Table 2. Association Between Sleep Disturbance and Suicidal Behavior, Adjusting for Covariatesa .
| Variable | Suicidal behavior | |
|---|---|---|
| OR (95% CI) | P value | |
| Sleep disturbanceb | ||
| Minimal | 1 [Reference] | 1 [Reference] |
| Moderate | 1.17 (0.98-1.38) | .08 |
| Elevated | 1.19 (0.85-1.66) | .31 |
| High | 1.39 (1.00-1.94) | .05 |
| Severe | 2.68 (1.44-4.98) | .002 |
| Anxiety and depressionc | 1.66 (1.46-1.89) | <.001 |
| Family history of depressiond | 1.14 (1.06-1.22) | <.001 |
| Family conflicte | 1.08 (1.00-1.17) | .04 |
| Parental monitoringf | 0.85 (0.79-0.92) | <.001 |
Abbreviation: OR, odds ratio.
This model also included the following covariates as fixed effects: study site, race, ethnicity, age, sex assigned at birth, parental educational level, parental marital status, annual household income, and parental employment status. There were 8807 observations, and the Nagelkerke R2 was 0.046.
Sleep disturbance was assessed with the Sleep Disturbance Scale for Children, with scores ranging from 26 to 130. Cut points from a norming sample were used to categorize sleep disturbance as minimal (26-35), moderate (36-46), elevated (47-51), high (52-66), or severe (67-130). Minimal was the reference group.
Anxiety and depression were estimated from the Child Behavior Checklist T score for Anxiety and Depression subscale, and the raw T score was scaled by dividing by 10 so that an increase in 10 points was associated with a 1.66 increase in risk of suicidal behavior.
Family history of depression was a family history density (FHD) score, which assesses history of depression in parents, grandparents, aunts, uncles, and siblings as well as reflects the frequency of depression and the genetic proximity (eg, parents are weighted more heavily than uncles). The FHD score was z scored, with a mean of 0 and an SD of 1, such that an increase in 1 SD was associated with a 1.14 increased risk in suicidal behavior.
Family conflict was assessed with the youth-reported Family Environment Scale. The total score was z scored, with a mean of 0 and an SD of 1, such that an increase in 1 SD was associated with a 1.08 increased risk in suicidal behavior.
Parental monitoring was assessed with the Parental Monitoring Scale. The total score was z scored, with a mean of 0 and an SD of 1, such that an increase in 1 SD was associated with a 0.85 decreased risk in suicidal behavior.