Validity of Urine Color Scoring Using Different Light Conditions and Scoring Techniques to Assess Urine Concentration

Floris Wardenaar, Scott Armistead, Kayla Boeckman, Brooke Butterick, Darya Youssefi, Daniel Thompsett, Kaila Vento

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Context: Urine color (Uc) is used to asses urine concentration when laboratory techniques are not feasible. Objective: To compare the accuracy of Uc scoring using 4 light conditions and 2 scoring techniques with a 7-color Uc chart. Additionally, to assess the results' generalizability, a subsample was compared with scores obtained from fresh samples. Design: Descriptive laboratory study. Samples: A total of 178 previously frozen urine samples were scored, and 78 samples were compared with their own fresh outcomes. Main Outcome Measure(s): Urine color and accuracy for classifying urine samples were calculated using receiver operating characteristics analysis, allowing us to compare the diagnostic capacity against a 1.020 urine specific gravity cutoff and defining optimal Uc cutoff value. Results: Urine color was different among light conditions (P<.01), with the highest accuracy (80.3%) of correct classifications of low or high urine concentrations occurring at the brightest light condition. Lower light intensity scored 1.5 to 2 shades darker on the 7-color Uc scale than bright conditions (P<.001), but no further practical differences in accuracy occurred between scoring techniques. Frozen was 0.5 to 1 shade darker than freshly measured Uc (P<.004), but the values were moderately correlated (r = 0.64). A Bland-Altman plot showed that reporting bias mainly affected darker Uc without affecting the diagnostic ability of the method. Conclusions: Urine color scoring, accuracy, and Uc cutoff values were affected by lighting condition but not by scoring technique, with greater accuracy and a 1-shade-lower Uc cutoff value at the brightest light (ie, light-emitting diode flashlight).

Original languageEnglish (US)
Pages (from-to)191-198
Number of pages8
JournalJournal of Athletic Training
Issue number2
StatePublished - Feb 2022


  • assessment of hydration status
  • fluid intake monitoring
  • hydration education
  • hydration status

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation


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