Table 2.
Pretreatment sample characteristics for the full sample and by pretreatment SI status
| Full sample | No baseline SI | Baseline SI | Test statistic, p-value, and effect size | |
|---|---|---|---|---|
| n = 658 | n = 532 | n = 126 | ||
| Age (M ± SD, range) | 45.03 ± 15.42 | 45.89 ± 15.22 | 41.37 ± 15.81 | t(656) = −2.98, p = .003, d = 0.29 |
| Male sex (n; %) | 139; 21.1% | 103; 19.4% | 36; 28.6% | χ2 = 5.19, p = .023, RR = 1.47 |
| Race (n;%) | ||||
| White | 470; 71.4% | 382; 71.8% | 88; 69.8% | χ2 = 0.18, p = .672 |
| Black | 140; 21.3% | 116; 21.8% | 24; 19.0% | Note: chi-square analysis compared SI rates between White and Black as they were the most well-represented groups. |
| Unreported | 20; 3.0% | 14; 2.6% | 6; 4.8% | |
| Asian | 12; 1.8% | 8; 1.5% | 4; 3.2% | |
| Multiracial | 12; 1.8% | 9; 1.7% | 3; 2.4 | |
| Native American | 4; 0.6% | 3; 0.6% | 1; 0.8% | |
| Education level (n;%) | χ2 = 2.11, p = .147 | |||
| No HS or GED (<4) | 15; 2.3% | 9; 1.7% | 6; 4.8% | Note: chi-square analysis compared SI rates between patients with and without college degrees. |
| HS or GED (4–7) | 276; 41.9% | 219; 42.2% | 57; 45.2% | |
| Associates (8) | 84; 12.8% | 72; 13.5% | 12; 9.5% | |
| Bachelors (9 & 10) | 172; 26.1% | 144; 27.1% | 28; 22.2% | |
| Graduate degree (11–12) | 111; 16.9% | 88; 16.5% | 23; 18.3% | |
| Poverty (<$20K) (n;%) | 140; 21.3% | 95; 17.9% | 45; 35.7% | χ2 = 19.39, p < .001, RR = 1.99 |
| ISI (M ± SD) | 17.79 ± 4.29 | 17.67 ± 4.35 | 18.29 ± 4.01 | t(656) = 1.46, p = .146 |
| QIDS-SR16 (M ± SD) | 10.77 ± 4.54 | 9.72 ± 4.07 | 15.21 ± 3.69 | t(656) = 13.88, p < .001, d = 1.41 |
SI, suicidal ideation over the past week, operationalized as endorsing the SI item on the quick inventory of depressive symptomatology, 16-item self-report version; M ± SD, mean and standard deviation; n, number of patients; HS, high school; GED, General Education Development; Associates, associates degree; Bachelors, bachelor's degree; ISI, insomnia severity index; QIDS-SR16, quick inventory of depressive symptomatology, 16-item self-report version; χ2, chi-square; RR, relative risk; d, Cohen’s d effect size.