Document Type
Article
Publication Date
2024
DOI
10.1371/journal.pone.0313320
Publication Title
PLoS One
Volume
19
Issue
11
Pages
1-9
Abstract
Assessing hydration status outside of laboratories can be challenging given that most hydration measures are invasive, stationary, costly, or have questionable validity. This study investigated the within-day, test-retest reliability, and minimal detectable change (MDC) of the MX3 Hydration Testing System (MX3 Diagnostics), a relatively low cost, noninvasive, and portable method to measure saliva osmolality. Seventy-five adults (44 men, 31 women; 29.6±10.8 yr, 171.1±9.2 cm, 79.1±15.4 kg) presented two saliva samples approximately 3 to 5 minutes apart. Fluid intake was avoided for at least 5 minutes prior to sample collections. For each sample collection, a researcher used the MX3 to tap the tip of a test strip to saliva on a participant's tongue. Intra-class correlation coefficients (ICCs) and MDC were calculated as measures of reliability. Means for the two measurements were 64.3±19.0 mOsm and 65.5±17.9 mOsm (mean difference of -1.2±13.0 mOsm; t = -0.806, p = 0.423). Further analysis with a two-one-sided test procedure revealed equivalence between the two SOSM measurements (p < 0.001 for upper and lower bounds). Within-day repeat measures yielded an ICC of 0.75 and an MDC at the 90% confidence level of 21.3 mOsm. With moderate-to-good reliability, the MX3 appears to be a practical choice for reliably measuring moderate-sized changes (>20 mOsm) in saliva osmolality outside of laboratory constraints.
Rights
© 2024 Winter et al.
This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability
Article states: "All relevant data are within the manuscript and its Supporting Information files."
Original Publication Citation
Winter, I., Burdin, J., & Wilson, P. B. (2024). Reliability and minimal detectable change of the MX3 hydration testing system. PLoS One, 19(11), 1-9, Article e0313320. https://doi.org/10.1371/journal.pone.0313320
Repository Citation
Winter, I., Burdin, J., & Wilson, P. B. (2024). Reliability and minimal detectable change of the MX3 hydration testing system. PLoS One, 19(11), 1-9, Article e0313320. https://doi.org/10.1371/journal.pone.0313320
ORCID
0000-0003-4052-5023 (Wilson)
Supporting Information