Persistent cognitive slowing in post-COVID patients: longitudinal study over 6 months

Table 2 Comparison of age-normed scores of PCS patients and healthy control participants in the different test battery tasks and domains at baseline

Cognitive measures	PCS patients (n = 88)	Healthy control participants (n = 50)	Comparison between groups
TAP—T-scores (M = 50, SD = 10)	Mdn (IQR) Percentage below > 1.5 SD from the norm’s mean	Mdn (IQR) Percentage below > 1.5 SD from the norm’s mean	p	r
RT tonic alertness	34.00 (8.00) 53.41%	43.50 (11.00) 12.00%	< 0.001	0.51
RT phasic alertness	33.00 (12.00) 59.09%	42.00 (10.00) 8.00%	< 0.001	0.50
RT divided attention (auditory)	35.00 (13.00) 48.86%	45.60 (15.00) 14.00%	< 0.001	0.38
RT divided attention (visual)	44.00 (15.00) 18.18%	51.50 (12.00) 8.00%	0.004	0.25
RT inhibition	41.50 (17.00) 27.27%	49.00 (12.00) 8.00%	0.002	0.29
Errors divided attention	49.00 (15.00) 1.14%	49.00 (18.00) 14.00%	0.345
Errors inhibition	53.00 (7.00) 0.00%	53.00 (1.00) 0.00%	0.020	0.20
S-NAB—standard scores (M = 100, SD = 15)	M (SD) Percentage below > 1.5 SD from the norm’s mean	M (SD) Percentage below > 1.5 SD from the norm’s mean	p	d
Attention	82.52 (14.41) 36.6%	99.16 (14.10) 2.00%	< 0.001	1.17
Language	101.65 (17.34) 6.82%	107.06 (11.31) 0.00%	0.053
Memory	104.09 (14.34) 2.27%	110.66 (12.63) 0.00%	0.010	0.48
Perception	94.72 (13.77) 9.09%	103.32 (12.57) 0.00%	< 0.001	0.65
Executive functions	87.61 (15.50) 28.41%	101.70 (12.79) 4.00%	< 0.001	0.97

Mdn and IQR are reported for Wilcoxon rank-sum tests, M and SD for t tests. FDR-adjusted p values. Effect sizes (Cohen’s d for t tests, r for Wilcoxon rank-sum tests) were only reported for significant tests with d ≥ 0.2; r ≥ 0.1 indicating small, d ≥ 0.5; r ≥ 0.3 indicating moderate, and d ≥ 0.8; r ≥ 0.5 indicating large effects
TAP Test for attentional performance, S-NAB Neuropsychological assessment battery screening module