Table 3.

Effect of CKD stage 4 versus stage 1–2 on cognitive function over time

	Total		History of vascular disease		No history of vascular disease		interaction
	Beta (95%CI)	p-value	Beta (95%CI)	p-value	Beta (95%CI)	p-value	p-value
Stroop-Colour-Word Test	2.26 (0.63–3.88)	0.007	6.52 (3.94–9.10)	< 0.0001	− 0.11 (− 2.21–1.99)	0.919	0.016
Letter-Digit Coding Test	− 0.33(− 0.66–0.00)	0.050	−1.00 (− 1.62 – − 0.37)	0.002	−0.08 (− 0.47–0.32)	0.694	0.115
Picture-Word Learning Test – immediate	0.08 (− 0.06–0.21)	0.274	0.16 (− 0.08–0.40)	0.180	0.03 (−0.13–0.20)	0.695	0.529
Picture-Word Learning Test – delayed	−0.07 (− 0.27–0.13)	0.503	−0.02 (− 0.37–0.34)	0.930	−0.09 (− 0.33–0.15)	0.485	0.123
The Barthel index	−0.01 (− 0.11–0.08)	0.766	0.01 (− 0.16–0.18)	0.940	−0.02 (− 0.13–0.08)	0.642	0.737
Instrumental Activities of Daily Living	0.03 (− 0.09–0.15)	0.622	0.06 (− 0.15–0.28)	0.561	0.01 (− 0.12–0.15)	0.868	0.064

* p-values of differences in cognitive test score changes over time were assessed between CKD stage 4 (eGFR < 30 ml/min/1.73m²) versus CKD stage 1–2 (eGFR > 60 ml/min/1.73m²) using linear mixed models adjusted for prespecified variables including sex, age, educational status, country, statin treatment and multiple other known vascular confounders