PMID- 33788928
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20221110
IS  - 1938-162X (Electronic)
IS  - 1062-6050 (Print)
IS  - 1062-6050 (Linking)
VI  - 56
IP  - 4
DP  - 2021 Apr 1
TI  - Reliability of 3 Urine Specific Gravity Meters for Measuring Brix and Urine 
      Solutions at Different Temperatures.
PG  - 389-395
LID - 10.4085/1062-6050-0142.20 [doi]
AB  - CONTEXT: Urine specific gravity (USG) should be measured at room temperature 
      (20 degrees C), but the temperature of the sample is not always considered. OBJECTIVE: To 
      evaluate the effect of sample temperature on the measurement accuracy of a 
      digital refractometer (DIG), manual optical refractometer (MAN), and hydrometer 
      (HYD). DESIGN: Descriptive laboratory study. MAIN OUTCOME MEASURE(S): Urine 
      specific gravity. RESULTS: Experiment 1 (24 Brix ( degrees Bx) samples) showed that 
      measurements via the DIG and MAN did not differ from the reference, but HYD 
      provided lower or inconsistent values compared with  degrees Bx and was highly correlated 
      with  degrees Bx solutions (r, > = 0.89). The overall diagnostic ability of elevated USG 
      cut-off values (>/=1.020, >/=1.025, >/=1.030) was high for all tools (area under the 
      curve >0.92). Misclassification of samples increased from 0 to 2 at 1.020 to 1 to 
      3 samples at cutoffs of 1.025 and 1.030 USG. Bland-Altman analysis showed that 
      the DIG 5 degrees C underreported slightly without reporting bias (r = -0.344, P = .13); 
      all other plots for the DIG, MAN, and HYD showed considerably larger 
      underreporting at higher concentrations (r = -0.21 to -0.97 with P >.02) at all 
      temperatures. The outcomes of experiment 2 (33 fresh urine samples) using DIG 
      20 degrees C as the standard demonstrated only negligible differences between the DIG and 
      MAN at all temperatures but larger differences using the HYD. CONCLUSIONS: All 
      tools showed reporting bias compared with the  degrees Bx solutions, which can affect the 
      classification of low and high urine concentration at higher USG cutoff values, 
      especially with a sample temperature of 37 degrees C.
CI  - (c) by the National Athletic Trainers' Association, Inc.
FAU - Wardenaar, Floris
AU  - Wardenaar F
AD  - College of Health Solutions, Arizona State University, Phoenix.
FAU - Ortega-Santos, Carmen P
AU  - Ortega-Santos CP
AD  - College of Health Solutions, Arizona State University, Phoenix.
FAU - Vento, Kaila
AU  - Vento K
AD  - College of Health Solutions, Arizona State University, Phoenix.
FAU - Olzinski, Stephanie
AU  - Olzinski S
AD  - College of Health Solutions, Arizona State University, Phoenix.
FAU - Olig, Jason
AU  - Olig J
AD  - College of Health Solutions, Arizona State University, Phoenix.
FAU - Kavouras, Stavros
AU  - Kavouras S
AD  - College of Health Solutions, Arizona State University, Phoenix.
FAU - Johnston, Carol
AU  - Johnston C
AD  - College of Health Solutions, Arizona State University, Phoenix.
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Athl Train
JT  - Journal of athletic training
JID - 9301647
SB  - IM
PMC - PMC8063665
OTO - NOTNLM
OT  - accuracy
OT  - hydration status
OT  - validation
EDAT- 2021/04/01 06:00
MHDA- 2021/04/01 06:01
PMCR- 2022/04/01
CRDT- 2021/03/31 17:22
PHST- 2021/04/01 06:00 [pubmed]
PHST- 2021/04/01 06:01 [medline]
PHST- 2021/03/31 17:22 [entrez]
PHST- 2022/04/01 00:00 [pmc-release]
AID - 463248 [pii]
AID - 10.4085/1062-6050-0142.20 [doi]
PST - ppublish
SO  - J Athl Train. 2021 Apr 1;56(4):389-395. doi: 10.4085/1062-6050-0142.20.