Table 3.

Multivariable analysis of the correlates of 24-hour urinary output

Adjusted R-squared of the model = 0.62	β ± SE	P-value
Maximal Uosm	−2.9 ± 0.34	<0.001
Osmolar intake	2.2 ± 0.24	<0.001
Thirst score	−62.54 ± 23.48	0.009
Lithium daily dose	0.5 ± 0.17	0.004
Male sex	−369.25 ± 121.67	0.003
Plasma vasopressin	10.5 ± 4.74	0.03

mGFR, measured glomerular filtration rate; Uosm, urine osmolality.

Variables included in the consecutive models were the following and in the following order: maximal urinary osmolality, mGFR, 24-hour osmolar intake, fasting thirst score, lithium treatment duration, lithium dose, lithium formulation, sex, ionized calcium, extracellular volume, hypertension, plasma vasopressin, age, and body mass index. In the last model remained 3 variables that were not significantly associated with urine output: mGFR, lithium formulation, and extracellular volume (P = 0.5, P = 0.2, and P = 0.9, respectively).