Table 1.
Bivariate relationships between total fluid intake (TFI), 24 h urine volume (Uvol), and osmolality (24 h UOsm).
| Reference | Description | Criterion value | UOsm cutoff value derived from ROC analyses | Sensitivity | Specificity |
|---|---|---|---|---|---|
| EFSA [1] | Dietary reference value for total fluid intake (estimated to be 80% of total water intake) | TFI ≥ 2.0 L·d−1 (men) or ≥ 1.6 L·d−1 (women) |
544 mOsm·kg−1 | 0.86 | 0.80 |
|
| |||||
| Curhan et al. [4] | Multivariate-adjusted odds-ratio (OR) for kidney stones in women with higher TFI | TFI ≥ 1850 mL·d−1 | 525 mOsm·kg−1 | 0.95 | 0.77 |
|
| |||||
| Borghi et al. [23] | In recurrent stone formers, increasing 24 h UVol resulted in a 50% lower stone recurrence rate over 5 years | 24 h UVol ≥ 2.0 L·d−1 | 448 mOsm·kg−1 | 0.98 | 0.82 |