Table 1 Demographic characteristics of school students, stratified by sex and grade

Median age (years)

15

15

15

−1.910

0.056*

11.00

13.00

16.00

6159.783

0.000*

Sex (Male/Female)

–

–

–

–

–

611/603

1420/1379

1661/2095

32.234

0.000*

Grade (Primary school/Junior high school/Senior high school)

1214/2799/3756

160/451/1420/1661

148/455/1379/2095

32.324

0.000*

–

–

–

–

–

Family structure

50.179

0.000*

384.706

0.000*

 Single parent

794

346

448

72

252

470

 Two parents

2608

1339

1269

160

1064

1384

 Three-generation

2762

1350

1412

601

952

1209

 Other

1605

657

948

381

531

693

Occupation of parents

34.448

0.000*

781.740

0.000*

 Medical staff

160

86

74

7

108

45

 Police

58

31

27

0

40

18

 Civil servant

287

151

136

7

164

116

 Teacher

195

102

93

12

114

69

 Freelancer

1838

906

932

270

637

931

 Farmer

1073

477

596

349

185

539

 Researcher

12

8

4

0

8

4

 Worker

1575

677

898

299

360

916

 Self-employed

1586

797

789

166

761

659

 Others

985

457

528

104

422

459

Family members

 Infected (Yes/No)

165/1604

70/3622

95/3982

1.757

0.185

9/1205

56/2743

100/3656

16.607

0.000*

 Doctor (Yes/No)

272/7497

145/3547

127/3950

3.785

0.052

14/1200

166/2633

92/3664

81.008

0.000*

 Frontline worker (Yes/No)

111/7658

51/3641

60/4017

0.112

0.738

18/1196

66/2733

27/3729

30.627

0.000*

Respondent diagnosed with COVID-19

24/7745

13/3679

11/4066

0.426

0.514

6/1208

4/2795

14/3742

4.355

0.113

Respondent had contact with suspected COVID-19 patient (Yes/No)

27/7742

16/3676

11/4066

1.497

0.221

6/1208

4/2795

17/3739

5.336

0.069*

Respondent received COVID-19 therapy (Yes/No)

157/7612

72/3620

85/3992

0.178

0.673

19/1195

34/2765

104/3652

21.075

0.000*