Assessment of functional capacity in low-resource settings – adapted six-minute walk tests

Date
2021-03
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH SUMMARY : Background: Measuring functional capacity is an important assessment tool that aids researchers and clinicians in determining the diagnosis, prognosis, and management of patients in various populations. The gold standard for functional capacity testing is cardiopulmonary exercise testing. However, this test requires specialised equipment and trained staff, and is therefore not readily available in many clinical settings. The 6-minute walk test (6MWT) is used as a validated alternative, requiring minimal resources or training. In 2002 the American Thoracic Society (ATS) published guidelines to standardise the implementation of the test. However, considering several constraints, especially within the context of ow-resource settings (LRS) researchers and clinicians alike have had to adapt the methods used when implementing the test. Using different methods for the same test may limit the interpretation and clinical applications of the test. The aim of this theses is to evaluate the application and protocols used for the 6-minute walk test within LRS. Methods: A scoping review was undertaken to identify published studies that implement adapted protocols when conducting the 6MWT. Additionally, the rationale for these adaptations were investigated. Five electronic databases were accessed and searched from inception to October 2019. Data concerning the study source, participants, reported 6MWT purpose, variations (e.g. course length), 6MWT outcome, and rationale for making protocol adaptations were extracted. The findings in this study were used to inform the development of a cross-sectional study with the aim to determine the agreement between the ATS standard 30m 6MWT pathway, a 10m straight and a 10m figure-ofeight pathway, in patients with non-communicable disease. Results: The search returned 564 records of which 22 studies were included. Studies were predominantly conducted in lower-middle income countries. The most common adaptation made to ATS guidelines was course length, being either shorter or longer than the standard 30 meters. Few studies (n = 8, 36%) provided a rationale for adapting the 6MWT. However, based on these eight studies, space limitations was the most common argument for making adaptations. Subsequently, we recruited 27 patients with one or more non-communicable disease to perform two 6MWTs. Fifteen participants performed both a 30 meter straight and a 10m straight 6MWT and twelve participants performed a 30m straight and a 10mfigure-of-eight 6MWT. Regardless of chosen configuration (10m figure-of-eight versus 10m straight), a shortened 6MWT pathway resulted in a significantly smaller 6-minute walk distance. Moreover, the difference was larger than the reported minimal clinically important difference thereby highlighting the clinical implications of adapting the 6MWT. Conclusion: Strict adherence to the ATS guidelines for conducting the 6MWT is challenging. Common adaptations included a change in course length and/or course configuration (chapter 2), with such adaptations having clinically relevant implications to the outcome of the 6WMT (chapter 3). This provides limitations to the application and interpretation of the test. Researchers and clinicians need to take this into consideration when adapting the protocol used for the 6MWT. Reference equations that take into account the adaptations should be considered. However, accounting for every variation of the test may not be feasible. Alternative tests for functional capacity testing within the context of LRS may be a more practical solution.
AFRIKAANSE OPSOMMING : Agtergrond: Die evaluering van funksionele kapasiteit is 'n belangrike assesseringsinstrument wat navorsers en gesondheidswerkers help om die diagnose, prognose en behandeling van pasiënte in verskillende populasies te bepaal. Die goue standaard vir funksionele kapasiteitstoetse is kardiopulmonale oefentoetsing. Hierdie toets benodig egter gespesialiseerde toerusting en opgeleide personeel, en is nie altyd toeganklik in alle kliniese omgewings nie. Die 6-minute staptoets (6MWT) word as 'n geldige alternatief gebruik, wat minimale hulpbronne of opleiding benodig. In 2002 het die Amerikaanse Torakale Assosiase (ATS) riglyne gepubliseer om die implementering van die toets te standaardiseer. In die lig van verskeie beperkings, veral binne die konteks van instellings met lae hulpbronne (LRS), moes navorsers en gesondheidswerkers egter die tegniek wat gebruik is tydens die implementering van die toets, aanpas. Die gebruik van verskillende tegnieke vir dieselfde toets kan die interpretasie en kliniese toepassings van die toets beperk. Die doel van hierdie riglyne is om die toepassing en tegniek van die ses minute staptoets binne LRS te evalueer. Metode: 'n Omvattende literatuur studie is onderneem om gepubliseerde studies te identifiseer wat aangepaste protokolle implementeer tydens die uitvoering van die 6MWT. Die rasionaal van hierdie aanpassings was ook ondersoek. Vyf elektroniese databasisse was identifiseer en ondersoek vanaf insepsie tot Oktober 2019. Data rakende die studiepopulasie, deelnemers, gerapporteerde 6MWTdoel, variasies (bv. lengte), 6MWT-uitkoms en rasionaal vir die aanpassing van protokol was identifiseer. Die bevindings in hierdie studie is gebruik om die ontwikkeling van 'n dwarsdeursneestudie in te lig met die doel om die ooreenstemming tussen die ATS-standaard 30m 6MWT-bane en 'n 10m-reguit- en 'n 10m-syfer-van-agt-roete te bepaal, by pasiënte met nie -oordraagbare siektes. Resultate: Die soektog het 564 studies identifiseer waarvan 22 studies ingesluit is. Die studies was hoofsaaklik in laer- tot middelinkomste lande gedoen. Die algemeenste aanpassing aan die Amerikaanse Torakale Assosiasie (ATS) -riglyne was die lengte van die baan, of dit was korter of langer as die standaard 30 meter. Minimale studies (n = 8, 36%) verskaf 'n rede vir hierdie aanpassing van die 6MWT. Van die agt studies was ruimtebeperkings egter die algemeenste probleem om aanpassings te maak. Dus het ons 27 pasiënte met een of meer nie-oordraagbare siektes ingesluit om twee 6MWT's uit te voer. Vyftien deelnemers het beide 'n 30 meter reguit en 'n 10 m reguit 6MWT uitgevoer en twaalf deelnemers het 'n 30 m reguit en 'n agt figuur van agt 6 MWT uitgevoer. Ongeag die aanbeveelde struktuur (10m figuur van agt versus 10m reguit), 'n verkorte 6MWT-baan het gelei tot 'n aansienlik kleiner loopafstand van 6 minute. Die verskil was boonop groter as die gerapporteerde minimale klinies belangrike verskil. Hierdie bevindinge beklemtoon die kliniese implikasies van die aanpassing van die 6MWT. Gevolgtrekking: Streng toepassing van die ATS-riglyne vir die uitvoering van die 6MWT is uitdagend. Algemene aanpassings het 'n verandering in lengte en/of konfigurasie ingesluit (Hoofstuk 2), met sodanige aanpassings wat klinies relevante implikasies het vir die uitkoms van die 6WMT (Hoofstuk 3). Dit beperk die toepassing en interpretasie van die toets. Navorsers en gesondheidswerkers moet dit in ag neem wanneer hulle die tegniek van die 6MWT aanpas. Verwysingsvergelykings wat die aanpassings in ag neem, moet oorweeg word. Om elke variasie van die toets te bereken, is egter nie moontlik nie. Alternatiewe toetse vir funksionele kapasiteitstoetse binne die konteks van LRS kan 'n meer praktiese oplossing wees.
Description
Thesis (MScPhysio)--Stellenbosch University, 2021.
Keywords
Functional capacity exam -- Developing countries, Cardiopulmonary fitness -- Measurement -- Developing countries, Physical fitness -- Measurement -- Developing countries, UCTD
Citation