Electronic letters to:

Research:
Shawn D. Aaron, MD, Katherine L. Vandemheen, BScN, Louis-Philippe Boulet, MD, R. Andrew McIvor, MD, J. Mark FitzGerald, MD, Paul Hernandez, MD, Catherine Lemiere, MD, Sat Sharma, MD, Stephen K. Field, MD, Gonzalo G. Alvarez, MD, Robert E. Dales, MD, Steve Doucette, MSc, Dean Fergusson, PhD for the Canadian Respiratory Clinical Research Consortium
Overdiagnosis of asthma in obese and nonobese adults
CMAJ 2008; 179: 1121-1131 [Abstract] [Full text] [PDF]
*eLetters: Submit a response to this article

Electronic letters published:

[Read eLetter] Guideline Translation to Improve Diagnostic Accuracy and Health Outcomes
Christopher J Licskai   (23 January 2009)
[Read eLetter] Asthma overdiagnosis, a cognitive error?
Matthew N. Fine   (20 January 2009)
[Read eLetter] Other reasons for asthma overdiagnosis
Jacalyn Duffin   (18 November 2008)

Guideline Translation to Improve Diagnostic Accuracy and Health Outcomes 23 January 2009
Previous eLetter Top
Christopher J Licskai
University of Western Ontario

Send letter to journal:
Re: Guideline Translation to Improve Diagnostic Accuracy and Health Outcomes

clicskai{at}uwo.ca Christopher J Licskai

Christopher J. Licskai MD, University of Western Ontario, London, ON, Canada; M. Diane Lougheed MD, Kingston General Hospital, Queen's University, Kingston, ON, Canada; Teresa To PhD, The Hospital for Sick Children, The University of Toronto, Toronto, ON, Canada; Itamar E. Tamari MD, Stonegate Community Health Centre, Toronto, ON, Canada.

Whereas the Canadian Asthma Consensus Guidelines (CACG) emphasize the use of objective measures for the diagnosis of asthma (1), in the Nov. 18 edition of the CMAJ, Aaron et al reported that 31.8% of adults previously diagnosed with asthma did not meet published diagnostic criteria. The study underscores the challenge of asthma over-diagnosis and potentially unnecessary long-term asthma therapy. It is equally important that spirometry be utilized to evaluate individuals with respiratory symptoms to avoid under-diagnosis and a missed opportunity for effective asthma treatment. The Aaron study highlights the need to address current gaps in the implementation of guideline based care. Two recent Ontario studies (2,3) reported significant improvements in the guideline-based diagnosis and management of asthma in primary care. Both studies evaluated a care model that positioned certified asthma educators as key agents of guideline implementation within a multidisciplinary team. Guideline-based tools were used to prompt accurate diagnosis and evidence based management including spirometry as the primary means of objective diagnosis. This evidence based model is now available in selected sites in Ontario within the Primary Care Asthma Program (PCAP) – Ontario Asthma Plan of Action funded by the Ministry of Health and Long-Term Care and administered in partnership with the Ontario Lung Association (4). The diagnostic errors identified in the Aaron study highlight the challenges of guideline implementation in chronic disease management and the importance of healthcare transformation to care models that facilitate guideline translation such as the PCAP. Such transformational change promises to improve health outcomes for all Canadians.

(1) Boulet LP, Becker A, Bérubé D, Beveridge R, Ernst P on behalf of the Canadian Asthma Consensus Group, Canadian Asthma Consensus Report, 1999, Canadian Medical Association Journal, Volume 161 (Supplement 11), November 30, 1999.

(2) To T, Cicutto L, Degani N, McLimont S, Beyene J, Can a Community Evidence-based Asthma Care Program Improve Clinical Outcomes? A Longitudinal Study, Medical Care, Volume 46, Number 12, December 2008.

(3) Licskai CJ, Ong M, Paolatto L, Nicoletti I, Sands T, Implementing Asthma Guidelines: A Community-Based, Electronically Supported, Interdisciplinary Model for Asthma Management in Canada, Chest, Volume 132 (4 suppl.), October 2007.

(4) Primary Care Asthma Program – Ontario Lung Association. http://www.on.lung.ca/Health-Care-Professionals/PCAP/about-pcap.php

Conflict of Interest:

None declared
Asthma overdiagnosis, a cognitive error? 20 January 2009
Previous eLetter Next eLetter Top
Matthew N. Fine
Oroville Hospital

Send letter to journal:
Re: Asthma overdiagnosis, a cognitive error?

mfine{at}orohosp.com Matthew N. Fine

Editor:

After reading about the overdiagnosis of asthma in the Hospitalist- eWire, I obtained a copy of your article by Aaron, et al, in the November 18th issue of the journal. (1) The finding that asthma is over diagnosed was not unexpected but the 30% rate was surprising.

I believe that this is an example of a cognitive error know as “availability bias”. Availability bias is a faulty heuristic defined as “tendency to judge the likelihood of an event by the ease with which relevant examples comes to mind”.(2) In this case, it is likely that the diagnosis of asthma was applied to relatively young patients who presented with dyspnea. In our hospital, we see the same phenomenon with COPD. In this case, it applies to older patients, usually smokers or with a history of smoking, who also present with dyspnea. Many of these patients never have had a spirometry or have had a spirometry that does not show obstructive airway disease. It results in misdiagnosis and mistreatment.

This cognitive error associated with asthma, COPD and other diagnoses may increase the cost of medical care, increase cost to society and possibly lead to patient harm. Awareness of availability bias can be helpful in avoiding it and may help lead physicians to the articles conclusion that “physicians should consider objective testing” before labeling and treating a patient for diseases or conditions they may not have.

Sincerely,

Matthew N. Fine, MD Director, Medical Services & Patient Safety

1. Aaron S., Vandemheen, K., Boulet, L, et al. Overdiagnosis of asthma in obese and non-obese adults. CMAJ 2008; 1121-1131.

2. Tversky, A., Kahneman, D., Availability: A heuristic for judging frequency and probability. Cognitive Psychology 1973; 207-232.

Conflict of Interest:

None declared
Other reasons for asthma overdiagnosis 18 November 2008
Next eLetter Top
Jacalyn Duffin
Queen's University at Kingston

Send letter to journal:
Re: Other reasons for asthma overdiagnosis

duffinj{at}queensu.ca Jacalyn Duffin

Bravo to Shawn Aaron and his team for their study on asthma overdiagnosis and its intelligent discussion.

They write that one reason for the overdiagnosis "may be a consequence of patients' better education, increased awareness of symptoms and increased readiness to report them to a physician."

We also need to ask to what extent the "education" and "awareness" are produced by pharmaceutical advertising, including the direct-to-consumer variety, which, though still illegal, infiltrates our country via satellite and internet. And is it really "better?"

Conflict of Interest:

None declared