Mobile phone use habits and risk cognition of students
In this study, 100% of the participants used mobile phones frequently. The descending order of mobile phone usage was 95.02% for studying, 93.94% for entertainment, 64.12% for obtaining information, 29.73% for work, and 15.95% for other purposes. Of the respondents, 89.87% and 72.84% used mobile phones in sitting and lying positions, respectively. A total of 62.96% and 33.47% of the participants had a distance between their eyes and the mobile phone screen of 10ཞ30 cm and 31ཞ50 cm, respectively. The descending order of the survey respondents’ perceptions of physical damage caused by mobile phone use is ocular (99.34%), cervical spine (95.27%), sleep (86.38%) and mental and mental state (71.26%). More than 50% (84.55%, 82.72%, 61.05% and 51.66%) of the participants obtained information about the hazardous aspects of mobile phone use through mobile phone information, Internet media, reading books and family, respectively (Table S1).
Differences in sleep quality before and during the COVID-19 period
Table 1 shows the distribution and differences in different sleep quality levels of the participants between before and during the COVID-19 period. The descending order of the number of cases and percentage is 736 (61.13%) for good sleep quality, 375 (31.15%) for general sleep quality and 93 (7.72%) for poor sleep quality before the COVID-19 period and 761 (63.21%) for good sleep quality, 307 (25.50%) for general sleep quality and 136 (11.30%) for poor sleep quality during the COVID-19 period. There were significant differences of general sleep quality group (p = 0.013) and the poor sleep quality group (p = 0.037) between before and during the COVID-19 period.
Table 1 Difference of equal PSQI quality of students between before and during COVID-19
Quality of sleep
|
Period
|
Number of cases(n)
|
Percentage (%)
|
PSQI score (M±SD)
|
Z
|
P
|
Good (PSQI ≤ 4)
|
Before
|
736
|
61.13
|
2.26 ± 1.31
|
-1.179
|
0.239
|
Good (PSQI ≤ 4)
|
During
|
761
|
63.21
|
2.18 ± 1.31
|
General (5 ≤ PSQI ≤7 )
|
Before
|
375
|
31.15
|
5.93 ± 0.85
|
-2.484
|
0.013
|
General (5 ≤ PSQI ≤7 )
|
During
|
307
|
25.50
|
5.76 ± 0.78
|
Poor (PSQI ≥ 8)
|
Before
|
93
|
7.72
|
9.06 ± 1.55
|
-2.085
|
0.037
|
Poor (PSQI ≥ 8)
|
During
|
136
|
11.30
|
9.55 ± 1.90
|
Note: PSQI – Pittsburgh Sleep Quality Index; M ± SD – mean ± standard deviation;
Before – before COVID-19 period; During – during COVID-19 period.
As shown in Table 2, there were significant differences in the PSQI scores of the participants between before COVID-19 and during COVID-19 with respect to dimensions other than sleep quality. Sleep efficiency (p = 0.017) and hypnotic drugs (P = 0.045), and the sleep latency, sleep persistence, sleep symptoms and sleep dysfunction between the two groups were statistically significant (P < 0.001).
Table 2 Difference of PSQI factors scores of students between before and during COVID-19
Species
|
Factor score (M±SD)
|
t
|
p
|
Before
|
During
|
Sleep quality
|
0.73 ± 0.70
|
0.76 ± 0.74
|
-1.813
|
0.070
|
Sleep latency
|
0.77 ± 0.70
|
0.87 ± 0.86
|
-5.322
|
< 0.001
|
Sleep persistence
|
0.43 ± 0.69
|
0.32 ± 0.64
|
5.153
|
< 0.001
|
Sleep efficiency
|
0.36 ± 0.72
|
0.31 ± 0.68
|
2.386
|
0.017
|
Sleep symptoms
|
0.62 ± 0.58
|
0.56 ± 0.59
|
4.517
|
< 0.001
|
Hypnotic drugs
|
0.04 ± 0.28
|
0.03 ± 0.24
|
2.002
|
0.045
|
Diurnal dysfunction
|
0.97 ± 0.90
|
1.07 ± 0.95
|
-5.411
|
< 0.001
|
Note: PSQI – Pittsburgh Sleep Quality Index; M ± SD – mean ± standard deviation;
Before – before COVID-19 period; During – during COVID-19 period.
Differences in PSQI scores among students before and during the COVID-19 period
As shown in Table 3, 63.95% of the participants stated that the benefits outweighed the disadvantages of mobile phone use; this number was obviously higher than the percentage of the other two groups (18.52% for pros༜cons group and 17.53% for pros = cons group). The descending percentages were 43.11%, 24.34%, 23.75%, 5.32% and 3.49% of the participants who sometimes, rarely, often, always and never took a break during mobile phone use, respectively. The descending percentages were 37.71%, 31.98%, 17.28%, 8.89% and 4.15% of the participants who sometimes, rarely, often, never and always increased the distance between the screen and their eyes, respectively.
Table 3
Differ of PSQI scores with different mobile phone using risk cognitive between before and during COVID-19
|
Number of cases(n)
|
Percentage (%)
|
PSQI score (M ± SD)
|
t
|
P
|
Factors
|
Before
|
During
|
Pros and cons
|
|
|
|
|
Pros ༞ cons
|
770
|
63.95
|
3.83 ± 2.518
|
3.74 ± 2.779
|
1.129
|
0.259
|
Pros ༜ cons
|
223
|
18.52
|
4.28 ± 2.376
|
4.51 ± 2.785
|
-1.634
|
0.104
|
Pros = cons
|
211
|
17.53
|
3.93 ± 2.744
|
3.99 ± 2.974
|
-0.385
|
0.701
|
Will I take a break during using time?
|
|
|
|
|
Never
|
42
|
3.49
|
3.79 ± 3.51
|
4.79 ± 3.854
|
-3.183
|
0.003
|
Rarely
|
293
|
24.34
|
4.42 ± 2.515
|
4.47 ± 2.818
|
-0.404
|
0.686
|
Sometimes
|
519
|
43.11
|
3.95 ± 2.35
|
4.02 ± 2.725
|
-0.834
|
0.405
|
Often
|
286
|
23.75
|
3.52 ± 2.629
|
3.28 ± 2.755
|
2.026
|
0.044
|
Always
|
64
|
5.32
|
3.45 ± 2.618
|
3.08 ± 2.503
|
1.79
|
0.078
|
Will subjectively increase the distance between the screen and the eyes?
|
|
|
Never
|
107
|
8.89
|
4.01 ± 2.967
|
4.36 ± 3.435
|
-1.836
|
0.069
|
Rarely
|
385
|
31.98
|
4.22 ± 2.429
|
4.26 ± 2.682
|
-0.373
|
0.709
|
Sometimes
|
454
|
37.71
|
4.05 ± 2.501
|
4.03 ± 2.862
|
0.21
|
0.834
|
Often
|
208
|
17.28
|
3.37 ± 2.491
|
3.22 ± 2.572
|
1.031
|
0.304
|
Always
|
50
|
4.15
|
2.82 ± 2.318
|
2.56 ± 2.331
|
1.113
|
0.271
|
Note: PSQI – Pittsburgh Sleep Quality Index; M ± SD – mean ± standard deviation; |
Before – before COVID-19 period; During – during COVID-19 period. |
The the groups of never and often of “Will I take a break during using time”? (p = 0.003 and 0.044, respectively) (Table 3). There were significant differences in sleep quality among the three mobile phone using risk cognitive groups both before and during the COVID-19 period. (Table S2).
As shown in Table 4, for daily accumulated use time (hours), the percentages are almost the same for the groups = 0 hours and 5 ~ hours. The ༜5 hours, 10 ~ hours and 15 ~ hours groups were significantly different before and during COVID-19. The percentage of participants before COVID-19 in the ༜5 hours group was 2.33 times higher than during the COVID-19 period. Among the 10 ~ hours and 15 ~ hours groups, the percentages during the COVID-19 period were 2.36 and 2.38 times higher than before the COVID-19 period, respectively.
For use time before bed (hours), among the ༜1 and 1 ~ hour groups, the percentages before COVID-19 were 1.31 and 1.16 times higher than during the COVID-19 period, respectively. Among the = 0, 2 ~ and 3 ~ hours groups, the percentages during the COVID-19 period were 1.79, 1.35 and 1.38 times higher than before the COVID-19 period, respectively.
For use time before bed with the lights on (hours), the percentages are almost the same for the group = 0, ༜0.5 and 1 ~ hour groups. The percentages before COVID-19 were 1.24 times higher than during the COVID-19 period.in the 0.5 ~ hour group. Among the 2 ~ hours group, the percentages during the COVID-19 period was 1.24 times higher than before the COVID-19 period, respectively.
For use time before bed with the lights off (hours), the percentages are almost the same for the group = 0. Among the ༜0.5 and 0.5 ~ hour groups, the percentage before COVID-19 was 1.13 and 1.14 times higher for both compared to the COVID-19 period. Among the 1 ~ and 2 ~ hour groups, the percentages during COVID-19 were 1.13 and 1.24 times higher than before the COVID-19 period, respectively.
There were significantly differences in the sample number of differ groups of four different mobile phone use time between before and during the COVID-19 period (Table S3). The groups with ༜5 and 5 ~ hours of daily accumulated use time (hours) (p = 0.02 and 0.023, respectively), 1 ~ hours of use time before bed (hours) (p = 0.04), and ༜0.5 hours of use time before bed with the lights off (hours) (p = 0.026) differed significantly in the PSQI test scores of the participants before and during the COVID-19 period (Table 4). There were significant differences in sleep quality among the three different mobile phone use time of Use time before bed (hours), Use time before bed with the lights on (hours) and Use time before bed with the lights off (hours) both before and during the COVID-19 period, and the the group of Daily accumulated use time (hours) during the COVID-19 period. (Table S4).
Table 4 Differ of PSQI scores with different mobile phone use time between before and during COVID-19
|
Number of cases(n)
|
Percentage (%)
|
PSQI score (M ± SD)
|
Z
|
P
|
Factors
|
Before
|
During
|
Before
|
During
|
Before
|
During
|
Daily accumulated use time (hours)
|
|
|
|
|
|
= 0
|
7
|
12
|
0.58
|
1.00
|
4.14 ± 2.91
|
5.42 ± 3.66
|
-0.641
|
0.522
|
<5
|
468
|
201
|
38.87
|
16.69
|
3.70 ± 2.29
|
3.38 ± 2.63
|
-2.329
|
0.02
|
5 ~
|
562
|
596
|
46.68
|
49.50
|
3.99 ± 2.59
|
3.69 ± 2.66
|
-2.277
|
0.023
|
10 ~
|
125
|
295
|
10.38
|
24.50
|
4.42 ± 3.05
|
4.31 ± 2.89
|
-0.238
|
0.812
|
15 ~
|
42
|
100
|
3.49
|
8.31
|
4.24 ± 2.53
|
5.13 ± 3.37
|
-1.108
|
0.268
|
Use time before bed (hours)
|
|
|
|
|
|
= 0
|
15
|
27
|
1.25
|
2.24
|
3.27 ± 2.60
|
3.30 ± 2.18
|
-0.146
|
0.884
|
<1
|
234
|
179
|
19.44
|
14.87
|
3.50 ± 2.47
|
3.51 ± 2.76
|
-0.322
|
0.747
|
1 ~
|
608
|
524
|
50.50
|
43.52
|
3.86 ± 2.45
|
3.64 ± 2.61
|
-2.055
|
0.04
|
2 ~
|
154
|
208
|
12.79
|
17.28
|
3.99 ± 2.39
|
4.04 ± 2.59
|
-0.119
|
0.905
|
3 ~
|
193
|
266
|
16.03
|
22.09
|
4.68 ± 2.84
|
4.76 ± 3.31
|
-0.378
|
0.705
|
Use time before bed with the lights on (hours)
|
|
|
|
|
= 0
|
42
|
43
|
3.49
|
3.57
|
3.33 ± 2.52
|
3.16 ± 2.18
|
-0.146
|
0.968
|
<0.5
|
144
|
133
|
11.96
|
11.05
|
3.84 ± 2.49
|
3.45 ± 2.52
|
-1.45
|
0.147
|
0.5 ~
|
374
|
302
|
31.06
|
25.08
|
3.67 ± 2.47
|
3.56 ± 2.68
|
-0.994
|
0.32
|
1 ~
|
353
|
364
|
29.32
|
30.23
|
4.02 ± 2.40
|
3.88 ± 2.68
|
-1.217
|
0.224
|
2 ~
|
291
|
362
|
24.17
|
30.07
|
4.28 ± 2.77
|
4.55 ± 3.15
|
-0.404
|
0.686
|
Use time before bed with the lights off (hours)
|
|
|
|
|
= 0
|
170
|
185
|
14.12
|
15.37
|
3.26 ± 2.39
|
3.43 ± 2.63
|
-0.325
|
0.745
|
<0.5
|
337
|
299
|
27.99
|
24.83
|
3.73 ± 2.36
|
3.4 ± 2.55
|
-2.23
|
0.026
|
0.5 ~
|
339
|
297
|
28.16
|
24.67
|
3.84 ± 2.44
|
3.7 ± 2.62
|
-0.987
|
0.324
|
1 ~
|
188
|
213
|
15.61
|
17.69
|
4.26 ± 2.47
|
4.15 ± 2.66
|
-0.828
|
0.408
|
2 ~
|
170
|
210
|
14.12
|
17.44
|
4.8 ± 3.00
|
5.22 ± 3.37
|
-0.971
|
0.332
|
Note: PSQI – Pittsburgh Sleep Quality Index; M ± SD – mean ± standard deviation;
Before – before COVID-19 period; During – during COVID-19 period.
Generalized linear regression analysis of different influencing factors and sleep quality
As shown in Tables 5, with regard to the pros and cons (p = 0.007) of mobile phone use, how often breaks were taken during use time (p = 0.003) and Will subjectively increase the distance between the screen and the eyes? (p = 0.003)were significantly correlated with sleep quality. Pros༜cons and Pros = cons of mobile phone using risk cognitive was negative factors for sleep quality. More frequent of take breaks during mobile phone use time and subjectively increase the distance between the screen and the eyes were protective factors for sleep quality.
Table 5
Generalized linear regression analysis of different mobile phone using risk cognitive and sleep quality during COVID-19
Factors
|
B
|
SE
|
Wald
|
df
|
P
|
OR (95% CI)
|
Pros and cons
|
9.787
|
2
|
0.007
|
|
Pros ༞consa
|
|
|
|
|
|
|
Pros ༜ cons
|
0.659
|
0.211
|
9.755
|
1
|
0.002
|
1.933(1.278,2.923)
|
Pros = cons
|
0.188
|
0.2148
|
0.762
|
1
|
0.383
|
1.206(0.792,1.838)
|
How often take a break during using time?
|
16.066
|
4
|
0.003
|
|
Nevera
|
|
|
|
|
|
|
Rarely
|
-0.256
|
0.4714
|
0.295
|
1
|
0.587
|
0.774(0.307,1.95)
|
Sometimes
|
-0.615
|
0.46
|
1.787
|
1
|
0.181
|
0.541(0.219,1.332)
|
Often
|
-1.131
|
0.4761
|
5.639
|
1
|
0.018
|
0.323(0.127,0.821)
|
Always
|
-1.09
|
0.577
|
3.568
|
1
|
0.059
|
0.336(0.109,1.042)
|
Will subjectively increase the distance between the screen and the eyes?
|
16.068
|
4
|
0.003
|
|
Nevera
|
|
|
|
|
|
|
Rarely
|
-0.028
|
0.3127
|
0.008
|
1
|
0.929
|
0.973(0.527,1.795)
|
Sometimes
|
-0.123
|
0.3084
|
0.158
|
1
|
0.691
|
0.885(0.483,1.619)
|
Often
|
-0.763
|
0.3434
|
4.937
|
1
|
0.026
|
0.466(0.238,0.914)
|
Always
|
-1.292
|
0.5008
|
6.653
|
1
|
0.010
|
0.275(0.103,0.733)
|
Constant
|
4.668
|
0.4576
|
104.074
|
1
|
༜0.001
|
106.504(43.438,261.137)
|
Note: a: control group. |
Table 6 have shown that Daily accumulated use time (hours) (p = 0.003) and use time before bed with the lights off (hours) (p < 0.001) were significantly correlated with sleep quality. The longer the daily accumulated use time and the use time before bed with the lights off, the worse the sleep quality was.
Table 6 Generalized linear regression analysis of different mobile phone use time and sleep quality during COVID-19
Factors
|
B
|
SE
|
Wald
|
df
|
P
|
OR (95% CI)
|
Daily accumulated use time (hours)
|
16.061
|
4
|
0.003
|
|
= 0a
|
|
|
|
|
|
|
<5
|
-2.268
|
0.8255
|
7.545
|
1
|
0.006
|
0.104(0.021,0.522)
|
5 ~
|
-2.079
|
0.8141
|
6.522
|
1
|
0.011
|
0.125(0.025,0.617)
|
10 ~
|
-1.71
|
0.8237
|
4.308
|
1
|
0.038
|
0.181(0.036,0.909)
|
15 ~
|
-1.271
|
0.8592
|
2.187
|
1
|
0.139
|
0.281(0.052,1.512)
|
Use time before bed (hours)
|
1.511
|
4
|
0.825
|
|
= 0a
|
|
|
|
|
|
|
<1
|
0.415
|
0.5955
|
0.485
|
1
|
0.486
|
1.514(0.471,4.865)
|
1 ~
|
0.201
|
0.5786
|
0.121
|
1
|
0.728
|
1.223(0.394,3.802)
|
2 ~
|
0.251
|
0.6041
|
0.172
|
1
|
0.678
|
1.285(0.393,4.199)
|
3 ~
|
0.428
|
0.6112
|
0.489
|
1
|
0.484
|
1.534(0.463,5.081)
|
Use time before bed with the lights on (hours)
|
4.089
|
4
|
0.394
|
|
= 0a
|
|
|
|
|
|
|
<0.5
|
0.623
|
0.5122
|
1.477
|
1
|
0.224
|
1.864(0.683,5.086)
|
0.5 ~
|
0.712
|
0.4783
|
2.219
|
1
|
0.136
|
2.039(0.799,5.206)
|
1 ~
|
0.892
|
0.4756
|
3.52
|
1
|
0.061
|
2.441(0.961,6.2)
|
2 ~
|
0.891
|
0.4891
|
3.322
|
1
|
0.068
|
2.439(0.935,6.361)
|
Use time before bed with the lights off (hours)
|
30.042
|
4
|
<0.001 0
|
|
= 0a
|
|
|
|
|
|
|
<0.5
|
-0.027
|
0.2619
|
0.01
|
1
|
0.919
|
0.974(0.583,1.627)
|
0.5 ~
|
0.297
|
0.2621
|
1.287
|
1
|
0.257
|
1.346(0.805,2.25)
|
1 ~
|
0.598
|
0.2814
|
4.515
|
1
|
0.034
|
1.818(1.047,3.156)
|
2 ~
|
1.41
|
0.3062
|
21.192
|
1
|
<0.001
|
4.095(2.247,7.462)
|
Constant
|
4.37
|
0.9107
|
23.025
|
1
|
<0.001
|
79.029(13.262,470.929)
|
Note: a: control group.