Assessing a GPS-Based 6-Minute Walk Test for People With Persistent Pain: Validation Study

Joshua Simmich; Nicole Emma Andrews; Andrew Claus; Megan Murdoch; Trevor Glen Russell

doi:10.2196/46820

Assessing a GPS-Based 6-Minute Walk Test for People With Persistent Pain: Validation Study

JMIR Form Res. 2024 Mar 18:8:e46820. doi: 10.2196/46820.

Authors

Joshua Simmich^{1

2}, Nicole Emma Andrews^{1

2

3

4}, Andrew Claus^{3

5}, Megan Murdoch^{3

6}, Trevor Glen Russell^{1

2}

Affiliations

¹ RECOVER Injury Research Centre, Faculty of Health and Behavioural Sciences, The University of Queensland, Brisbane, Australia.
² STARS Education and Research Alliance, Surgical Treatment and Rehabilitation Service, The University of Queensland and Metro North Health, Brisbane, Australia.
³ The Tess Cramond Pain and Research Centre, Royal Brisbane and Women's Hospital, Metro North Hospital and Health Service, Brisbane, Australia.
⁴ Occupational Therapy Department, Royal Brisbane and Women's Hospital, Metro North Hospital and Health Service, Brisbane, Australia.
⁵ School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Australia.
⁶ Physiotherapy Department, Royal Brisbane and Women's Hospital, Metro North Hospital and Health Service, Brisbane, Australia.

PMID: 38498031
PMCID: PMC10985605
DOI: 10.2196/46820

Abstract

Background: The 6-minute walk test (6MWT) is a commonly used method to assess the exercise capacity of people with many health conditions, including persistent pain. However, it is conventionally performed with in-person supervision in a hospital or clinic, therefore requiring staff resources. It may also be difficult when in-person supervision is unavailable, such as during the COVID-19 pandemic, or when the person is geographically remote. A potential solution to these issues could be to use GPS to measure walking distance.

Objective: The primary aim of this study was to assess the validity of a GPS-based smartphone app to measure walking distance as an alternative to the conventional 6MWT in a population with persistent pain. The secondary aim of this study was to estimate the difference between the pain evoked by the 2 test methods.

Methods: People with persistent pain (N=36) were recruited to complete a conventional 6MWT on a 30-m shuttle track and a 6MWT assessed by a smartphone app using GPS, performed on outdoor walking circuits. Tests were performed in random order, separated by a 15-minute rest. The 95% limits of agreement were calculated using the Bland-Altman method, with a specified maximum allowable difference of 100 m. Pain was assessed using an 11-point numerical rating scale before and after each walk test.

Results: The mean 6-minute walk distance measured by the GPS-based smartphone app was 13.2 (SD 46; 95% CI -2.7 to 29.1) m higher than that assessed in the conventional manner. The 95% limits of agreement were 103.9 (95% CI 87.4-134.1) m and -77.6 (95% CI -107.7 to -61) m, which exceeded the maximum allowable difference. Pain increased in the conventional walk test by 1.1 (SD 1.0) points, whereas pain increased in the app test by 0.8 (SD 1.4) points.

Conclusions: In individuals with persistent pain, the 2 methods of assessing the 6MWT may not be interchangeable due to limited validity. Potential reasons for the differences between the 2 methods might be attributed to the variation in track layout (shuttle track vs continuous circuit); poor GPS accuracy; deviations from the 30-m shuttle track; human variability in walking speed; and the potential impact of a first test on the second test due to fatigue, pain provocation, or a learning effect. Future research is needed to improve the accuracy of the GPS-based approach. Despite its limitations, the GPS-based 6MWT may still have value as a tool for remote monitoring that could allow individuals with persistent pain to self-administer frequent assessments of their functional capacity in their home environment.

Keywords: GPS; chronic pain; exercise test; mobile apps; mobile phone; pain.

©Joshua Simmich, Nicole Emma Andrews, Andrew Claus, Megan Murdoch, Trevor Glen Russell. Originally published in JMIR Formative Research (https://formative.jmir.org), 18.03.2024.