Event- and time-based prospective memory in hemodialysis patients

Figures & data

Table 1. The demographic data and neuropsychological test results for the HD patients and controls.

	Controls (mean ± SD)	HD patients (mean ± SD)	p-Value
Age, years	44.83 ± 13.00	45.55 ± 12.35	0.76
Education, years	13.28 ± 2.15	13.05 ± 1.87	0.61
Male (%)	34 (56.7%)	34 (56.7%)	1.00
Duration of hemodialysis, years		7.3 ± 5.0
Hypertension (%)	23 (38.3%)	47 (78.3%)	<0.001^a
Diabetic (%)	5 (8.3%)	10 (16.7%)	0.17
MMSE	29.10 ± 0.84	28.33 ± 0.77	<0.001^a
DST-Forward digit span	9.00 ± 1.25	8.97 ± 1.33	0.96
DST-Backward digit span	5.23 ± 1.89	4.60 ± 1.54	0.11
RAVLT
Total recall	44.47 ± 5.82	40.03 ± 10.46	<0.001^a
Delayed recall	7.28 ± 2.36	6.87 ± 3.33	0.09
Delayed recognition	6.93 ± 1.49	5.40 ± 1.33	<0.001^a
SCWT
Reaction time (s)
Reading	6.47 ± 1.05	7.47 ± 1.86	<0.001^a
Colors naming	9.07 ± 1.29	11.43 ± 2.34	<0.001^a
Interference	8.78 ± 1.92	10.22 ± 2.91	<0.001^a
Inhibition/switching	14.53 ± 2.90	19.85 ± 4.69	<0.001^a
Error
Reading	0.00 ± 0.00	0.03 ± 0.18	0.16
Colors naming	0.00 ± 0.00	0.10 ± 0.35	0.02
Interference	0.03 ± 0.18	0.08 ± 0.28	0.25
Inhibition/switching	0.08 ± 0.28	0.35 ± 0.63	<0.001^a
VFT (animal)	16.70 ± 3.50	17.68 ± 5.45	0.56
VFT (fruit)	17.47 ± 3.18	15.92 ± 4.56	<0.001^a

^aMann–Whitney U test.

MMSE: Mini-Mental State Examination; DST: the digit span test; RAVLT: Rey Auditory Verbal Learning Test; SCWT: Stroop Color Word Interference Test; VFT: Verbal Fluency Test.

Table 2. Performance of the control group and the HD patients on subitems of the event based prospective memory tasks.

	Controls (mean ± SD)	HD patients (mean ± SD)	p-Value
Prospective memory score	7.85 ± 0.40	7.08 ± 1.43	0.001*
Retrospective memory score	4.75 ± 1.34	3.37 ± 1.47	<0.001*

*Mann-Whitney U test.

Table 3. Performance of the control group and HD patients on subitems of the TBPM tasks.

	Controls (mean ± SD)	HD patients (mean ± SD)	p-Value
Prospective memory score	3.30 ± 1.31	2.26 ± 1.82	<0.001^a
Retrospective memory score	3.23 ± 1.43	2.37 ± 1.54	0.002^a
Number of clock checking responses	32.33 ± 2.32	27.88 ± 3.95	<0.001^a

^aMann–Whitney U test.

Figure 1. Participant flow diagram.

Figure 2. Mean number of clock checking responses in the control group and the HD patients group in each one minute period during the EBPM task.

Table 4. Correlation analyses for the EBPM and TBPM score with demographics, clinical variables and neuropsychological parameters in HD patients.

	PM tasks
	EBPM		TBPM
	r	p	r	p
Age	−0.0182	0.163	−0.038	0.771
Education	0.087	0.508	−0.123	0.348
Duration of hemodialysis	0.037	0.779	0.323	0.012*
MMSE	0.174	0.185	0.176	0.178
DST-Forward digit span	0.386	0.002*	0.200	0.125
DST-Backward digit span	−0.138	0.292	0.376	0.003*
RAVLT-Total recall	0.331	0.010*	0.238	0.067
RAVLT-Delayed recall	0.125	0.342	0.263	0.042*
RAVLT-Delayed recognition	0.124	0.347	0.325	0.011*
SCWT-Reading-Time	−0.352	0.006*	−0.057	0.664
SCWT-Colors naming-Time	−0.340	0.008*	0.028	0.831
SCWT-Interference-Time	−0.143	0.276	0.072	0.585
SCWT-Inhibition/switching-Time	−0.251	0.054	−0.019	0.883
SCWT-Reading-Error	0.120	0.361	0.178	0.173
SCWT-Colors Naming-Error	−0.251	0.053	−0.042	0.750
SCWT-Interference-Error	−0.230	0.077	−0.111	0.397
SCWT-Inhibition/switching-Error	−0.145	0.269	0.123	0.347
VFT (animal)	0.425	0.001*	0.394	0.002*
VFT(fruit)	0.323	0.012*	0.313	0.015*

EBPM: event based prospective memory; TBPM: time based prospective memory; MMSE: Mini-Mental State Examination; DST: the digit span test; RAVLT: Rey Auditory Verbal Learning Test; SCWT: Stroop Color Word Interference Test; VFT: Verbal Fluency Test.

*p value < 0.05.