Table 3.

Results of mixed regression models assessing timing (difference between test performance before vs. during dialysis) and learning (difference between 1st and 2nd tests)

Test	Timing β (95% CI) (dialysis effect)	p value	Period β (95% CI) (learning effect)	p value
MMSE	0.09 (−0.62, 0.80)	0.8	−0.28 (−0.99, 0.43)	0.4
Verbal IQ (NAART)	−0.66 (−1.75, 0.43)	0.2	−0.15 (−1.23, 0.94)	0.8
Word List Learning
Delayed Recall	0.15 (−0.43, 0.72)	0.6	−0.91 (−1.48, −0.34)	0.003
Total Recall	−0.23 (−1.60, 1.14)	0.7	−2.91 (−4.29, −1.54)	<0.001
Recognition	0.41 (−0.46, 1.27)	0.4	−0.12 (−0.98, 0.74)	0.8
Blocks Design	0.03 (−1.75, 1.80)	0.9	−1.60 (−3.38, 0.18)	0.08
Digit Span
Digits Forward	−0.24 (−0.77, 0.29)	0.4	0.29 (−0.24, 0.81)	0.3
Digits Backward	0.11 (−0.48, 0.70)	0.7	0.03 (−0.56, 0.62)	0.9
Digit Symbol Substitution	1.89 (−0.67, 4.45)	0.14	−3.27 (−5.83, −0.71)	0.01
Trail Making Tests
Trails A	−1.19 (−8.89, 6.50)	0.8	2.38 (−5.31, 10.08)	0.5
Trails B	−9.77 (−27.91, 8.38)	0.3	1.81 (−16.33, 19.96)	0.8
Mental Alternation	0.80 (−0.96, 2.55)	0.4	−0.46 (−2.22, 1.29)	0.6
COWAT
Animals	0.47 (−1.26, 2.20)	0.6	−0.90 (−2.63, 0.83)	0.3
Supermarket Items	0.92 (−1.38, 3.22)	0.4	0.65 (−1.64, 2.95)	0.6

Period (learning effect) = difference in scores for first time taking test and second time taking test; dialysis effect = difference in scores for testing before and during first hour of dialysis. For all tests, except the Trail Making Tests, a negative β coefficient is consistent with learning, while for the Trail Making Tests a positive β coefficient indicates learning. Similarly, for all tests except the Trail Making Tests, a positive timing β coefficient suggests before dialysis performance is superior to during dialysis, while for the Trail Making Tests, a negative timing β coefficient suggests before dialysis performance is superior to during dialysis.