Table 5.
Cut Points for Predictive Probabilities of PTSD Case Status and Estimated Misclassification Rates in the VHA and MVP Cohorts
| Cohort | Prob. (case) cut-off | Cases (n) | Est. mis.a (%) | Est. mis.b (%) | Sea | Seb | Spa | Spb | PPVa | PPVb | NPVa | NPVb |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| VHAc | Lasso | 1,166,962 | 23.9 | 6.4 | .99 | .78 | .96 | .99 | .83 | .93 | 1.0 | .95 |
| > 0.6 | 933,249 | 17.3 | 4.2 | .99 | .74 | .97 | .99 | .89 | .96 | 1.0 | .95 | |
| > 0.7 | 762,225 | 8.7 | 0.6 | .99 | .71 | .99 | 1.0 | .95 | .99 | 1.0 | .94 | |
| > 0.8 | 690,599 | 8.5 | 0.7 | .99 | .69 | .99 | 1.0 | .96 | .99 | 1.0 | .94 | |
| MVPd | Lasso | 22,651 | 18.2 | 5.7 | .98 | .98 | .92 | .97 | .73 | .89 | 1.0 | 1.0 |
| > 0.6 | 19,058 | 12.9 | 1.4 | .98 | .98 | .95 | .99 | .81 | .97 | 1.0 | .99 | |
| > 0.7 | 16,490 | 9.2 | 1.5 | .98 | .97 | .97 | 1.0 | .87 | .98 | .99 | .99 | |
| > 0.8 | 15,416 | 9.6 | 1.6 | .98 | .97 | .97 | 1.0 | .87 | .98 | .99 | .99 | |
Note. VHA = Veterans Health Administration; MVP = Million Veteran Program; Prob. = probability; Est. mis. = estimated misclassification; Se = sensitivity; Sp = specificity; PPV = positive predictive value; NPV = negative predictive value.
a
Group possible PTSD + controls.
b
Group possible PTSD + cases.
c
Based on n = 6,163,430 controls.
d
Based on n = 46,884 controls.