Table 3. Time within therapeutic range and INR variability within the entire population of 724 patients with atrial fibrillation.

		No CKD	Moderate CKD	P-value comparison	Severe CKD	P-value comparison	P-value comparison with
		eGFR>60 ml/min	eGFR 30-60 ml/min	with no CKD patients	eGFR<30 ml/min	with no CKD patients	moderate CKD patients
Time spend within therapeutic range, %
First six weeks of VKA therapy		39.4(13.2–73.5)	49.7(24.1–81.3)	0.01	44.1(26.4–77.9)	0.10	0.60
First eighteen weeks of VKA therapy		57.9(29.8–79.3)	65.5(42.1–83.9)	0.01	60.7(39.4–80.6)	0.37	0.19
First twenty-six weeks of VKA therapy		61.5(38.7–79.8)	67.1(46.7–82.4)	0.02	64.7(41.5–75.6)	0.92	0.07
Entire treatment period		67.0(43.1–81.1)	75.1(57.8–82.9)	<0.01	70.3(49.2–81.1)	0.41	0.10
Time under target range (entire treatment), %		8.7(2.6–35.5)	6.2(2.1–13.0)	<0.001	5.5(2.3–12.9)	0.001	0.77
Time above target range (entire treatment), %		11.7(3.9–21.2)	15.2(9.8–24.0)	<0.001	20.8(11.7–32.7)	<0.001	<0.01
INR variability (2.5-97.5 percentiles)
First six weeks of VKA therapy		0.5(0.1–1.6)	0.6(0.2–1.6)	0.10	0.7(0.4–2.3)	0.001	0.03
First eighteen weeks of VKA therapy		0.4(0.2–1.3)	0.6(0.2–1.5)	0.08	0.8(0.4–1.8)	<0.001	0.01
First twenty-six weeks of VKA therapy		0.5(0.3–1.2)	0.7(0.4–1.2)	0.24	0.8(0.4–1.8)	<0.001	<0.01
Entire treatment period		0.5(0.3–1.2)	0.7 (0.4–1.2)	0.03	0.9(0.5–1.8)	<0.001	<0.01

Data are presented as median, (Interquartile range), P-values were computed using Mann-Whitney test, after proof of significant differences between groups using a Kruskal-Wallis test.

CKD  =  chronic kidney disease, VKA  =  vitamin K-antagonists, eGFR  =  estimated glomerular filtration rate, INR  =  international normalized ratio.