Table 2 Methodological analyses in saliva lab tests for creatinine, uric acid, and potassium in control group: blind duplicates, site of collection, day-to-day variability, time of collection, and freezing/thawing effect (mean ± SEM)
From: Saliva for assessing creatinine, uric acid, and potassium in nephropathic patients
P | R | |||
|---|---|---|---|---|
Blind duplicates | first duplicate | second duplicate | ||
Creatinine, μmol/L | 11.5 ± 3.9 | 11.7 ± 1.5 | 0.321 | 0.748 § |
Uric acid, μmol/L | 261 ± 166 | 251 ± 145 | 0.187 | 0.993* |
Potassium, mmol/L | 22.2 ± 6.6 | 22.5 ± 5.9 | 0.349 | 0.997* |
Site of collection | right vestibulum | left vestibulum | ||
Creatinine, μmol/L | 11.7 ± 4.1 | 11.4 ± 1.6 | 0.628 | 0.728 § |
Uric acid, μmol/L | 262 ± 74 | 264 ± 65 | 0.865 | 0.991* |
Potassium, mmol/L | 23.2 ± 7.5 | 23.6 ± 5.8 | 0.791 | 0.898* |
Day-to-day variability | first day | second day | ||
Creatinine, μmol/L | 11.5 ± 3.9 | 11.5 ± 2.0 | 0.723 | 0.735 § |
Uric acid, μmol/L | 261 ± 166 | 255 ± 165 | 0.790 | 0.677 § |
Potassium, mmol/L | 22.2 ± 6.6 | 25.4 ± 6.7 | 0.389 | 0.620 § |
Time of collection | standard sample | mid-morning sample | ||
Creatinine, μmol/L | 11.5 ± 3.9 | 9.1 ± 1.5 | 0.038 | 0.765 |
Uric acid, μmol/L | 261 ± 166 | 184 ± 102 | < 0.001 | 0.915 |
Potassium, mmol/L | 22.2 ± 6.6 | 18.7 ± 5.9 | < 0.001 | 0.728 |
Freezing/thawing effects | standard sample | frozen/thawed sample | ||
Creatinine, μmol/L | 11.5 ± 3.9 | 10.5 ± 1.4 | 0.488 | 0.899 |
Uric acid, μmol/L | 261 ± 166 | 216 ± 118 | < 0.001 | 0.818 |
Potassium, mmol/L | 22.2 ± 6.6 | 21.4 ± 5.7 | 0.389 | 0.829 |