Table 3.
Hazard ratio for onset of methylphenidate treatment by covariates, univariable (raw), and multivariable analysis (adjusted)
| Univariable | Multivariable | ||||
|---|---|---|---|---|---|
|
|
|
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| HR | 95% CI | HR | 95%CI | ||
| Sex | Boy | 1 | — | 1 | — |
| Girl | 0.41 | 0.41–0.42 | 0.41 | 0.40–0.41 | |
| Relative age in class | Oldest third | 1 | — | 1 | — |
| Mid-third | 1.08 | 1.06–1.10 | 1.08 | 1.06–1.10 | |
| Youngest third | 1.19 | 1.18–1.21 | 1.19 | 1.17–1.21 | |
| Ethnic sector | Arab | 1 | — | 1 | — |
| Ultra-Orthodox Jews | 2.17 | 2.09–2.23 | 2.24 | 2.16–2.32 | |
| General | 3.18 | 3.11–3.24 | 3.18 | 3.11–3.25 | |
| Birth order among siblings | First | 1 | — | 1 | — |
| Second or third | 1.19 | 1.17–1.21 | 1.19 | 1.17–1.21 | |
| Fourth or subsequent | 1.24 | 1.22–1.26 | 1.23 | 1.21–2.26 | |
| Number of children in family | 1 to 2 | 1 | — | 1 | — |
| 3 to 5 | 1.48 | 1.45–1.50 | 1.64 | 1.61–1.67 | |
| 6 and more | 0.78 | 0.76–0.80 | 1.12 | 1.09–1.16 | |
| SES | Low | 1 | — | 1 | — |
| Medium | 1.76 | 1.73–1.79 | 1.18 | 1.16–1.20 | |
| High | 1.78 | 1.74–1.81 | 1.09 | 1.07–1.11 | |
SES, socioeconomic status at the health clinic level; RR, risk ratio; CI, confidence interval.