Table 2.

Equivalence test of urine osmolality at different time-windows with 24-h urine sample by using 80 mmol kg⁻¹ as bound

Time-window (h)	Mean spot UOsm (mmol kg−1)	Mean absolute difference (spot vs. 24-h UOsm)	N	95 % CI of mean (mmol kg−1)		Equivalence test
				Lower limit	Upper limit	Bound 80 mmol kg−1
0600–1159	766	(+) 80	375	61	100	N
1200–1559	753	(+) 65	461	48	83	N
1600–1959a	757	(+) 62	470	45	78	Y
2000–2359	784	(+) 90	357	73	107	N
Overnight	729	(+) 50	71	10	89	N
First morning	800	(+) 88	414	74	102	N

^aEquivalent to 24-h sample based on 80 mmol kg⁻¹ bound (P < 0.05)

Overnight:2400–0559, first morning: 0600–0959 the next day

Bold values indicates time-window that was identified as equivalent to the 24-h urine sample (P < 0.05)