Table 1

Baseline characteristic across sex

VariablesTotalBoysGirlsP value
n (%)n (%)
Total21 774 (100)10 297 (47.3)11 010 (50.6)
Living arrangement
 With parents16 756 (77.0)7808 (75.8)8604 (78.1)<0.001
 With single parent2017 (9.3)993 (9.6)981 (8.9)
 With other relatives3001 (13.8)1496 (14.5)1425 (12.9)
Economic status
 Above average5784 (26.6)2893 (28.2)2775 (25.3)<0.001
 Average13 293 (61.0)6044 (58.9)6976 (63.6)
 Below average2628 (12.1)1330 (13.0)1223 (11.1)
 Missing69 (0.3)
Parental marriage status
 Harmonious13 279 (61.0)6374 (61.9)6633 (60.2)0.004
 Conflicting7237 (33.2)3373 (32.8)3688 (33.5)
 Separated or divorced1078 (5.0)464 (4.5)602 (5.5)
 Other180 (0.8)86 (0.8)87 (0.8)
Paternal education level
 Low19 215 (88.2)8956 (88.2)9839 (90.5)<0.001
 High2263 (10.4)1196 (11.8)1031 (9.5)
 Missing296 (1.4)
Maternal education level
 Low20 005 (91.9)9360 (92.1)10 212 (93.8)<0.001
 High1509 (6.9)807 (7.9)677 (6.2)
 Missing260 (1.2)
Pocket money (¥)
 0–20017 251 (79.2)8112 (78.8)8750 (79.5)0.183
 200–4002856 (13.2)1356 (13.2)1447 (13.1)
 >4001667 (7.7)829 (8.1)813 (7.4)
Parental smoking
 Father10 820 (49.7)4957 (48.1)5631 (51.1)<0.001
 Mother53 (0.2)18 (0.2)34 (0.3)
 Both120 (0.6)57 (0.6)61 (0.6)
 Neither10 781 (49.5)5265 (51.1)5284 (48.0)
Parental drinking
 Father5256 (24.1)2544 (24.7)2588 (23.5)0.013
 Mother265 (1.2)106 (1.0)155 (1.4)
 Both563 (2.6)256 (2.5)300 (2.7)
 Neither15 690 (72.1)7391 (71.8)7967 (72.4)
Parental NMUPD
 Yes670 (3.1)313 (3.0)336 (3.1)0.959
 No21 104 (96.9)9984 (97.0)10 674 (96.9)
Any kinds of NMUPD
 Yes1381 (6.3)730 (7.1)623 (5.7)<0.001
 No20 393 (93.7)9567 (92.9)10 387 (94.3)
Sedatives
 Yes686 (3.2)334 (3.2)336 (3.1)0.432
 No21 088 (96.8)9963 (96.8)10 674 (96.9)
Opioids
 Yes842 (3.9)476 (4.6)350 (3.2)<0.001
 No20 932 (96.1)9821 (95.4)10 660 (96.8)
Stimulants
 Yes555 (2.5)315 (3.1)228 (2.1)<0.001
 No21 219 (97.5)9982 (96.9)10 782 (97.9)
  • NMUPD, non- medical use of prescription drugs.