A MODIFIED SIX-MINUTE WALK TEST (6MWT) FOR LOW-RESOURCE SETTINGS - A CROSS-SECTIONAL STUDY

B. Fell¹, S. Hanekom¹, M. Heine^2,3

¹Stellenbosch University, Health and Rehabilitation Sciences, Division of Physiotherapy, Cape Town, South Africa, ²Stellenbosch University, Health and Rehabilitation Science, Cape Town, South Africa, ³University Medical Center Utrecht, Julius Global Health, Utrecht, Netherlands

Background: The 6 min walk test (6MWT) is a validated tool used to objectively assess functional capacity in a variety of patient populations. Despite the apparent ease in conducting the 6MWT, space constraints in low-resource settings, often limit the practicality of the 6MWT according to the standard (2002) American Thoracic Society protocol. Adaptations to this protocol are common however, while pragmatic there are potential implications for research and clinical practice. Furthermore, such implications for research and clinical practice may be augmented in low-resourced settings.

Purpose: To determine the agreement between the 6 min walk distance (6MWD) achieved on the standard 30 m (6MWT30) as per the ATS guidelines, and a straight 10 m (6MWT10), or 10 m figure-of-eight (6MWTF8) configuration, respectively in an adult population with one or multiple non-communicable diseases (NCD) for which the 6MWT is commonly used.

Methods: This cross-sectional study is a sub-analysis of a randomised feasibility trial conducted in Cape Town South Africa. Ethical approval was obtained from Stellenbosch University Health Research and Ethics Council (M17/09/031). The study was conducted in a socioeconomic challenged community in Cape Town between January – December 2019. A heterogeneous sample of adults (n = 27) were randomized into performing, on the same day, the 6MWT10 (n = 15) or 6MWTF8 (n = 12), in addition to the standard 6MWT30. Pairwise comparison and concordance correlation coefficients were used to assess agreement.

Results: The mean (SD) 6MWD30 was 437(42) meters, while the mean 6MWD10 was 371(57). The mean difference (SE; p-value) between the 6MWD30 and 6MWD10 was 67 m (8.6; p .01). The mean 6MWD30 was 424 (67) meters, while the mean 6MWDF8 was 347(58). The mean difference between the 6MWD30 and 6MWDF8 was 77 m (6.0; p .01). Moderate concordance was found between the 6MWT30 and 6MWTF8 or 6MWD10, respectively.

Conclusions: The present data suggest that independent of configuration, requiring hard turns (6MWT10) or soft turns (6MWTF8), using a shorter pathway significantly reduced the 6MWD relative to the expected 6MWD of the ATS standard 6MWT30. Low-resource settings may benefit from contemporary measures of functional capacity more conducive to resource constraints, or standardization of the test when used in such settings.

Implications: When conducting the 6MWT, clinicians and researchers need to be cognizant of the adaptations they implement; especially when interpreting the 6MWD results and using it to determine prognosis and inform exercise prescription. Additionally, it is important to ensure thorough especially for the continuum of care and for others intending to adopt similar methods for a specific population.

Funding acknowledgements: This work is supported by the AXA Research fund, Grant No. S005459

Keywords:
Non-communicable disease
Rehabilitation
Exercise testing

Topics:
Non-communicable diseases (NCDs) & risk factors
Community based rehabilitation
Primary health care

Did this work require ethics approval? Yes

Institution: Stellenbosch University

Committee: Stellenbosch University Health Research and Ethics Council

Ethics number: (M17/09/031)