Background
Methods
Context and data source
Study design and sampling
Measures
Outcome variables
Exposure variables
Statistical analyses
Results
Participant characteristics
Prevalence estimates
Suicidal behaviour | Total sample % (95%CI) | Male % (95% CI) | Female % (95%CI) |
---|---|---|---|
Suicide ideation | 20.2 (18.3–22.2) | 20.0 (17.0-23.4) | 20.3 (18.4–22.4) |
Suicide plan | 25.2 (22.3–28.4) | 25.7 (21.8–30.1) | 24.8 (22.0-27.9) |
One-time suicide attempt | 14.6 (12.5–16.9) | 15.2 (12.6–18.4) | 14.0 (11.9–16.5) |
Repeated suicide attempts | 9.9 (8.1–12.1) | 10.9 (8.8–13.6) | 9.1 (7.2–11.4) |
Suicide attempt (overall) | 24.5 (20.9–28.6) | 26.2 (21.6–31.4) | 23.1 (19.7–26.9) |
Bivariate associations
Study Variable | Total sample | Suicidal ideation | Suicidal plan | Suicidal attempt | ||||||
---|---|---|---|---|---|---|---|---|---|---|
N = 3152 | Yes | No | χ2 (p) | Yes | No | χ2 (p) | Yes | No | χ2 (p) | |
n (%) | n (%) | n (%) | n (%) | n (%) | n (%) | n (%) | ||||
Demographics
| ||||||||||
Gender | 0.04 (0.87) | 0.33 (0.61) | 4.0 (0.08) | |||||||
Male | 1380 (44.3) | 278 (20.0) | 1102 (80.0) | 362 (25.7) | 1018 (74.3) | 365 (26.2) | 1015 (73.8) | |||
Female | 1772 (55.7) | 365 (20.3) | 1407 (79.7) | 457 (24.8) | 1315 (75.2) | 429 (23.2) | 1343 (76.8) | |||
School grade |
11.1 (0.001)
|
47.2 (< 0.001)
|
68.8 (< 0.001)
| |||||||
Grade 6–9 | 1918 (60.5) | 423 (22.1) | 1495 (77.9) | 576 (29.3) | 1342 (70.7) | 576 (29.6) | 1342 (70.4) | |||
Grade 10–12 | 1183 (39.5) | 209 (17.2) | 974 (82.8) | 224 (18.4) | 959 (81.6) | 202 (16.5) | 981 (83.5) | |||
Mental health and lifestyle factors
| ||||||||||
Loneliness |
48.3 (< 0.001)
|
42.7 (< 0.001)
|
44.7 (< 0.001)
| |||||||
Yes | 449 (14.3) | 146 (32.3) | 303 (67.7) | 171 (37.7) | 278 (62.3) | 170 (37.0) | 279 (63.0) | |||
No | 2673 (85.8) | 488 (18.1) | 2185 (81.9) | 643 (23.2) | 2030 (76.8) | 614 (22.3) | 2059 (77.7) | |||
Worry/anxiety |
38.7 (< 0.001)
|
50.0 (< 0.001)
|
51.4 (< 0.001)
| |||||||
Yes | 435 (13.8) | 138 (31.3) | 297 (68.8) | 169 (39.0) | 266 (61.0) | 167 (38.2) | 268 (61.8) | |||
No | 2699 (86.2) | 499 (18.3) | 2200 (81.7) | 647 (23.1) | 2052 (76.9) | 620 (22.2) | 2079 (77.8) | |||
Alcohol use |
8.6 (0.01)
|
4.9 (0.02)
|
3.6 (0.04)
| |||||||
Yes | 860 (29.3) | 204 (23.4) | 656 (76.6) | 247 (28.0) | 613 (72.0) | 234 (26.6) | 626 (73.4) | |||
No | 2120 (70.7) | 400 (18.7) | 1720 (81.3) | 531 (24.2) | 1589 (75.8) | 511 (23.3) | 1609 (76.7) | |||
Leisure-time sedentary behaviour |
4.6 (0.01)
| 5.2 (0.06) | 1.5 (0.29) | |||||||
Yes | 1138 (36.4) | 248 (21.9) | 890 (78.1) | 320 (27.4) | 818 (72.6) | 301 (25.5) | 837 (74.5) | |||
No | 1966 (63.6) | 377 (18.7) | 1589 (81.3) | 483 (23.8) | 1483 (76.2) | 475 (23.6) | 1491 (76.4) | |||
Cannabis use |
47.4 (< 0.001)
|
25.9 (0.001)
|
60.4 (< 0.001)
| |||||||
Yes | 134 (4.6) | 58 (42.4) | 76 (57.6) | 59 (42.8) | 75 (57.2) | 72 (50.8) | 62 (49.2) | |||
No | 2909 (95.4) | 552 (18.7) | 2357 (81.3) | 715 (23.8) | 2194 (76.2) | 668 (22.3) | 2241 (77.7) | |||
Interpersonal factors
| ||||||||||
Being sexually active |
17.9 (0.001)
|
16 (0.004)
|
10.4 (0.01)
| |||||||
Yes | 958 (33.5) | 228 (24.0) | 730 (76.0) | 456 (22.2) | 1495 (77.8) | 260 (25.6) | 698 (73.4) | |||
No | 1951 (66.5) | 349 (17.4) | 1602 (82.6) | 279 (29.1) | 679 (70.9) | 431 (21.2) | 1520 (78.8) | |||
Close friends | 2.1 (0.20) |
7.4 (0.03)
| 0.2 (0.71) | |||||||
None | 403 (13.0) | 93 (22.7) | 310 (77.3) | 125 (30.6) | 278 (69.5) | 105 (25.1) | 298 (74.9) | |||
One or more | 2701 (87.0) | 536 (19.7) | 2165 (80.3) | 677 (24.2) | 2024 (75.8) | 670 (24.2) | 2031 (75.8) | |||
Physical fight | 28.3 (< 0.001) |
67.7 (< 0.001)
|
127.7 (< 0.001)
| |||||||
Yes | 1074 (34.4) | 274 (25.5) | 800 (74.5) | 378 (34.1) | 696 (65.9) | 402 (36.4) | 672 (63.6) | |||
No | 2065 (65.6) | 366 (17.4) | 1699 (82.6) | 438 (20.6) | 1627 (79.4) | 358 (18.1) | 1680 (81.9) | |||
School-level factors
| ||||||||||
Physical attack |
51.3 (< 0.001)
|
81.2 (< 0.001)
|
184.6 (< 0.001)
| |||||||
Yes | 1253 (39.8) | 327 (26.5) | 926 (73.5) | 429 (33.8) | 824 (66.2) | 472 (37.4) | 781 (62.6) | |||
No | 1859 (60.2) | 308 (16.0) | 1551 (84.0) | 379 (19.5) | 1480 (80.5) | 313 (16.0) | 1546 (84.0) | |||
Truancy |
23.0 (0.001)
|
65.5 (< 0.001)
|
84.7 (< 0.001)
| |||||||
Yes | 747 (24.0) | 193 (26.2) | 554 (73.8) | 273 (36.5) | 474 (63.5) | 279 (36.9) | 468 (36.1) | |||
No | 2355 (76.0) | 436 (18.1) | 1919 (81.9) | 535 (21.7) | 1820 (78.3) | 497 (20.3) | 1858 (79.7) | |||
Peer support | 0.1 (0.78) | 2.1 (0.27) | 0.5 (0.52) | |||||||
Yes | 853 (27.1) | 179 (20.6) | 674 (79.4) | 239 (26.9) | 614 (73.1) | 223 (25.2) | 630 (74.8) | |||
No | 2270 (72.9) | 459 (20.0) | 1811 (80.0) | 570 (24.4) | 1700 (75.6) | 558 (24.0) | 1712 (76.0) | |||
Bullying victimisation |
36.5 (< 0.001)
|
60.5 (< 0.001)
|
144.0 (< 0.001)
| |||||||
Yes | 1311 (44.7) | 326 (25.3) | 985 (74.7) | 415 (31.8) | 896 (68.2) | 448 (34.1) | 863 (65.9) | |||
No | 1577 (55.4) | 264 (16.3) | 1313 (83.7) | 319 (19.2) | 1258 (80.8) | 247 (15.0) | 1330 (85.0) | |||
Family-level factors
| ||||||||||
Parental supervision | 1.3 (0.40) |
23.1 (0.001)
|
17.5 (0.01)
| |||||||
Yes | 1369 (42.9) | 290 (21.0) | 1079 (79.0) | 412 (29.3) | 957 (70.7) | 389 (28.1) | 980 (72.0) | |||
No | 1743 (57.1) | 342 (19.3) | 1401 (80.7) | 392 (21.8) | 1351 (78.2) | 389 (21.5) | 1354 (78.5) | |||
Parental understanding | 4.9 (0.07) | 2.3 (0.26) | 0.1 (0.71) | |||||||
Yes | 1288 (40.9) | 238 (18.2) | 1050 (81.8) | 314 (23.6) | 974 (76.4) | 315 (23.8) | 973 (76.2) | |||
No | 1794 (59.1) | 389 (21.4) | 1405 (78.6) | 482 (26.0) | 1312 (74.0) | 450 (24.4) | 1344 (75.6) | |||
Parental monitoring | 1.0 (0.33) | 0.1 (0.86) |
6.3 (0.03)
| |||||||
Yes | 1104 (35.1) | 214 (19.1) | 890 (80.9) | 290 (24.8) | 814 (75.2) | 253 (21.7) | 851 (78.3) | |||
No | 2018 (64.9) | 420 (20.6) | 1598 (79.4) | 516 (25.2) | 1502 (74.8) | 529 (25.8) | 1489 (74.3) | |||
Parental intrusion of privacy |
16.0 (0.002)
|
19 (0.002)
|
41.1 (< 0.001)
| |||||||
Yes | 1764 (56.7) | 313 (17.5) | 1451 (82.5) | 401 (22.1) | 1363 (77.9) | 363 (20.0) | 1401 (80.0) | |||
No | 1356 (43.3) | 319 (23.3) | 1037 (76.7) | 405 (29.0) | 951 (71.0) | 416 (30.0) | 940 (70.0) | |||
Food insecurity |
13.9 (0.001)
|
22.3 (0.001)
|
38.3 (< 0.001)
| |||||||
Yes | 310 (9.9) | 87 (28.3) | 223 (71.7) | 113 (36.3) | 197 (63.7) | 119 (38.8) | 191 (61.2) | |||
No | 2796 (90.1) | 546 (19.3) | 2250 (80.7) | 692 (24.0) | 2104 (76.0) | 659 (22.8) | 2137 (77.2) |
Multivariate associations
Variable | Suicide Ideation (N = 2199) | Suicide Plan (N = 2199) | Suicide Attempt (N = 2199) | ||||||
---|---|---|---|---|---|---|---|---|---|
β | AOR [95% CI] | p-value | β | AOR [95% CI] | p-value | β | AOR [95 CI] | p-value | |
Demographics
| |||||||||
Gender: | |||||||||
Female | 1 | 1 | 1 | ||||||
Male | -0.15 | 0.86 [0.64, 1.15] | 0.309 | -0.19 | 0.82 [0.66, 1.03] | 0.088 | -0.09 | 0.91 [0.77, 1.08] | 0.269 |
Age |
0.12
|
1.13 [1.04, 1.22]
|
0.004
| 0.10 | 1.11 [0.99, 1.23] | 0.061 |
0.10
|
1.10 [1.00, 1.21]
|
0.047
|
School grade: | |||||||||
Grade 6–9 | 1 | 1 | 1 | ||||||
Grade 10–12 |
-0.41
|
0.66 [0.52, 0.85]
|
0.002
|
-0.64
|
0.52 [0.40, 0.70]
|
< 0.001
|
-0.72
|
0.49 [0.35, 0.69]
|
< 0.001
|
Mental health and lifestyle factors
| |||||||||
Loneliness |
0.54
|
1.71 [1.22, 2.39]
|
0.003
|
0.54
|
1.71 [1.27, 2.29]
|
0.001
|
0.47
|
1.60
[1.17, 2.18]
|
0.005
|
Worry/anxiety |
0.40
|
1.49
[1.13, 1.96]
|
0.007
|
0.44
|
1.56 [1.11, 2.18]
|
0.013
| 0.31 | 1.36 [0.94, 1.97] | 0.104 |
Alcohol use | 0.15 | 1.16 [0.81, 1.66] | 0.389 | 0.17 | 1.19 [0.91, 1.54] | 0.189 | 0.05 | 1.05 [0.76, 1.46] | 0.769 |
Leisure-time sedentary behaviour |
0.32
|
1.36 [1.08, 1.72]
|
0.009
| 0.22 | 1.25 [0.96, 1.63] | 0.090 | 0.10 | 1.11 [0.83, 1.49] | 0.479 |
Cannabis use | 0.35 | 1.42 [0.84, 2.42] | 0.182 | 0.48 | 1.61 [0.99, 2.64] | 0.057 |
0.78
|
2.18
[1.29, 3.67]
|
0.005
|
Interpersonal factors
| |||||||||
Being sexually active | 0.20 | 1.22 [0.93, 1.60] | 0.147 | 0.30 | 1.34 [0.99, 1.81] | 0.054 | 0.18 | 1.20 [0.95, 1.53] | 0.125 |
Close friends | 0.08 | 1.08 [0.72, 1.63] | 0.694 | -0.14 | 0.87 [0.58, 1.31] | 0.480 | 0.06 | 1.06 [0.73, 1.54] | 0.745 |
Physical fight | 0.18 | 1.19 [0.84, 1.70] | 0.309 |
0.30
|
1.35 [1.00, 1.83]
|
0.048
| 0.21 | 1.24 [0.93, 1.65] | 0.141 |
School-level factors
| |||||||||
Physical attack |
0.42
|
1.53 [1.15, 2.03]
|
0.005
|
0.41
|
1.51 [1.15, 1.99]
|
0.005
|
0.69
|
1.99 [1.56, 2.56]
|
< 0.001
|
Truancy | -0.05 | 0.96 [0.68, 1.35] | 0.788 | 0.19 | 1.21 [0.88, 1.66] | 0.236 | 0.17 | 1.19 [0.83, 1.70] | 0.338 |
Peer support | 0.07 | 1.08 [0.81, 1.44] | 0.609 | 0.25 | 1.28 [0.96, 1.72] | 0.091 | 0.20 | 1.22 [0.96, 1.54] | 0.098 |
Bullying victimisation | 0.18 | 1.20 [0.93, 1.54] | 0.157 |
0.35
|
1.42 [1.12, 1.79]
|
0.005
|
0.61
|
1.83 [1.39, 2.42]
|
< 0.001
|
Family-level factors
| |||||||||
Parental supervision | 0.07 | 1.06 [0.82, 1.40] | 0.619 |
0.38
|
1.46 [1.12, 1.90]
|
0.006
| 0.26 | 1.29 [0.98, 1.70] | 0.069 |
Parental understanding | -0.26 | 0.77 [0.56, 1.06] | 0.106 | -0.21 | 0.81 [0.59, 1.12] | 0.202 | 0.16 | 1.17 [0.92, 1.48] | 0.187 |
Parental monitoring | -0.07 | 0.93 [0.76, 1.14] | 0.478 | -0.04 | 0.96 [0.72, 1.27] | 0.751 |
-0.32
|
0.73 [0.57, 0.94]
|
0.016
|
Parental intrusion of privacy |
0.29
|
1.34 [1.04, 1.73]
|
0.024
|
0.25
|
1.29 [1.00, 1.65]
|
0.047
|
0.44
|
1.55 [1.21, 1.99]
|
0.001
|
Food insecurity | 0.23 | 1.26 [0.89, 1.78] | 0.181 | -0.07 | 0.93 [0.71, 1.23] | 0.602 | 0.15 | 1.16 [0.82, 1.65] | 0.392 |
McFadden’s R2 | 0.054 | 0.08 | 0.110 | ||||||
McKelvey and Zavoina’s R2 | 0.090 | 0.14 | 0.182 | ||||||
Hosmer–Lemeshow GOF test (sig.) | 2072 (0.30) | 2064 (0.35) | 2011 (0.67) | ||||||
Overall percentage correctly classified | 81.40% | 76.40% | 79.45% |
Variable | One-time attempt | Repeated attempts | ||||
---|---|---|---|---|---|---|
β | ARRR [95% CI] | p-value | β | ARRR [95 CI] | p-value | |
Demographics
| ||||||
Gender: | ||||||
Female | 1 | 1 | ||||
Male | -0.02 | 0.98 [0.80, 1.20] | 0.849 | 0.11 | 1.12 [0.86, 1.45] | 0.395 |
Age |
0.12
|
1.13 [1.03, 1.24]
|
0.013
| 0.10 | 1.10 [0.96, 1.27] | 0.164 |
School grade: | ||||||
Grade 6–9 | 1 | 1 | ||||
Grade 10–12 |
-0.69
|
0.50 [0.36, 0.70]
|
< 0.001
|
-0.67
|
0.51 [0.35, 0.75]
|
0.001
|
Mental health and lifestyle factors
| ||||||
Loneliness |
0.43
|
1.54 [1.05, 2.25]
|
0.028
|
0.72
|
2.06 [1.27, 3.35]
|
0.005
|
Cannabis use | 0.26 | 1.29 [0.65, 2.58] | 0.455 |
1.31
|
3.72 [2.08, 6.65]
|
< 0.001
|
School-level factors
| ||||||
Physical attack |
0.65
|
1.92 [1.47, 2.50]
|
< 0.001
|
1.07
|
2.92 [2.28, 3.74]
|
< 0.001
|
Bullying victimisation |
0.52
|
1.68 [1.27, 2.22]
|
0.001
|
0.96
|
2.60 [1.83, 3.70]
|
< 0.001
|
Family-level factors
| ||||||
Parental monitoring | -0.22 | 0.80 [0.61, 1.05] | 0.108 | -0.20 | 0.82 [0.57, 1.18] | 0.269 |
Parental intrusion of privacy |
0.35
|
1.41 [1.13, 1.76]
|
0.003
|
0.58
|
1.78 [1.30, 2.44]
|
0.001
|