Descriptive statistics of studied variables stratified by gender (Slovakia, 2022, N=10 163, mean age 13.4 years)
| Characteristics | Whole sample | Boys | Girls | Pearson χ2 value | P value | |
| n (%) | n (%) | n (%) | ||||
| PARI | ||||||
| Sports clubs | With injury | 2316 (55.1) | 1412 (60.4) | 904 (48.4) | 59.874 | <0.0001 |
| No injury | 1888 (44.9) | 926 (39.6) | 962 (51.6) | |||
| Leisure time | With injury | 3971 (42.9) | 2169 (46.7) | 1802 (39.1) | 53.714 | <0.0001 |
| No injury | 5285 (57.1) | 2480 (53.3) | 2805 (60.9) | |||
| School | With injury | 2521 (27.9) | 1290 (28.5) | 1231 (27.4) | 1.489 | 0.222 |
| No injury | 6500 (72.1) | 3233 (71.5) | 3267 (72.6) | |||
| Sleep problems | ||||||
| Problem with falling asleep | At least once a week | 3145 (31.6) | 1222 (24.2) | 1923 (39.2) | 259.237 | <0.0001 |
| No problem | 6799 (68.4) | 3822 (75.8) | 2977 (60.8) | |||
| Waking up at night | At least once a week | 2486 (25.2) | 963 (19.3) | 1523 (31.3) | 189.811 | <0.0001 |
| No problem | 7377 (74.8) | 4036 (80.7) | 3341 (68.7) | |||
| Problem with waking up in the morning and feeling rested | At least once a week | 5030 (51.1) | 2142 (42.9) | 2888 (59.5) | 271.394 | <0.0001 |
| No problem | 4815 (48.9) | 2850 (57.1) | 1965 (40.5) | |||
| Day sleepiness | At least once a week | 5019 (50.9) | 2035 (40.7) | 2984 (61.3) | 417.922 | <0.0001 |
| No problem | 4840 (49.1) | 2959 (59.3) | 1881 (38.7) | |||
| Sleep duration* | ||||||
| Schooldays | Short | 3936 (39.7) | 1876 (37.2) | 2060 (42.2) | 26.031 | <0.0001 |
| Normal | 5957 (60) | 3143 (62.4) | 2814 (57.6) | |||
| Long | 31 (0.3) | 19 (0.4) | 12 (0.2) | |||
| Weekends | Short | 1347 (14.6) | 781 (16.5) | 566 (12.6) | 52.488 | <0.0001 |
| Nromal | 5851 (63.4) | 3035 (64.1) | 2816 (62.8) | |||
| Long | 2026 (22) | 921 (19.4) | 1105 (24.6) | |||
*Sleep duration was calculated using the cut-offs for short and long sleep duration from Sawyer et al.25
PARI, physical activity-related injury.