. Author manuscript; available in PMC: 2015 Oct 1.

Published in final edited form as: Kidney Int. 2014 Sep 24;87(4):800–806. doi: 10.1038/ki.2014.323

Table 2.

Duration of CKD and estimated GFR by performance on EF tasks.

EF Measure^a	Performance Groupings	N^b	Measure of CKD Severity
			Duration of CKD (years)			eGFR (ml/min\|1.73m²)

			Median	IQR	p-value^c	Median	IQR	p-value^c
D-KEFS Total Achievement	≤5.5	27	9.4	[5.5, 12.0]	0.109	38.9	[28.5, 56.6]	0.920
D-KEFS Total Achievement	>5.5	261	10.5	[7.3, 14.2]	0.109	42.6	[31.8, 52.0]	0.920

Digit Span Backward	≤5.5	40	9.5	[6.5, 12.4]	0.934	46.4	[35.0, 56.9]	0.318
Digit Span Backward	>5.5	273	9.6	[6.4, 12.8]	0.934	42.7	[30.9, 52.9]	0.318

CPT-II Errors of Commission	≥65	39	11.4	[8.5, 15.2]	0.004	39.3	[32.3, 50.7]	0.623
CPT-II Errors of Commission	<65	264	9.3	[6.2, 12.6]	0.004	43.3	[31.5, 5, 3.7]	0.623

CPT-II Hit Reaction Time	≥65	24	7.5	[5.6, 11.1]	0.107	46.0	[34.1, 61.1]	0.165
CPT-II Hit Reaction Time	<65	280	9.7	[6.4, 13.2]	0.107	42.7	[31.0, 52.1]	0.165

CPT-II Variability	≥65	40	9.8	[6.2, 14.6]	0.940	43.3	[31.8, 52.5]	0.949
CPT-II Variability	<65	265	9.6	[6.4, 12.8]	0.940	39.6	[30.8, 57.6]	0.949

Any of the five	Poor	119	9.9	[6.3, 13.0]	0.941	42.4	[32.8, 54.3]	0.259
Any of the five	Not poor	221	9.6	[6.4, 13.0]	0.941	42.6	[30.3, 51.6]	0.259

Composite of the five	Poor	44	8.9	[6.6, 11.4]	0.277	42.3	[32.6, 56.6]	0.692
Composite of the five	Not poor	296	9.8	[6.4, 13.2]	0.277	42.6	[31.0, 53.1]	0.692

Poor performance on any test of EF is defined as a score ≥ 1.5 SD below the age-adjusted, normal population. On DKEFS and Digit Span Backward, poor performance corresponds to a scaled score ≤ 5.5; on CPT measures, poor performance corresponds to a T score of ≥65.

Differences in numbers are due to missing data for each test.

p-values compare CKD severity measure in poor vs. not poor performing groups by Wilcoxon rank-sum test.