Table 4.
Group Differences in ISI Scores While Untreated.
| ISI scores while untreated | Independent samples t test | |
|---|---|---|
| M ± SD (n) | ||
| Gender | ||
| Men | 19.4 ± 4.0 (54) | 3.52; p < .05 |
| Women | 21.7 ± 4.2 (139) | |
| Racea | ||
| White | 21.2 ± 4.2 (149) | 0.90; p = .37 |
| African American | 20.3 ± 4.9 (24) | |
| Smoker | ||
| Yes | 21.2 ± 4.9 (20) | 0.08; p = .94 |
| No | 21.1 ± 4.3 (173) | |
| Medical comorbidity | ||
| Without | 20.7 ± 4.2 (51) | 0.75; p = .45 |
| With | 21.2 ± 4.4 (142) | |
| Psychiatric comorbidity | ||
| Without | 20.2 ± 4.3 (96) | 2.73; p < .05 |
| With | 21.9 ± 4.2 (97) | |
ISI = insomnia severity index; M = mean; n = sample size; SD = standard deviation.
aResults are presented for the 2 most commonly endorsed categories of the Race variable (“White” and “African American”) as there were two few cases of other race categories for meaningful comparisons.