as well as Blaine Jenkins, Cissec Corporation, and Jason West, University of Windsor Centre for Smart Community Innovation, for their computer programming and support.

Declaration of Interest

M.D. Lougheed has received grant monies from the Government of Ontario, AllerGen Network for Centres of Excellence Inc., Ontario Thoracic Society, Ontario Lung Association, Canadian Institutes for Health Research, Queen’s University, Ception, Topigen, and GlaxoSmithKlein. MDL has received honoraria from the Ontario Lung Association for continuing education program development and presentations. MDL is chair of the Canadian Thoracic Society Asthma Assembly.

T.W. Sands has received grant monies from the Ontario Ministries of Enterprise, Opportunity and Innovation, Economic Development Tourism and Trade, Small Business and Entrepreneurship, Citizenship and Immigration, the Ministry of Government Services, Industry Canada’s Canadian Network for the Advancement of Research Industry and Education, the Essex Community Futures Development Corporation, as well as the Canadian Foundation for Innovation, the Optical Regional Advanced Network of Ontario, Erie-St. Clair Local Health Integration Network, and for academic program development from the Ontario University College Consortium Council. TWS has received honoraria for speaking engagements from a number of the ministries listed above, as well as from Telus Communications Inc. and IBM Canada.

C.J. Licskai has received research support from the Government of Ontario, Ontario Thoracic Society, Ontario Lung Association, and Health Canada. CJL has received honoraria for speaking engagements and/or participated on advisory boards for GlaxoSmithKline, AstraZeneca, Novartis, and Merck. CJL has received honoraria from the Ontario Lung Association for continuing education program development and presentations. CJL is a member of the Canadian Thoracic Society Asthma Assembly and vice-chair of the Canadian Thoracic Society – Canadian Respiratory Guidelines Committee.

This study was funded by the Government of Ontario.