Table 2.
Prevalence of sleep and mental health outcomes by school start time.
| Level | Factor | Overall, % (95% CI) |
Schools with Very Early Start Times, % (95% CI) |
Schools with Early Start Times, % (95% CI) |
Schools with Late Start Times, % (95% CI) |
p-Value |
|---|---|---|---|---|---|---|
| Students | Total Responses | 46,537 | 21,236 (53.2%) | 18,754 (28.2%) | 6547 (18.5%) | |
| Sleep Duration | <0.01 | |||||
| 4 h or less | 8.9 (8.5, 9.3) | 10.4 (9.9, 11.0) | 7.8 (7.2, 8.3) | 6.1 (5.0, 7.1) | ||
| 5 h | 12.3 (11.8, 12.8) | 13.8 (13.1, 14.6) | 11.4 (10.6, 12.2) | 9.4 (8.2, 10.6) | ||
| 6 h | 23.3 (22.7, 23.9) | 24.7 (23.8, 25.6) | 22.7 (22.0, 23.5) | 20.0 (18.2, 21.7) | ||
| 7 h | 29.5 (29.0, 30.1) | 27.8 (27.0, 28.7) | 31.0 (29.8, 32.1) | 32.3 (31.1, 33.5) | ||
| 8 h | 19.9 (19.3, 20.5) | 17.8 (16.9, 18.7) | 20.7 (20.0, 21.4) | 24.4 (22.5, 26.4) | ||
| 9 h | 4.6 (4.3, 4.8) | 3.7 (3.3, 4.1) | 4.8 (4.3, 5.2) | 6.7 (5.8, 7.6) | ||
| 10 h or more | 1.6 (1.4, 1.7) | 1.7 (1.5, 1.9) | 1.7 (1.5, 1.9) | 1.1 (0.8, 1.4) | ||
| Sleep Health | ||||||
| 8 h or more | 26.0 (25.2, 26.8) | 23.2 (22.0, 24.4) | 27.2 (26.2, 28.2) | 32.2 (29.5, 35.0) | <0.01 | |
| Mental Health | ||||||
| Considered suicide, past 12 months | 17.5 (17.0, 17.9) | 17.8 (17.0, 18.5) | 17.2 (16.4, 17.9) | 17.0 (16.0, 18.0) | 0.56 | |
| Attempted suicide, past 12 months | 7.6 (7.2, 8.0) | 8.0 (7.5, 8.5) | 7.9 (7.0, 8.7) | 6.1 (5.5, 6.8) | 0.03 |
This table collects the prevalence of sleep duration, sleep health, suicidal ideation, and suicide attempts, both overall and stratified by school start time. The presented p-values test for bivariate associations and are estimated based on the second order Rao–Scott chi-square test. Abbreviations: CI, confidence interval; h, hours.