Feasibility study assessing 6MWT as a CRF screening tool
Research type
Research Study
Full title
To assess the feasibility of using the 6 minute walk test during a patients first visit to surgical outpatient clinic to identify those individuals with a significantly reduced level of cardiorespiratory fitness.
IRAS ID
265798
Contact name
Karen Kerr
Contact email
Sponsor organisation
Sheffield Teaching Hospitals NHS FT
Clinicaltrials.gov Identifier
Duration of Study in the UK
0 years, 8 months, 1 days
Research summary
Research Summary
]
Our aim is to assess the usefulness of a simple walk test (the 6 minute walk test) as a fitness test for those destined for major abdominal surgery when they attend our hospital for the first time to identify those patients who are ‘fit’. The fittest patients are expected to do better after major abdominal surgery and need less time and resources directed at them than those less fit to achieve good outcomes after surgery.
Identifying the fit allows us to identify the less fit. Other centres have shown the less fit to benefit from methods to improve fitness before major abdominal surgery. If we can successfully identify Sheffield’s less fit patients at their first visit to the surgical outpatients department then this will provide us more time to improve their fitness before surgery which should see them have better results after surgery.
One centre, Middlesbrough, has reported that for them it was possible to spot the fitter patients from the distance walked. What is not known is wither the distance walked by the fittest in Middlesbrough would be the same as Sheffield. We also don’t know if it is possible to have patients do the walk test on their first visit to hospital and if they did walk would we be able to identify the fittest patients so that we could start focusing resources on the less fit at the time of first visit. We aim to see how much time that would give us to get patients fitter before surgery and finally we aim to check that those that walked the furthest were in fact the fittest by comparing for those patients who will undergo a cardiopulmonary exercise test as routine care the distance walked with their objectively measured fitness.Summary of Results
During the year that the study ran; 8th March 2021 to 7th March 2022 a total of 365 individuals were identified; 65 men and 50 women were excluded. Two hundred and fifty individuals consented; 125 male and 125 female to undergo a six-minute walk test (6MWT) and have their 6-minute walk distance (6MWD) recorded.
The average time taken to perform the 6MWT is 9.6 ± 2.1min with the test requiring an additional explanation for 2 of the 250 participants. The ease of the test has been calculated by adding together the walker and participant scores; 1 equating to very easy and 5 equating to very hard and dividing them by the number of participants for the mean score per participant.
A 6MWD was recorded for each participant, the average 6MWD being 398m ± 109m. The difference between the mean male and female 6MWD is 12.85m. For Sheffield the threshold distance could be calculated from the distance achieved by those 25 individuals in both sexes that walked the furthest: the top 20%. For men that distance is 484m and for women that distance is 473m. The difference in threshold distance between the sexes calculated this way is 11m. If we apply the female threshold distance to the men in this sample, then 31 men have crossed the threshold. If we apply the male threshold to the females in this sample, then 18 females cross the threshold. The top 20% was chosen as a previous analysis of the fitness of the Sheffield non-cardiopulmonary surgery population had revealed a cardiorespiratory fitness as measured by the peak oxygen consumption during CPET that was at levels that conveyed protection from harm in the top 20%.
For institutions without access to their own historical data the threshold distance could also have been calculated from the mean 6MWD plus one standard deviation from the mean; for men that distance is 512.5m and for women that distance is 500.5m. For both sexes in this studied population that is 17 patients in each who could be considered ‘fit’.REC name
London - Chelsea Research Ethics Committee
REC reference
20/LO/0663
Date of REC Opinion
25 Jun 2020
REC opinion
Further Information Favourable Opinion