Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12610000655044
Ethics application status
Approved
Date submitted
7/08/2010
Date registered
11/08/2010
Date last updated
12/03/2014
Type of registration
Prospectively registered

Titles & IDs
Public title
Consistency of the language of breathlessness between recalled and experimentally induced breathlessness in adults who are obese
Scientific title
Is the recalled sensation of breathlessness similar to the sensation experienced during exercise in adults who are overweight or obese?
Secondary ID [1] 252385 0
No secondary ID
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity 257897 0
sensation of breathlessness 257898 0
Condition category
Condition code
Diet and Nutrition 258058 258058 0 0
Obesity
Respiratory 258103 258103 0 0
Other respiratory disorders / diseases

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Submaximal exercise (2 minute step test). This test requires participants to step in place (march on the spot) raising the lifted knee to a height half way between the patella and the anterior iliac crest as many times as they can within 2 minutes. Standard heart rate and oxygen saturation will be monitored for safety. While the test has been shown to be a valid and reliable indicator of cardiovascular fitness levels in older adults and is performed as an alternative for people who cannot safely undergo common exercise tests or protocols, in this study, the 2-minute step test is not being used to assess the fitness level. It is being used to induce breathlessness in a group where exercise safety might be an issue. The test will be performed once only.
Intervention code [1] 256989 0
Early detection / Screening
Intervention code [2] 256990 0
Lifestyle
Comparator / control treatment
no exercise (retrospective recall). Participants will rest quietly in a chair for 5 minutes and then undertake a structured interview for the sensation of breathlessness while sitting comfortably in a chair. This interview assesses the recalled sensation of breathlnessness on an average day.
Control group
Active

Outcomes
Primary outcome [1] 258919 0
Intensity and unpleasentness of breathlnessness visual analogue scales (VAS)
Timepoint [1] 258919 0
baseline and immediately after cessation of exercise
Primary outcome [2] 258920 0
Descriptors of breathlessness (volunteered and selected from list of 15 statements)
Timepoint [2] 258920 0
baseline and immediately after cessation of exercise
Secondary outcome [1] 265086 0
Nil
Timepoint [1] 265086 0
Nil

Eligibility
Key inclusion criteria
Body mass index (BMI) > 25kg/m2
Willing and able to provide written consent
Minimum age
18 Years
Maximum age
80 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Body mass index (BMI) < 25kg/m2
Known pregancy
Chronic obstructive lung diseases (Forced expiratory volume in one second (FEV1) <80 per cent predicted (% pred), FEV1/Forced vital capacity (FVC) <0.7)
Prior diagnosis of heart diseases, lung cancer, severe short term memory loss or memory decline or visual impairment resulting in an inability to see the visual analogue scale (VAS)
Unable to understand English (written, spoken) or speak English

Study design
Purpose of the study
Educational / counselling / training
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Participants will be recruited from the UniSA Exercise Physiology Clinic, Royal Adelaide Hospital Obesity Clinic and previous volunteers with overweight/obesity associated with the UniSA Nutritional Physiology Research Centre (NPRC) who have expressed the willingness to be contacted for future studies. Once consent and confirmation on inclusion /exclusion criteria are completed, participants will complete baseline assessments and then complete the 2 minute step test, after which post exercise assessments will be conducted. This is a same subject, pre -post test design.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Other
Other design features
This is a same subject design where all participants receive the same interventions in the same order (recalled sensation at rest followed by sensation of breathlnessness induced by exercise ).
Phase
Not Applicable
Type of endpoint/s
Safety/efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
23/08/2010
Actual
19/11/2010
Date of last participant enrolment
Anticipated
Actual
5/07/2011
Date of last data collection
Anticipated
Actual
Sample size
Target
60
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 3125 0
5000

Funding & Sponsors
Funding source category [1] 257402 0
University
Name [1] 257402 0
University of South Australia
Country [1] 257402 0
Australia
Primary sponsor type
University
Name
University of South Australia
Address
City East Campus, North Terrace
Adelaide, South Australia 5000
Country
Australia
Secondary sponsor category [1] 256673 0
None
Name [1] 256673 0
Address [1] 256673 0
Country [1] 256673 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 259427 0
Human Research Ethics Committe, University of South Australia
Ethics committee address [1] 259427 0
Mawson Lakes Campus
University of South Australia
Ethics committee country [1] 259427 0
Australia
Date submitted for ethics approval [1] 259427 0
Approval date [1] 259427 0
28/08/2008
Ethics approval number [1] 259427 0
P202/08

Summary
Brief summary
Emerging evidence has suggested that the sensation of breathlessness includes domains for intensity, sensory quality (descriptors) and unpleasantness).The sensation of breathlessness differs between people with and without chronic medical conditions and is thought to reflect the different mechanisms initiating the sensation. While breathlessness is common in people who are overweight/ obese, to date, no previous study could be found which specifically describe the sensory quality of breathlessness in this population. It is unclear whether the sensation of breathlessness experienced by people who are overweight/obese is unpleasant and if so, does this unpleasant sensation encourage early cessation of physical activity. There is a difference in the sensory quality between recall and exercise-induced breathlessness in people with chronic pulmonary disease. This might be simply due to the difference in the context under which breathlessness was recalled or induced. However, influence of the memory, emotion, expectation, and other psychological factors could very well play a role.

This uncontrolled pre-post design aims to determine whether the recalled sensation of breathlessness differs from the sensation induced by exercise in adults with overweight or obesity.
Sixty people between the ages of 18 and 80 years with overweight /obesity (BMI kg/m2 >25) will be invited to participate in this study. Participants will be excluded if they have a prior diagnosis of heart disease, lung cancer, chronic obstructive pulmonary disease, memory or cognitive disorders or a visual disorder which limits the ability to interpret visual analogue scales.
After height, body mass and body mass index have been assessed, participants will complete a structured interview for the sensation of breathlessness before and immediately after breathlessness in induced by a 2 minute step test. This interview includes assessment of breathlessness intensity (visual analogue scale), unpleasantness(visual analogue scale) and sensory quality (descriptors volunteered and selected from a pre-existing list of 15 breathlessness statements).
Descriptive analysis (e.g. mean, standard deviation, frequency) are planned for age, gender, weight, height and BMI. Paired t-test will be performed between baseline and exercise-induced VAS scores to determine the degree of breathlessness induced by the 2-minute step test. The frequency of descriptors volunteered and endorsed by each subject will be allocated into sensory categories. Language data will then be converted to a binary form (subjects do or do not volunteer or endorse a particular language category). Within each sensory category, the difference between the recalled and exercise-induced language will be compared using McNemar’s test, with p < 0.05 regarded as significant.
Trial website
nil
Trial related presentations / publications
Williams MT, Cafarella P, Olds T et al. Affective descriptors of the sensation of breathlessness are more highly associated with severity of impairment than physical descriptors in people with chronic obstructive pulmonary disease. Chest. Published Online first: 4 Mar 2010. doi: 10.1378/chest.09-2498 Williams MT, Garrard A, Cafferela P, Petkov J, Frith P. Quality of recalled dyspnoea is different from exercise-induced dyspnoea: an experimental study Australian Journal of Physiotherapy 2009 55;177-183 Williams MT, Cafarella P, Olds T, Petkov J, Frith P. The language of breathlessness differentiates between patients with chronic obstructive pulmonary disease and age-matched adults. Chest 2008;134:489-496
Gerlach Y, Williams MT, Coates A. Weighing up the evidence –A systematic review of measures used for the sensation of breathlessness in obesity. International Journal of Obesity 2013 37:341-349
Gerlach Y, Williams MT, Coates A. Measures of the sensation of breathlessness in people with obesity: a systematic review. Physiotherapy Conference Brisbane October 27-30th 2011.
Public notes

Contacts
Principal investigator
Name 31481 0
Dr Marie Williams
Address 31481 0
School of Population Health,Division of Health Sciences, University of South Australia, P4-27D Playford Building, City East Campus , Adelaide , South Australia 5000
Country 31481 0
Australia
Phone 31481 0
+61 8 8302 1153
Fax 31481 0
Email 31481 0
[email protected]
Contact person for public queries
Name 14728 0
Dr Dr Marie Williams
Address 14728 0
School of Population Health,Division of Health Sciences, University of South Australia, P4-27D Playford Building, City East Campus , Adelaide , South Australia 5000
Country 14728 0
Australia
Phone 14728 0
+61 8 8302 1153
Fax 14728 0
+61 8 8302 2794
Email 14728 0
[email protected]
Contact person for scientific queries
Name 5656 0
Dr Dr Marie Williams
Address 5656 0
School of Population Health,Division of Health Sciences, University of South Australia, P4-27D Playford Building, City East Campus , Adelaide , South Australia 5000
Country 5656 0
Australia
Phone 5656 0
+61 8 8302 1153
Fax 5656 0
+61 8 8302 2794
Email 5656 0
[email protected]

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