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Background: Exertional breathlessness is a cardinal symptom of cardiorespiratory disease., Research Question: How does breathlessness abnormality, graded using normative reference equations during cardiopulmonary exercise testing (CPET), relate to self-reported and physiologic responses in people with chronic airflow limitation (CAL)?, Study Design and Methods: An analysis was done of people aged ≥ 40 years with CAL undergoing CPET in the Canadian Cohort Obstructive Lung Disease study. Breathlessness intensity ratings (Borg CR10 scale [0-10 category-ratio scale for breathlessness intensity rating]) were evaluated in relation to power output, rate of oxygen uptake, and minute ventilation at peak exercise, using normative reference equations as follows: (1) probability of breathlessness normality (probability of having an equal or greater Borg CR10 rating among healthy people; lower probability reflecting more severe breathlessness) and (2) presence of abnormal breathlessness (rating above the upper limit of normal). Associations with relevant participant-reported and physiologic outcomes were evaluated., Results: We included 330 participants (44% women): mean ± SD age, 64 ± 10 years (range, 40-89 years); FEV 1 /FVC, 57.3% ± 8.2%; FEV 1 , 75.6% ± 17.9% predicted. Abnormally low exercise capacity (peak rate of oxygen uptake < lower limit of normal) was present in 26%. Relative to peak power output, rate of oxygen uptake, and minute ventilation, abnormally high breathlessness was present in 26%, 25%, and 18% of participants. For all equations, abnormally high exertional breathlessness was associated with worse lung function, exercise capacity, self-reported symptom burden, physical activity, and health-related quality of life; and greater physiologic abnormalities during CPET., Interpretation: Abnormal breathlessness graded using CPET normative reference equations was associated with worse clinical, physiological, and functional outcomes in people with CAL, supporting construct validity of abnormal exertional breathlessness., Competing Interests: Financial/Nonfinancial Disclosures The authors have reported to CHEST the following: J. B. and W. C. T. report receiving institutional funding for the CanCOLD study from AstraZeneca Canada Ltd., Boehringer Ingelheim Canada Ltd., GlaxoSmithKline Canada Ltd., Merck, Novartis Pharma Canada Inc., as well as Nycomed Canada Inc. (W. C. T.), Pfizer Canada Ltd. (W. C. T.), Trudell (J. B.), and Grifolds (J. B.). None declared (P. Z. L., M. E., H. L., D. J.)., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Context: The Dyspnoea-12 (D-12) and Multidimensional Dyspnea Profile (MDP) were specifically developed for assessment of multiple sensations of breathlessness., Objectives: This systematic review aimed to identify the use and measurement properties of the D-12 and MDP across populations, settings and languages., Methods: Electronic databases were searched for primary studies (2008-2020) reporting use of the D-12 or MDP in adults. Two independent reviewers completed screening and data extraction. Study and participant characteristics, instrument use, reported scores and minimal clinical important differences (MCID) were evaluated. Data on internal consistency (Cronbach's α) and test-retest reliability (intraclass correlation coefficient, ICC) were pooled using random effects models between settings and languages., Results: A total 75 publications reported use of D-12 (n = 35), MDP (n = 37) or both (n = 3), reflecting 16 chronic conditions. Synthesis confirmed two factor structure, internal consistency (Cronbach's α mean, 95% CI: D-12 Total = 0.93, 0.91-0.94; MDP Immediate Perception [IP] = 0.88, 0.85-0.90; MDP Emotional Response [ER] = 0.86, 0.82-0.89) and 14 day test-rest reliability (ICC: D-12 Total = 0.91, 0.88-0.94; MDP IP = 0.85, 0.70-0.93; MDP ER = 0.84, 0.73-0.90) across settings and languages. MCID estimates for clinical interventions ranged between -3 and -6 points (D-12 Total) with small variability in scores over 2 weeks (D-12 Total 2.8 (95% CI: 2.0 to 3.7), MDP-A1 0.8 (0.6 to 1.1) and six months (D-12 Total 2.9 (2.0 to 3.7), MDP-A1 0.8 (0.6 to 1.1))., Conclusion: D-12 and MDP are widely used, reliable, valid and responsive across various chronic conditions, settings and languages, and could be considered standard instruments for measuring dimensions of breathlessness in international trials., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Physiologic and symptom responses at the ventilatory threshold (Tvent) during incremental cardiopulmonary exercise testing (CPET) can provide important prognostic information., Research Question: This study aimed to develop an updated normative reference set for physiologic and symptom responses at Tvent during cycle CPET (primary aim) and to evaluate previously recommended reference equations from a 1985 study for predicting Tvent responses (secondary aim)., Study Design and Methods: Participants were adults 40 to 80 years of age who were free of clinically relevant disease from the Canadian Cohort Obstructive Lung Disease. Rate of oxygen consumption (V˙O 2 ) at Tvent was identified by two independent raters; physiologic and symptom responses corresponding to V˙O 2 at Tvent were identified by linear interpolation. Reference ranges (5th-95th percentiles) for responses at Tvent were calculated according to participant sex and age for 29 and eight variables, respectively. Prediction models were developed for nine variables (oxygen pulse, V˙O 2 , rate of CO 2 production, minute ventilation, tidal volume, inspiratory capacity, end-inspiratory lung volume [in liters and as percentage of total lung capacity], and end-expiratory lung volume) using quantile regression, estimating the 5th (lower limit of normal), 50th (normal), and 95th (upper limit of normal) percentiles based on readily available participant characteristics. The two one-sided test of equivalence for paired samples evaluated the measured and 1985-predicted V˙O 2 at Tvent for equivalence., Results: Reference ranges and equations were developed based on 96 participants (49% men) with a mean ± SD age of 63 ± 9 years. Mean V˙O 2 at Tvent was 50% of measured V˙O 2 peak; the normal range was 33% to 66%. The 1985 reference equations overpredicted V˙O 2 at Tvent: mean difference in men, -0.17 L/min (95% CI, -0.25 to -0.09 L/min); mean difference in women, -0.19 L/min (95% CI, -0.27 to -0.12 L/min)., Interpretation: A contemporary reference set of CPET responses at Tvent from Canadian adults 40 to 80 years of age is presented that differs from the previously recommended and often used reference set from 1985., Trial Registry: ClinicalTrials.gov; No.: NCT00920348; URL: www.clinicaltrials.gov., (Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Background: Up-to-date normative reference sets for cardiopulmonary exercise testing (CPET) are important to aid in the accurate interpretation of CPET in clinical or research settings., Research Question: This study aimed to (1) develop and externally validate a contemporary reference set for peak CPET responses in Canadian adults identified with population-based sampling; and (2) evaluate previously recommended reference equations for predicting peak CPET responses., Study Design and Methods: Participants were healthy adults who were ≥40 years old from the Canadian Cohort Obstructive Lung Disease who completed an incremental cycle CPET. Prediction models for peak CPET responses were estimated from readily available participant characteristics (age, sex, height, body mass) with the use of quantile regression. External validation was performed with a second convenience sample of healthy adults. Peak CPET parameters that were measured and predicted in the validation cohort were assessed for equivalence (two one-sided tests of equivalence for paired-samples and level of agreement (Bland-Altman analyses). Two one-sided tests of equivalence for paired samples assessed differences between responses in the derivation cohort using previously recommended reference equations., Results: Normative reference ranges (5th-95th percentiles) for 28 peak CPET parameters and prediction models for 8 peak CPET parameters were based on 173 participants (47% male) who were 64 ± 10 years old. In the validation cohort (n = 84), peak CPET responses that were predicted with the newly generated models were equivalent to the measured values. Peak cardiac parameters predicted by the previously recommended reference equations by Jones and colleagues and Hansen and colleagues were significantly higher., Interpretation: This study provides reference ranges and prediction models for peak cardiac, ventilatory, operating lung volume, gas exchange, and symptom responses to incremental CPET and presents the most comprehensive reference set to date in Canadian adults who were ≥40 years old to be identified with population-based sampling., (Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Context: Explanations provided by health professionals may underpin helpful or harmful symptom beliefs and expectations of people living with chronic breathlessness., Objectives: This study sought perspectives from health professionals with clinical/research expertise in chronic breathlessness on priority issues in chronic breathlessness explanations and research., Methods: Authors (n = 74) of publications specific to chronic breathlessness were invited to a three-round Delphi survey. Responses to open-ended questions (Round 1 "What is important to: include/avoid when explaining chronic breathlessness; prioritize in research?") were transformed to Likert scale (1-9) items for rating in subsequent rounds. A priori consensus was defined as ≥70% of respondents rating an item as important (Likert rating 7-9) and interquartile range ≤2., Results: Of the 31 Round 1 respondents (nine countries, five professional disciplines), 24 (77%) completed Rounds 2 and 3. Sixty-three items met consensus (include n = 28; avoid n = 9; research n = 26). Explanations of chronic breathlessness should use patient-centered communication; acknowledge the distress, variability, and importance of this sensation; emphasize current management principles; clarify maladaptive beliefs and expectations; and avoid moral culpability and inappropriate reassurance. Research priorities included the need 1) for a comprehensive understanding of breathlessness science; 2) to optimize, explore, and develop effective interventions, both pharmacological and nonpharmacological; and 3) determine effective models of care including strategies for education and training of health professionals and people caring for, or living with, chronic breathlessness., Conclusion: These consensus-based concepts for chronic breathlessness explanations and research provide a starting point for conversations between patients, carers, clinicians, and researchers within the chronic breathlessness community., (Copyright © 2019 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.)