Night Screen Time is Associated with Cognitive Function in Healthy Young Adults: A Cross-Sectional Study

Figures & data

Table 1 Sociodemographic Information of the Participants (n=139)

Variables	Mean ± SD
Age (years)	21.55 ± 2.84
Height (cm)	168.15 ± 9.63
Weight (Kg)	71.63 ± 18.52
BMI (Kg/m^2)	25.08 ± 4.93
Sex	Frequency
Men	63
Women	76
Educational level	Frequency
Bachelor’s level	120
Master’s level	19
Nationality	Frequency
Arabs (non-Emiratis)	114
Emirate	7
Asians	9
Africans	9

Abbreviation: BMI, Body Mass Index.

Table 2 Total Day and Night Screen Time Utilizing Different Types of Screens

Variables	Day Screen Time (Mean ± SD)	Night Screen Time (Mean ± SD)
T.V (minutes)	36.6 ± 62.7	28.5 ± 53.2
T.V-connected devices (minutes)	28.4 ± 73.4	23.0 ± 72.0
Laptop/ computer (minutes)	265.7 ± 245.1	147.5 ± 156.4
Smartphone (minutes)	91.0 ± 183.9	223.5 ± 125.3
Tablet (minutes)	78.9 ± 152.1	42.2 ± 86.2
Total	506.7 ± 319.2	464.6 ± 256.1

Abbreviations: SD, standard deviation; T.V, television.

Table 3 A Summary of Cognitive Function Test Scores

Variables	Men (Mean Rank)	Women (Mean Rank)	Total (Mean ± SD)
PASAT	(42.94)	(37.87)	40.2 ± 9.56
MoCA - Total	(26.11)	(26.28)	26.20 ± 2.14
SDMT-Correct	(56.37)	(59.43)	58.04 ± 10.08
SDMT- Time	(2.89)	(2.62)	2.74 ± 0.83

Abbreviation: SD, standard deviation.

Table 4 The Subcategories of MoCA Cognitive Function Tested in Men and Women

Variables	Men (Mean Rank)	Women (Mean Rank)	Total (Mean ± SD)
MoCA- Visuospatial /Executive function	4.67	4.89	4.79 ± 0.53
MoCA- Naming	3.00	2.97	2.99 ± 0.24
MoCA- Attention	5.06	4.82	4.93 ± 1.02
MoCA- language	1.27	1.59	1.45 ± 1.05
MoCA- Abstraction	1.71	1.79	1.76 ± 0.43
MoCA- Delayed recall	4.43	4.24	4.32 ± 0.97
MoCA- Orientation	5.97	5.97	5.97 ± 0.17

Abbreviation: SD, standard deviation.

Table 5 Variables Associated with PASAT

Variable	β Coefficient	95% CI	p-value	Multicollinearity Tests (VIF)	R^2	Adjusted R^2
Constant	42.28	(28.32, 54.76)	<0.001		0.29%	0.26%
Age	0.082	(−0.473, 0.638)	0.770	1.301
Sex	−3.631	(−6.523, −0.739)	0.014	1.086
Education	4.662	(0.068, 9.256)	0.047	1.305
NST	−0.016	(−0.022, −0.010)	<0.001	1.259
DST	0.000	(−0.005, 0.005)	0.929	1.237

Notes: Values in bold indicate significant difference.

Abbreviations: DST, screen time day; NST, night screen time; VIF, variation inflation factors.

Table 6 Variables Associated with MoCA-Total

Variable	β Coefficient	95% CI	p-value	Multicollinearity Tests (VIF)	R^2	Adjusted R^2
Constant	27.285	(24.338, 30.232)	<0.001		0.064%	0.29%
Age	−0.077	(−0.219, 0.065)	0.287	1.301
Sex	0.216	(−0.525, 0.957)	0.566	1.086
Education	1.014	(−0.163, 2.191)	0.091	1.305
NST	−0.002	(−0.003, 0.000)	0.035	1.259
DST	0.000	(−0.001, 0.001)	0.787	1.237

Notes: Values in bold indicate significant difference.

Abbreviations: DST, Screen Time Day; NST, Night Screen Time; VIF, variation inflation factors.

Table 7 Variables Associated with MoCA-Attention

Variable	β Coefficient	95% CI	p-value	Multicollinearity Tests (VIF)	R^2	Adjusted R^2
Constant	5.846	(4.449, 7.242)	<0.001		0.072%	0.037%
Age	−0.039	(−0.106, 0.029)	0.260	1.301
Sex	−0.227	(−0.578, 0.125)	0.204	1.086
Education	0.394	(−0.163, 0.952)	0.164	1.305
NST	−0.001	(−0.001, 0.000)	0.061	1.259
DST	0.000	(−0.001, 0.000)	0.586	1.237

Abbreviations: DST, Screen Time Day; NST, Night Screen Time; VIF, variation inflation factors.

Table 8 Variables Associated with SDMT

Variable	β Coefficient	95% CI	p-value	Multicollinearity Tests (VIF)	R^2	Adjusted R^2
Constant	60.613	(46.619, 74.606)	<0.001		0.048%	0.012%
Age	−0.192	(−0.868, 0.485)	0.576	1.301
Sex	3.257	(−0.262, 6.776)	0.069	1.086
Education	2.349	(−3.240, 7.939)	0.407	1.305
NST	−0.004	(−.012, 0.003)	0.263	1.259
DST	−0.002	(−0.008, 0.004)	0.532	1.237

Abbreviations: DST, Screen Time Day; NST, Night Screen Time; VIF, variation inflation factors.

Data Sharing Statement

The datasets used in the study are available from the corresponding author on reasonable request.