Breathlessness Perceptions Within Respiratory Diseases (BiRD)

Exploring Differences in Breathlessness Perceptions Within Respiratory Diseases

Breathlessness is a complex symptom that results in poor quality of life, increased hospitalisations and increased mortality. Breathlessness is influenced by physiological, psychological and functional factors but these are poorly explored. There are also unexplored phenomenon's such as breathing pattern. Therefore, this study aims to understand the influences of physiology, psychology, function and breathing pattern on health related quality of life in those with a respiratory disease compared to healthy controls. This project is a cross-sectional cohort study including those with a known respiratory disease and experiencing breathlessness, compared to non-breathless healthy controls. The investigators will measure your physiology through spirometry (a breathing test that tells us about their lung function), psychology through questionnaires, function through an exercise test and breathing pattern using opto-electrictronic plethysmography (markers are placed on your chest to see how participants breathe while exercising). This will be conducted over two visits. The investigators will recruit participants from clinics at the University Hospitals of Leicester NHS Trust. The investigators are aiming to recruit 50 participants with a respiratory disease and 25 healthy controls. The results of this study will help us understand breathlessness in more detail in order to be able to develop better treatments.

Study Overview

• Status: Recruiting
• Conditions: Bronchiectasis; Chronic Obstructive Pulmonary Disease (COPD); Interstitial Lung Disease (ILD); Asthma (Diagnosis); Breathing Pattern Disorder

Detailed Description

Breathlessness is a debilitating symptom that results in poorer quality of life, increased hospitalisations, and increased mortality. Breathlessness is a complex multi-dimensional sensation with established bio-psycho-social influences (Hayen et al., 2013) that are likely to interact, though the mechanisms or relative contributions of these interactions are unknown (Oxley & Macnaughton, 2016). Breathlessness is a hallmark feature of respiratory disease and is the primary reason for seeking healthcare advice and treatments. Though currently breathlessness management follows a one-size fits all approach and does not pay consideration to the unique and individual experience of breathlessness.

The breathing thinking functioning (BTF) model of breathlessness is a theoretical framework that attempts to explain this complex and multifactorial symptom, however it lacks scientific premise. Highlighting that physiology, psychology and function will all play a role in determining breathlessness for the individual. An additional complication, that is seldom explored is disordered breathing patterns. This is potentially bi-directional where by severe breathlessness could contribute to disordered breathing and/or disordered breathing could lead to severe breathlessness. There is currently no objective marker of disordered breathing pattern however, use of optoelectronic plethysmography (OEP) has shown promise in quantifying this phenomenon (Smyth, 2021). OEP is a novel technique, utilising 3-dimensional motion capture, and can be measured during exercise, using a cardiopulmonary exercise testing, which allows for monitoring of breathlessness and breathing pattern during exercise, commonly reported as troublesome by patients. OEP has been used in Chronic Obstructive Pulmonary Disease to assess hyperinflation, though evidence within respiratory disease is at its infancy, and has not been explored alongside other factors to understand the contribution of multiple factors of breathlessness. Therefore, there is a current gap in the literature exploring the interaction(s) of factors contributing to breathlessness severity, including the objective analysis of breathing pattern. Further understanding the breathlessness in this way could lead to personalisation or treatments increasing their effectiveness, and improving health and quality of life. The project will quantitatively measure breathlessness perception, alongside objective cardiorespiratory measures and background health and well-being data as well as OEP breathing pattern data (such as compartment contribution and inter-compartment asynchrony). This will allow an understanding of how each of these factors may affect interventions and differences in breathlessness experience and presentation, and subsequently the acceptability of breathlessness.

• Study Type: Observational
• Enrollment (Estimated): 75

Contacts and Locations

• Study Contact: Name: Enya Dr. Daynes, PhD; Phone Number: +44 0116 273 0333; Email: e.daynes@nhs.net
• Study Contact Backup: Name: Iridu Udanthi Basnayake, MSc; Phone Number: 0116 273 0333; Email: iub3@leicester.ac.uk

Study Locations

• United Kingdom
  • Leicestershire
    • Leicester, Leicestershire, United Kingdom, LE3 9QP
      • Recruiting
      • Glenfield Hospital
      • Contact: Enya Daynes, PhD; Phone Number: +44 +44 1162730333; Email: e.daynes@nhs.net
      • Principal Investigator: Enya Daynes, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of a healthy group and a disease group. The disease group will have a known respiratory condition such as COPD, Asthma, ILD or Bronchiectasis. The healthy group will not have any functionally limiting conditions interms, cardiorespiratory and muskuloskeletal.

Description

Inclusion Criteria:

• • Aged 18 or over up to 100

  • Known respiratory diagnosis* OR Healthy control**
  • Ongoing symptoms of breathlessness defined as ≥2 MRC dyspnoea scale
  • Able to communicate in English
  • Able to attend two study visits

  • Able to provide written informed consent

    • Known respiratory diagnosis could include, but is not limited to, COPD, Asthma, Bronchiectasis or ILD.
    • Healthy controls are required to have an absence of a functionally limiting condition such as respiratory, cardiovascular, or musculoskeletal.

Exclusion Criteria:

• • Unstable disease or undergoing investigations for unexplained symptoms

  • Undergone a surgery within past six weeks
  • Contraindications for exercise outlined by ACSM guidelines (Unstable CVD, hypertension etc)
  • BMI ≥ 35kg/m2
  • Unable to communicate in English
  • Unable to provide written informed consent
  • Unable to abstain from smoking for 8 hours prior to testing

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

50 participants with a respiratory disease and 25 health controls will be recruited.; Inclusion criteria is: Aged 18 or over up to 100; Known respiratory diagnosis* OR Healthy control**; Ongoing symptoms of breathlessness defined as ≥2 MRC dyspnoea scale; Able to communicate in English; Able to attend two study visits; Able to provide written informed consentKnown respiratory diagnosis could include, but is not limited to, Chronic Obstructive Pulmonary Disease, Asthma,Bronchiectasis or Interstitial Lung Disease.Healthy controls are required to have an absence of a functionally limiting condition such as respiratory, cardiovascular, or musculoskeletal. Participants are excluded if,: Unstable disease or undergoing investigations for unexplained symptoms; Undergone a surgery within past six weeks; Contraindications for exercise outlined by American College of Sports Medicine guidelines (Unstable Cardiovascular disease, hypertension etc); Body Mass Index ≥ 35kg/m2; Unable to communicate in English; Unable to provide consent

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Breathing pattern regional contribution parameters	Optoelectronic plethysmography allows to quantify how different thoracic compartments contribute to the overall tidal volume through regional contribution parameters. These regional contributions are expressed as percentages.	From June 2025 to July 2026

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Breathing pattern-Timing parameters-Recording duration	The duration will be recorded in minutes and seconds to state how long a specific measurement lasted.	From June 2025 to July 2026
Breathing pattern-Timing parameters- Sampling frequency rate	This is one of the core timing parameter. The system uses sample at 60-120 Hz (frames per second).	From June 2025 to July 2026
Breathing pattern-Timing Parameters- Number of respiratory cycles analysed	This parameter is important to give an indication of data adequacy. It will be reported in whole numbers.	From June 2025 to July 2026
Breathing pattern-Ratio parameters-Compartmental contributions	All the parameters will be expressed as percentages. (%RCp, %RCa and %AB) typically ranging from (0-100%)	From June 2025 to July 2026
Breathing pattern- Phase angle parameters	These parameters will be meausred by the degree ranging from 0 to 180 (Complete paradox)	From June 2025 to July 2026
Breathing pattern-ratio parameters- Temporal ratios	This will be reported in decimal values. (Ti/Ttot, Ti/Te ratio, IE ratio inverse of Ti/Te) Ti-Inspiratory time Te-Expiratory time Ttot-Total breath duration	From June 2025 to July 2026
Rate of Perceived Exertion (RPE) and Borg breathlessness scale	Provides details about how breathlessness one feels and how hard the exercise is during exercise . Both these scales will be reported in numbers. The RPE is from 6-20 and the Borg scale is from 0-10. Higher scores will indicate worst breathlessness and exertion from the performing exercise.	From June 2025 to July 2026
Spirometry	Lung Function parameters such as FEV1 -Forced Expiratory Volume, FVC -Forced Vital Capacity, FEV1/FVC ratio will be obtained using Spirometry (Spirotrac). Presented in litres can be converted to percentage. Depending on the guidelines usually if the FEV1/ FVC ratio<= 0.7 it can be said that there is an airway obstruction. Lower value indicates a higher level of breathlessness. The GOLD classification criteria is usually used to describe the severity. The values can further be explained as obstructive or restrictive by looking at the FVC%. A lower FVC% predicted will indicate worse restriction.	From June 2025 to July 2026
Modified Medical Research Council Dyspnea Scale (mMRC)	Scale that grades the severity of breathlessness based on the level of physical activity that provokes the symptom. The scale is from 0-4. Lower values indicate less severity of breathlessness while higher values indicate severe breathlessness.	From June 2025 to July 2026
Dysponea-12 (D-12)	The Dyspnoea-12 (D-12) is a patient-reported outcome measure designed to assess the multidimensional nature of breathlessness severity through both physical and affective components. The questionnaire has 12 questions where the participant will be asked to put a tick to any box from none, mild, moderate and severe.	From June 2025 to July 2026
Hospital Anxiety and Depression Scale (HADS)	Self-report questionnaire designed to screen for clinically significant anxiety and depression in medical populations. The participant will be asked to underline their answers for all the questions. The questionnaire includes a 'A' category and a 'D' category. Scores are given to both catergories from 0-3. At the end the two catergoeies will be calculated separately.	From June 2025 to July 2026
Breathlessness catastrophising scale (BCS)	A measure designed to assess catastrophic thinking patterns specifically related to breathlessness. BCS is a 13 item questionnaire where the participant will have to tick one of the boxes for each question starting from not at all, to a slight degree, to a moderate degree, to a great degree and all the time.	From June 2025 to July 2026
Euroqol 5-Domain-5-Level (EQ5D-5L)	A standardised generic health-related quality of life instrument designed to provide a simple, comprehensive measure of health status across diverse populations and conditions. The questionnaire asseses 4 sections where the participant will have to select one option from each section. The questionnaire is assessing the health related quality of life interms of that day and not in general. At the end of the questionnaire there is a separate scale from 0-100 where the participant will have to place an x mark on the scale and write that score in a box which will indicate how they feel on that specific day.	From June 2025 to July 2026
Nijmegen Questionnaire (NQ)	An instrument designed to assess symptoms associated with hyperventilation syndrome and dysfunctional breathing patterns. The questionnaire contains 16 symptoms. The participant will be required to place a tick in one of the boxes for each question. Answers include, never, rarely, sometimes, often and very often.	From June 2025 to July 2026
Breathing pattern assessment tool (BPAT)	Visible characteristics of breathing patterns during rest where the participant will be asked to rest against a back seat. The participant will be observed for 1 minute by a member of the study team where they will have to breathe in and out as they usually do. During that time the team member will observe whether the breathing is rhythmical, whether the participant is using using their chest, abdomen or both for breathing, whether their inspiratory and expiratory flows are silent, audible or loud. Other questrions that will be answered by the team member would be channel of inspiration and expiration, air hunger, rhythm as well the team member will also calculate the respiratory rate within a 1 minute. Scores will be given from 0-2 and at the end the total score will be calculated.	From June 2025 to July 2026
Cardiopulmonary Exercise testing -Gas Exchange Parameters	Peak Oxygen Uptake (VO2 peak) meausured through mL/min or L/min, If >=85 is normal, 65-84 is mildly reduced, 50-64 is moderately reduced and <50 is severely reduced. Carbon Dioxide Output (VCO2) and RER (VCO2/VO2) meausured through mL/min or L/min, VCO2 roughly rises parallel to VO2. The volume of CO₂ produced per minute by the body reflects the metabolic CO₂ production from aerobic and anaerobic metabolism combined. The respiratory exchange ratio which is RER gives a clear indication whether the test was maximal effort or not. RER >=1.10 is the key cutoff. AT will all be meausured through mL/min or L/min. Normal: typically > 40% of predicted VO₂ max, or ≥ 11 ml/kg/min Higher AT = better - indicates the body can sustain aerobic metabolism at higher workloads before switching to anaerobic system.	From June 2025 to July 2026
Cardiopulmonary Exercise Testing- Ventilatory Parameters (Minute Ventilation)	Minute Ventilation will be measured at maximal exercise. The measures will be stated in L/min. Minute ventilation is assess the ventilatory capacity. Usually the ventilatory reserve utilizes <60 to 70% of the maximum voluntary ventilation which is considered healthy.	From June 2025 to July 2026
Cardiopulmonary Exercise Testing- Ventilatory Parameters (Tidal Volume)	Tidal Volume will be measured by L or mL. It is amount of air that moves in and out of the lung. During exercise, it increases linearly before plateauing indicating whether a participant's exercise capacity is physically restricted due to lung mechanics.	From June 2025 to July 2026
Cardiopulmonary Exercise Testing- Ventilatory Parameters ( Respiratory Rate)	This is measured by breaths per minute. The amount of breaths taken will indicate how your brain and lungs are functioning to clear the carbondioxide which will help to maintain the chemical balance. Resting phase 12 to 20 breaths/min -Baseline range Peak Exercise 35 to 45 breaths/min -Normal physiological range for healthy adults.	From June 2025 to July 2026
Cardiopulmonary Exercise Testing-Ventilatory Parameters (MVV and BR)	MVV- Maximal Voluntary Ventilation and BR-Breathing Reserve both are measured by L/min. This determines whether a patient's exercise capacity is limited by their lungs or by their heart and/or muscles. MVV represents a participants absolute ceiling for breathing capacity, while BR measures how much of that capacity is left over at peak exercise. If MVV >=80% it is considered good and if <80% it is considered bad. Whereas for BR, if >11L/min is considered as the lungs still having more capacity left after exercising and <=11L/min is considered that the patient is exhausted and their breathing capacity has reached the limit.	From June 2025 to July 2026
Cardiopulmonary Exercise Testing- Ventilatory Efficiency Parameters	VE/VO2 slope and VE/VCO2 at AT are measured by a dimensionless ratio. VE/VCO2 is considered good when it is between 23-30 and bad when it is >34. VE/VO2 is considered good when it is between 25 to 33 and bad when it is >36	From June 2025 to July 2026
Cardiopulmonary Exercise Testing-HR reserve	This will be measured through bpm. It is the difference between predicted maximum heart rate and the actual peak heart rate. <15bpm indicates a good response whereas >=15bpm indicates a poor response.	From June 2025 to July 2026
Cardiopulmonary Exercise Testing- Work Rate	This will be reported in W (Watts). Achieving >= 80% of the predicted work rate is considered a good response whereas <80% would be considered as a poor response.	From June 2025 to July 2026
Oxygen Saturation	This will be reported through % (Percentage). 95-100%- Good 93-94%- Borderline <92%- Bad	From June 2025 to July 2026
Blood pressure	This will be measured by mmHg Before the test (At rest) >=200/110- Contraindication not to perform the exercise test <90/60- Too low for the baseline During the exercise test, If the systolic value exceeds 190 or 210 indicates a severe hypertension A critical stop would be a systolic value exceeding 250 or a diastolic value exceeding 115. After the test, The blood pressure should return to near or actual borderline taken during rest.	From June 2025 to July 2026
Height	Measured through cm.	From June 2025 to July 2026
Weight	Measured by kg (Kilograms).	From June 2025 to July 2026
Body Mass Index	Calculated manually via height and weight measurements. Will be presented as kgm squared. This study has a cut off value which is not involving participants above 35.	From June 2025 to July 2026
Heart rate variability (HRV) - Holter Monitor	SDNN- Standard Deviation of normal-to-normal R-R intervals, SDANN-Standard Deviation of the mean R-R intervals, RMSSD-Square root of the mean squared difference of successive R-R intervals are all measued by milliseconds (ms).	From June 2025 to May 2026
Heart Rate Variability-Holter Monitor	LF-Low Frequency Power and HF-High Frequency Power are both measured by milliseconds squared or absolute units. LF Absolute 300 to 1500- considered good LF Absolute <100 -considered bad/abnormal HF Absolute 200 to 1000- considered good HF Absolute <50- considered bad/abnormal	From June 2025 to July 2026
Heart Rate Variability-Holter Monitor	LF/HF ratio will be a dimensionless ratio represented without any units. High rates will suggest of sympathetic predominance. At rest Good range will be 1.0-2.0 Bad range >5 or <0.5	From June 2025 to July 2026

Collaborators and Investigators

• Sponsor: University Hospitals, Leicester
• Investigators: Principal Investigator: Enya Daynes, PhD, University Hospitals, Leicester

Publications and helpful links

General Publications

• Pritchard A, Burns P, Correia J, Jamieson P, Moxon P, Purvis J, Thomas M, Tighe H, Sylvester KP. ARTP statement on cardiopulmonary exercise testing 2021. BMJ Open Respir Res. 2021 Nov;8(1):e001121. doi: 10.1136/bmjresp-2021-001121.
• Oxley R, Macnaughton J. Inspiring change: humanities and social science insights into the experience and management of breathlessness. Curr Opin Support Palliat Care. 2016 Sep;10(3):256-61. doi: 10.1097/SPC.0000000000000221.
• Hayen A, Herigstad M, Pattinson KT. Understanding dyspnea as a complex individual experience. Maturitas. 2013 Sep;76(1):45-50. doi: 10.1016/j.maturitas.2013.06.005. Epub 2013 Jul 10.

Study record dates

Study Major Dates

• Study Start (Actual): June 6, 2025
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 1, 2026

Study Registration Dates

• First Submitted: December 31, 2025
• First Submitted That Met QC Criteria: June 10, 2026
• First Posted (Actual): June 15, 2026

Study Record Updates

• Last Update Posted (Actual): June 15, 2026
• Last Update Submitted That Met QC Criteria: June 10, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Heart rate variability; Breathlessness; Respiratory diseases; Cardiopulmonary Exercise Testing; OEP; Breathing patterns
• Additional Relevant MeSH Terms: Pathologic Processes; Chronic Disease; Disease Attributes; Immune System Diseases; Lung Diseases; Respiration Disorders; Bronchial Diseases; Lung Diseases, Obstructive; Respiratory Hypersensitivity; Hypersensitivity, Immediate; Hypersensitivity; Signs and Symptoms, Respiratory; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pulmonary Disease, Chronic Obstructive; Asthma; Disease; Lung Diseases, Interstitial; Respiratory Tract Diseases; Dyspnea; Bronchiectasis
• Other Study ID Numbers: 172675; NIHR203327 (Other Grant/Funding Number: NIHR Biomedical Research Centre Leicester)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Once participnats enrolled the data were anonymised. All the outcome measure data will be made available and kept within a locked UHL cabnited and password protected computer for future study purposes.
• IPD Sharing Time Frame: Start Date -June 2025 to June 2030
• IPD Sharing Access Criteria: The study team will be able to access the data.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No