Table 3.
Discriminative values (95% CI), symptom severity correlation coefficients (Pearson’s r), and reliability coefficients (Cronbach’s alpha) of different candidates of the PDS 2- or 3-item scale applied to Japanese participants with and without PTSD.
| Short versions of the PDS (DSM-IV Criteria) |
Cut-point |
SN |
(95% CI) |
SP |
(95% CI) |
Efficiency |
(95% CI) |
AUC |
(95% CI) |
r |
(95% CI) |
alpha |
| Two-item version | ||||||||||||
| (B1, B2) | 1/2 | 94.8 | (90.4–97.5) | 86.1 | (80.1–89.7) | 91.1 | (86–94.2) | 0.94 | (0.90–0.98) | .82 | (76–86.2) | .82 |
| (B1, B3) | 1/2 | 90.7 | (85.7–94.3) | 83.3 | (76.6–88.1) | 87.6 | (81.8–91.7) | 0.91 | (85.8–95.8) | .76 | (68.5–81.5) | .80 |
| (B1, B4) | 2/3 | 88.7 | (83.4–92.6) | 80.6 | (73.4–85.8) | 85.2 | (79.1–89.7) | 0.90 | (84.1–95.1) | .77 | (69.8–82.4) | .90 |
| (B1, B5) | 1/2 | 97.9 | (93.9–99.4) | 76.4 | (70.9–78.4) | 88.8 | (84.1–90.5) | 0.93 | (88.4–97.2) | .84 | (78.4–87.6) | .86 |
| (B2, B3) | 0/1 | 94.8 | (90.2–97.6) | 81.9 | (75.7–85.6) | 89.3 | (84.1–92.5) | 0.92 | (87.8–96.9) | .79 | (72.8–84.2) | .73 |
| (B2, B4) | 2/3 | 86.6 | (81.5–90.2) | 87.5 | (80.6–92.4) | 87.0 | (81.1–91.1) | 0.93 | (88.5–97.1) | .82 | (75.9–86.1) | .79 |
| (B2, B5) | 1/2 | 91.8 | (87.1–94.8) | 88.9 | (82.6–93.1) | 90.5 | (85.2–94.1) | 0.94 | (90.4–98) | .86 | (81.6–89.5) | .82 |
| (B3, B4) | 1/2 | 95.9 | (91.3–98.3) | 76.4 | (70.2–79.6) | 87.6 | (82.3–90.3) | 0.89 | (83.4–94.5) | .75 | (67–80.6) | .81 |
| (B3, B5) | 1/2 | 93.8 | (89.2–96.7) | 86.1 | (79.9–90) | 90.5 | (85.3–93.9) | 0.91 | (86.3–96.3) | .80 | (73.7–84.8) | .82 |
| (B4, B5) | 3/4 | 79.4 | (74.1–83) | 88.9 | (81.8–93.8) | 83.4 | (77.4–87.6) | 0.91 | (85.8–95.6) | .81 | (74.6–85.3) | .91 |
| Three-item version | ||||||||||||
| (B1, B2, B3) | 1/2 | 95.9 | (91.4–98.3) | 81.9 | (76–85.2) | 89.9 | (84.9–92.7) | 0.94 | (89.4–97.9) | .82 | (76–86.2) | .85 |
| (B1, B2, B4) | 3/4 | 89.7 | (84.7–93.2) | 86.1 | (79.4–90.9) | 88.2 | (82.4–92.2) | 0.93 | (88.7–97.4) | .82 | (76.5–86.5) | .89 |
| (B1, B2, B5) | 2/3 | 94.8 | (90.4–97.5) | 86.1 | (80.1–89.7) | 91.1 | (86–94.2) | 0.95 | (91–98.5) | .86 | (81.7–89.6) | .88 |
| (B1, B3, B4) | 2/3 | 93.8 | (89–96.9) | 79.2 | (72.7–83.3) | 87.6 | (82–91.1) | 0.91 | (85.6–95.8) | .78 | (71–83.1) | .89 |
| (B1, B3, B5) | 2/3 | 92.8 | (88.0–96.0) | 83.3 | (76.8–87.7) | 88.8 | (83.2–92.4) | 0.93 | (88.5–97.4) | .82 | (76.6–86.6) | .88 |
| (B1, B4, B5) | 4/5 | 84.5 | (79.3–88.4) | 86.1 | (79–91.3) | 85.2 | (79.1–89.6) | 0.92 | (87.3–96.5) | .82 | (76.2–86.3) | .92 |
| (B2, B3, B4) | 2/3 | 94.8 | (90.3–97.6) | 83.3 | (77.2–87) | 89.9 | (84.7–93.1) | 0.93 | (87.9–97) | .81 | (75.6–85.9) | .84 |
| (B2, B3, B5) | 1/2 | 95.9 | (91.5–98.2) | 84.7 | (78.9–87.9) | 91.1 | (86.1–93.8) | 0.93 | (89.1–97.6) | .85 | (79.8–88.5) | .85 |
| (B2, B4, B5) | 2/3 | 95.9 | (91.4–98.3) | 80.6 | (74.5–83.8) | 89.3 | (84.2–92.1) | 0.93 | (89.4–97.5) | .85 | (80–88.6) | .89 |
| (B3, B4, B5) | 3/4 | 86.6 | (81.5–90.2) | 87.5 | (80.6–92.4) | 87.0 | (81.1–91.1) | 0.91 | (86.2–96.1) | .80 | (74.4–85.2) | .89 |
Bold numbers indicate values of the best candidate for the 2- or 3-item scale. PDS, Posttraumatic Diagnostic Scale; PTSD, posttraumatic stress disorder; DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, 4th ed.; SN, sensitivity; SP, specificity; AUC, area under the curve.