bronchial challenge testing into a caseﬁnding strategy
identiﬁed asthma in 26% of symptomatic individuals
who had normal spirometry and no response to BD.27
Individuals with undiagnosed respiratory symptoms,
determined to have asthma or COPD through
spirometry, experience poor health status.28 Therefore,
the implementation of known treatment approaches for
asthma or COPD is important to improve their
conditions.29 In contrast, those with normal spirometry
or PRISm face unclear treatment approaches. Long-
acting BD therapy in symptomatic individuals with
tobacco exposure with normal spirometry is not
effective.30 Weight management programs may be useful
for individuals who are obese with PRISm-related
dyspnea; however, this awaits deﬁnitive clinical trials.31
Dyspnea was severe and prevalent within our study
group; however, it remained undiagnosed. A study
conducted by Stefan et al32 revealed that physicians
underestimated their patients’ dyspnea 37.9% of the
time, whereas nurses underestimated it 3.5% of the time.
Moreover, many patients limit their physical activities,
which lead them to downplay the extent of their
dyspnea.19 Patient underreporting of symptoms, coupled
with inadequate physician-led investigations of
symptoms, may explain why dyspnea often goes
undiagnosed in the population.33
In conclusion, our study measured dyspnea impact in
individuals with no preexisting diagnosis of lung disease
who reported respiratory symptoms as part of a
purposeful caseﬁnding strategy. Individuals with PRISm
exhibited the greatest impact of dyspnea, even higher
than those newly diagnosed with asthma or COPD.
After adjusting for patient factors, comorbidities,
pulmonary diseases, and severity of lung physiologic
impairment, most of the variability in dyspnea remained
unexplained. We also showed that dyspnea was
associated with increased health care utilization,
impaired quality of life, and work productivity.
Funding/Support
This study is supported by the Canadian Institutes of
Health Research [FDN Grant 154322].
Financial/Nonﬁnancial Disclosures
None declared.
Acknowledgments
Author contributions:S. D. A. and G. A. W.
contributed to conception and design. J. B., E.
G., G. A. W., K. L. V., and S. D. A.
contributed to analysis and interpretation. J.
B., E. G., G. A. W., K. L. V., S. D. A., C. B., C.
L., L.-P. B., A. C., E. P., S. K. F., S. G., R. A.
M., I. M., M. B., P. H., M. D. L., M. A., C. J. L.,
T. A., N. E., G. G. A., and S. M. contributed to
drafting the manuscript for important
intellectual content. All authors had access to
and participated in the interpretation of the
data and provided input into the preparation
and submission of the manuscript. The
authors vouch for the accuracy and
completeness of the data.
Role of sponsors:The sponsor had no role in
the design of the study, the collection and
analysis of the data, or the preparation of the
manuscript.
Other contributions: We thank the
following individuals from the Canadian
study sites: Ottawa Hospital Research
Institute, Ottawa, Ontario: Taylor Poulin;
Susan Deveau, RRT; Victoria Thompson;
Meredith McCleery; Angelina Tohme; Vicky
Panteleakos, RRT; Geneviève Longtin, RRT;
Joanne Cassidy, RRT; Amanda Bergeron,
MSc; Jennifer Biggs, RN; Jessica Bergeron;
and Elisabet White; Vancouver General
Hospital, Vancouver, British Columbia:
Shelley Abercromby, BSc; Jana Caine; David
Savage; Natasha Verzosa; Ravneet Mahal; and
Mary Justine Angeles; Queen Elizabeth II
Health Sciences Centre, Halifax, NS: Scott
Fulton, RRT; Hôpital du Sacré Coeur de
Montréal, Montréal, QC: Simone Chaboillez,
MT; and Meliza Benabdallah; St. Joseph’s
Hamilton, Hamilton, ON: Liz Johnson; St.
Boniface Hospital, Winnipeg, MB: Cheryl
Noble, RN; Institut Universitaire de
Cardiologie et de Pneumologie de Québec-
Université Laval, Québec, QC: Johane
Lepage, BSc; Joanne Milot, RN; and
Christiane Balizet, RN; University of Calgary,
Calgary, AB: Lisette Machado, MD; and
Curtis Dumonceaux, BSc; University of