TABLE 8.
Subgroup Analyses for the Association Between School Start Time and Youth Outcomes by Youth and School Characteristics
| 95% CI | ||||||||
|---|---|---|---|---|---|---|---|---|
| Moderator | Developmental Outcomes | Category | n | k | ES | Lower | Upper | P |
|
| ||||||||
| School level | Aggregated outcome | Elementary school | 5 | 46 | 0.113 | 0.055 | 0.171 | .006** |
| Middle school | 11 | 147 | 0.062 | −0.023 | 0.147 | .13 | ||
| High school | 21 | 304 | 0.045 | −0.001 | 0.091 | .05*** | ||
| Secondary school | 22 | 336 | 0.058 | 0.004 | 0.112 | .03* | ||
| Sleep | Elementary school | 4 | 34 | — | — | — | — | |
| Middle school | 9 | 91 | 0.032 | −0.142 | 0.207 | .68 | ||
| High school | 20 | 228 | 0.034 | −0.035 | 0.103 | .32 | ||
| Secondary school | 19 | 229 | 0.044 | −0.040 | 0.128 | .28 | ||
| Duration | Elementary school | 4 | 14 | — | — | — | — | |
| Middle school | 9 | 37 | 0.087 | −0.147 | 0.322 | .42 | ||
| High school | 18 | 72 | 0.096 | 0.007 | 0.185 | .03* | ||
| Secondary school | 18 | 74 | 0.098 | −0.012 | 0.209 | .08*** | ||
| Quality | Elementary schoola | — | — | — | — | — | — | |
| Middle school | 3 | 5 | — | — | — | — | ||
| High school | 8 | 37 | −0.068 | −0.130 | −0.006 | .04* | ||
| Secondary school | 8 | 37 | −0.050 | −0.126 | 0.027 | .16 | ||
| Bedtime | Elementary school | 3 | 7 | — | — | — | — | |
| Middle school | 6 | 18 | 0.077 | −0.171 | 0.325 | .46 | ||
| High school | 14 | 45 | 0.047 | −0.072 | 0.167 | .42 | ||
| Secondary school | 12 | 43 | 0.014 | −0.053 | 0.080 | .66 | ||
| Wake time | Elementary school | 3 | 7 | — | — | — | — | |
| Middle school | 6 | 17 | 0.015 | −0.368 | 0.399 | .92 | ||
| High school | 11 | 38 | 0.092 | −0.173 | 0.356 | .46 | ||
| Secondary school | 10 | 37 | −0.179 | −0.422 | 0.064 | .13 | ||
| Chronotype | Elementary schoola | — | — | — | — | — | — | |
| Middle schoola | — | — | — | — | — | — | ||
| High school | 6 | 9 | −0.037 | −0.189 | 0.115 | .55 | ||
| Secondary school | 5 | 8 | — | — | — | — | ||
| Sleepiness | Elementary school | 2 | 6 | — | — | — | — | |
| Middle school | 4 | 12 | — | — | — | — | ||
| High school | 9 | 18 | 0.144 | −0.042 | 0.329 | .11 | ||
| Secondary school | 9 | 21 | 0.127 | −0.065 | 0.318 | .16 | ||
| Socioemotional | Elementary schoola | — | — | — | — | — | — | |
| Middle school | 3 | 19 | — | — | — | — | ||
| High school | 7 | 34 | 0.052 | −0.006 | 0.110 | .07† | ||
| Secondary school | 7 | 34 | 0.052 | −0.006 | 0.110 | .07† | ||
| Negative | Elementary schoola | — | — | — | — | — | — | |
| Middle school | 3 | 14 | — | — | — | — | ||
| High school | 6 | 22 | 0.068 | 0.003 | 0.132 | .04* | ||
| Secondary school | 6 | 22 | 0.068 | 0.003 | 0.132 | .04* | ||
| Academic | Elementary school | 1 | 10 | — | — | — | — | |
| Middle school | 3 | 29 | — | — | — | — | ||
| High school | 5 | 13 | −0.050 | −0.147 | 0.047 | .22 | ||
| Secondary school | 7 | 40 | 0.028 | −0.162 | 0.217 | .73 | ||
| School sector | Aggregated outcome | Public school | 20 | 254 | 0.050 | −0.010 | 0.110 | .09+ |
| Private school | 7 | 74 | 0.122 | 0.033 | 0.210 | .01* | ||
| Sleep | Public school | 17 | 171 | 0.026 | −0.066 | 0.118 | .55 | |
| Private school | 7 | 66 | 0.129 | 0.038 | 0.220 | .01* | ||
| Duration | Public school | 15 | 55 | 0.088 | −0.044 | 0.220 | .17 | |
| Private school | 7 | 23 | 0.149 | 0.018 | 0.281 | .03* | ||
| Quality | Public school | 8 | 22 | — | — | — | — | |
| Private school | 2 | 10 | — | — | — | — | ||
| Bedtime | Public school | 10 | 30 | 0.001 | −0.106 | 0.107 | .99 | |
| Private school | 4 | 11 | — | — | — | — | ||
| Wake time | Public school | 10 | 28 | 0.081 | −0.252 | 0.414 | .60 | |
| Private school | 4 | 10 | — | — | — | — | ||
| Chronotype | Public school | 5 | 7 | — | — | — | — | |
| Private school | 2 | 4 | — | — | — | — | ||
| Sleepiness | Public school | 8 | 18 | 0.044 | −0.026 | 0.113 | .17 | |
| Private school | 2 | 5 | — | — | — | — | ||
| Socioemotional | Public school | 5 | 24 | — | — | — | — | |
| Private school | 1 | 4 | — | — | — | — | ||
| Negative | Public school | 4 | 15 | — | — | — | — | |
| Private schoola | — | — | — | — | — | — | ||
| Academic | Public school | 6 | 49 | 0.051 | −0.178 | 0.280 | .59 | |
| Private schoola | — | — | — | — | — | — | ||
| Urbanicity | Aggregated outcome | Urban | 9 | 139 | 0.113 | −0.023 | 0.249 | .09*** |
| Suburb | 6 | 34 | 0.127 | −0.056 | 0.310 | .13 | ||
| Rural | 2 | 14 | — | — | — | — | ||
| Sleep | Urban | 7 | 89 | 0.087 | −0.031 | 0.205 | .12 | |
| Suburb | 4 | 16 | — | — | — | — | ||
| Rurala | — | — | — | — | — | — | ||
| Duration | Urban | 7 | 23 | 0.131 | −0.025 | 0.286 | .08*** | |
| Suburb | 4 | 6 | — | — | — | — | ||
| Rurala | — | — | — | — | — | — | ||
| Quality | Urban | 2 | 22 | — | — | — | — | |
| Suburba | — | — | — | — | — | — | ||
| Rurala | — | — | — | — | — | — | ||
| Bedtime | Urban | 5 | 14 | — | — | — | — | |
| Suburb | 2 | 3 | — | — | — | — | ||
| Rurala | — | — | — | — | — | — | ||
| Wake time | Urban | 4 | 13 | — | — | — | — | |
| Suburba | — | — | — | — | — | — | ||
| Rurala | — | — | — | — | — | — | ||
| Chronotype | Urban | 2 | 3 | — | — | — | — | |
| Suburba | — | — | — | — | — | — | ||
| Rurala | — | — | — | — | — | — | ||
| Sleepiness | Urban | 4 | 12 | — | — | — | — | |
| Suburb | 2 | 4 | — | — | — | — | ||
| Rurala | — | — | — | — | — | — | ||
| Socioemotional | Urban | 2 | 15 | — | — | — | — | |
| Suburba | — | — | — | — | — | — | ||
| Rurala | — | — | — | — | — | — | ||
| Negative | Urban | 2 | 11 | — | — | — | — | |
| Suburba | — | — | — | — | — | — | ||
| Rurala | — | — | — | — | — | — | ||
| Academic | Urban | 3 | 14 | — | — | — | — | |
| Suburb | 2 | 12 | — | — | — | — | ||
| Rurala | — | — | — | — | — | — | ||
| Region | Aggregated outcome | West | 2 | 19 | — | — | — | — |
| South | 4 | 24 | — | — | — | — | ||
| Northeast | 7 | 113 | 0.078 | −0.049 | 0.205 | .18 | ||
| Midwest | 3 | 40 | — | — | — | — | ||
| Multi | 5 | 57 | — | — | — | — | ||
| Sleep | West | 2 | 17 | — | — | — | — | |
| South | 2 | 7 | — | — | — | — | ||
| Northeast | 7 | 89 | 0.082 | −0.052 | 0.216 | .18 | ||
| Midwest | 2 | 7 | — | — | — | — | ||
| Multi | 5 | 53 | — | — | — | — | ||
| Duration | West | 2 | 4 | — | — | — | — | |
| South | 2 | 3 | — | — | — | — | ||
| Northeast | 7 | 20 | 0.127 | −0.030 | 0.284 | .09*** | ||
| Midwest | 2 | 3 | — | — | — | — | ||
| Multi | 5 | 18 | — | — | — | — | ||
| Quality | Westa | — | — | — | — | — | — | |
| Southa | — | — | — | — | — | — | ||
| Northeast | 3 | 8 | — | — | — | — | ||
| Midwest | — | — | — | — | ||||
| Multi | 2 | 9 | — | — | — | — | ||
| Bedtime | West | 2 | 4 | — | — | — | — | |
| Southa | — | — | — | — | — | — | ||
| Northeast | 7 | 20 | −0.004 | −0.118 | 0.110 | .94 | ||
| Midwesta | — | — | — | — | — | — | ||
| Multi | 3 | 10 | — | — | — | — | ||
| Wake time | West | 2 | 4 | — | — | — | — | |
| Southa | — | — | — | — | — | — | ||
| Northeast | 6 | 16 | 0.211 | −0.165 | 0.587 | .21 | ||
| Midwesta | — | — | — | — | — | — | ||
| Multi | 3 | 10 | — | — | — | — | ||
| Chronotype | Westa | — | — | — | — | — | — | |
| Southa | — | — | — | — | — | — | ||
| Northeast | 2 | 4 | — | — | — | — | ||
| Midwesta | — | — | — | — | — | — | ||
| Multia | — | — | — | — | — | — | ||
| Sleepiness | Westa | — | — | — | — | — | — | |
| Southa | — | — | — | — | — | — | ||
| Northeast | 4 | 10 | — | — | — | — | ||
| Midwesta | — | — | — | — | — | — | ||
| Multia | — | — | — | — | — | — | ||
| Socioemotional | Westa | — | — | — | — | — | — | |
| Southa | — | — | — | — | — | — | ||
| Northeasta | — | — | — | — | — | — | ||
| Midwesta | — | — | — | — | — | — | ||
| Multia | — | — | — | — | — | — | ||
| Negative | Westa | — | — | — | — | — | — | |
| Southa | — | — | — | — | — | — | ||
| Northeasta | — | — | — | — | — | — | ||
| Midwesta | — | — | — | — | — | — | ||
| Multia | — | — | — | — | — | — | ||
| Academic | Westa | — | — | — | — | — | — | |
| South | 2 | 12 | — | — | — | — | ||
| Northeast | 2 | 4 | — | — | — | — | ||
| Midwest | 1 | 33 | — | — | — | — | ||
| Multia | — | — | — | — | — | — | ||
| Geography | Aggregated outcome | NA | 19 | 278 | 0.061 | 0.002 | 0.119 | .04* |
| EU | 3 | 36 | — | — | — | — | ||
| Asia | 4 | 117 | — | — | — | — | ||
| Sleep | NA | 16 | 196 | 0.035 | −0.049 | 0.119 | .39 | |
| EU | 3 | 12 | — | — | — | — | ||
| Asia | 4 | 89 | — | — | — | — | ||
| Duration | NA | 15 | 53 | 0.082 | −0.021 | 0.186 | .11 | |
| EU | 2 | 5 | — | — | — | — | ||
| Asia | 4 | 33 | — | — | — | — | ||
| Quality | NA | 7 | 21 | — | — | — | — | |
| EUa | — | — | — | — | — | — | ||
| Asia | 2 | 19 | — | — | — | — | ||
| Bedtime | NA | 12 | 44 | 0.052 | −0.086 | 0.189 | .42 | |
| EU | 1 | 2 | −0.157 | — | — | — | ||
| Asia | 4 | 12 | — | — | — | — | ||
| Wake time | NA | 11 | 40 | 0.076 | −0.206 | 0.358 | .56 | |
| EUa | — | — | — | — | — | — | ||
| Asia | 3 | 11 | — | — | — | — | ||
| Chronotype | NA | 5 | 9 | — | — | — | — | |
| EU | 2 | 3 | — | — | — | — | ||
| Asiaa | — | — | — | — | — | — | ||
| Sleepiness | NA | 6 | 12 | 0.100 | −0.081 | 0.280 | .21 | |
| EU | 2 | 2 | — | — | — | — | ||
| Asia | 4 | 14 | — | — | — | — | ||
| Socioemotional | NA | 4 | 17 | — | — | — | — | |
| EU | 1 | 2 | — | — | — | — | ||
| Asia | 3 | 24 | — | — | — | — | ||
| Negative | NA | 3 | 13 | — | — | — | — | |
| EUa | — | — | — | — | — | — | ||
| Asia | 3 | 17 | — | — | — | — | ||
| Academic | NA | 6 | 50 | 0.075 | −0.141 | 0.290 | .41 | |
| EUa | — | — | — | — | — | — | ||
| Asiaa | — | — | — | — | — | — | ||
Age was adjusted in all analyses. Estimates with df < 4 are not considered to be reliable. ES, effect sizes assessed in correlation; EU, European Union; m, number of effect sizes; n, number of studies; NA, North America; —, refer to analyses where the degrees of freedom was less than 4, which would provide unreliable estimates, therefore estimates were not analyzed.
a
These variables contain issues of convergence.
*
P < .05
***
P < .001
+
P < .10.