Table 1.
Demographic and clinical characteristics of the sample. Ranges are provided for clustering variables. Cells show the mean (SD) unless otherwise noted.
| Full Sample (N=154) | Cluster 1 (N=50) | Cluster 2 (N=70) | Cluster 3 (N=34) | Statistic | Pairwise Differences | |
|---|---|---|---|---|---|---|
| Daytime And Nighttime Symptoms Used for Clustering | ||||||
| Sleep Quality (PSQI; Range = 0 - 21) | 9.8 (3.5) | 8.8 (4) | 9.9 (2.8) | 11 (3.5) | F=4.6*** | 1 < 3 |
| DNB (PSQI –A; Range = 0 – 21) | 3.4 (3) | 1 (1.1) | 3.7 (2.5) | 6.3 (3) | F=56.3*** | 1 < 2 < 3 |
| Daytime Intrusions (PCL; Range = 4 –20) | 7.6 (3.3) | 4.9 (0.9) | 7.3 (1.6) | 12.4 (3) | F=168.4*** | 1 < 2 < 3 |
| Daytime Avoidance (PCL; Range = 2-10) | 4.3 (2.2) | 2.5 (0.6) | 4.2 (1.6) | 7.2 (1.5) | F=126.6*** | 1 < 2 < 3 |
| Daytime Dysphoria (PCL; Range = 7-35) | 13.7 (5.6) | 9.5 (2) | 13 (3.2) | 21.1 (6) | F=101.0*** | 1 < 2 < 3 |
| Daytime Hyperarousal (PCL; Range = 2-10) | 4.4 (2.3) | 2.7 (0.8) | 4.5 (1.9) | 6.9 (2) | F=67.4*** | 1 < 2 < 3 |
| Trauma and Combat History | ||||||
| Trauma (“Happened To”) (LEC) | 5.3 (2.5) | 4.5 (2.4) | 5.2 (2.5) | 6.7 (2.1) | F=8.7*** | (1, 2) < 3 |
| Trauma (“Witnessed”) (LEC) | 3.2 (2.7) | 3 (3.1) | 3 (2.2) | 4 (3) | F=2 | |
| Combat Exposure (CES), N=146 | 14.6 (10.9) | 10.4 (9.6) | 15.6 (10.1) | 19.5 (12.5) | F=7.3*** | 1 < (2, 3) |
| Total Number of Deployments, N=142 | 1.3 (0.7) | 1.3 (0.9) | 1.3 (0.7) | 1.1 (0.3) | F=1.1 | |
| Years Since Last Deployment, N=95 | 7 (10.7) | 8 (12.6) | 7.4 (10.1) | 4.7 (8.6) | F=6 | |
| Demographic Characteristics | ||||||
| Army, %(n), N=123 | 65.4 (80) | 59.5 (25) | 66.0 (35) | 71.4 (20) | X2=1.1 | |
| Navy, %(n), N=123 | 18.7 (23) | 23.8 (1) | 17.0 (9) | 14.3 (4) | FE | |
| Air Force, %(n), N=123 | 5.7 (7) | 4.0 (2) | 4.5 (3) | 5.9 (2) | FE | |
| Marines, %(n), N=123 | 10.6 (13) | 11.9 (5) | 11.3 (6) | 7.1 (2) | FE | |
| Military Officer, %(n), N=118 | 22.9 (27) | 30.8 (12) | 21.6 (11) | 14.3 (4) | X2=2.2 | |
| Age | 36.8 (12) | 39 (13.2) | 35.4 (10.7) | 36.6 (12.8) | F=1.3 | |
| Female, %(n) | 14.9 (23) | 14 (7) | 14.3 (10) | 17.6 (6) | X2=.25 | |
| Caucasian, %(n) | 83.1 (128) | 80.0 (40) | 81.4 (57) | 91.2 (31) | X2=2.1 | |
| Clinical Characteristics | ||||||
| Total PCL | 35.3 (12.6) | 23.7 (3.4) | 34.1 (4.9) | 54.6 (9.2) | F=294.7*** | 1 < 2 < 3 |
| Total CAPS | 40.1 (21.2) | 26.5 (15.5) | 40.3 (18.8) | 59.5 (17.9) | F=35.6*** | 1 < 2 < 3 |
| CAPS B (Re-experiencing) | 9.5 (7.4) | 5.2 (5.3) | 9.2 (7.1) | 16.4 (5.7) | F=32.1*** | 1 < 2 < 3 |
| CAPS C (Avoidance, Numbing) | 12.6 (10.3) | 6.6 (7.1) | 12.9 (9.2) | 20.6 (10.9) | F=24.6*** | 1 < 2 < 3 |
| CAPS D (Hyperarousal) | 18 (7) | 14.7 (6.3) | 18.2 (7) | 22.6 (5) | F=15.6*** | 1 < 2 < 3 |
| Anxiety (BAI), N=151 | 6.4 (6.3) | 2.2 (2.3) | 6.2 (5) | 12.8 (7.3) | F=45.2*** | 1 < 2 < 3 |
| Depression (BDI), N=151 | 9.2 (6.8) | 5.2 (4.1) | 8.8 (5.7) | 15.5 (7.5) | F=32.6*** | 1 < 2 < 3 |
| PTSD Diagnosis, % (n) | 46.8 (72) | 20 (10) | 48.6 (34) | 82.4 (28) | X2=31.78*** | 1 < 2 < 3 |
| Taking Any Psychotropic Medications, % (n) | 50 (77) | 32 (16) | 51.4 (36) | 73.5 (25) | X2=14.07*** | 1 < 3 |
Note. ANOVA, Chi-square, and Fisher's exact (FE) tests were used to test for overall differences among clusters. Cells in the “Statistic” column with an “FE” indicate that Fisher's exact test was used. All pair-wise differences were adjusted for multiple comparisons using either Tukey's method (continuous measures) or Bonferroni's correction (dichotomous measures). PSQI = Pittsburgh Sleep Quality Index; PSQI-A = Pittsburgh Sleep Quality Index Addendum; PCL = Posttraumtic Stress Disorder (PSTD) Checklist; LEC = Life Events Checklist; CES = Combat Exposure Scale; CAPS = Clinician-Administered PSTD Scale; BDI = Beck Depression Inventory; BAI = Beck Anxiety Inventory; DNB = disruptive nocturnal behaviors.
p<.05.
p<.01.
p<.001.