A brief screening tool for assessing psychological trauma in clinical practice: development and validation of the New York PTSD Risk Score

Abstract

Objective: The objective was to develop a brief posttraumatic stress disorder (PTSD) screening instrument that is useful in clinical practice, similar to the Framingham Risk Score used in cardiovascular medicine.

Methods: We used data collected in New York City after the World Trade Center disaster (WTCD) and other trauma data to develop a new PTSD prediction tool--the New York PTSD Risk Score. We used diagnostic test methods to examine different clinical domains, including PTSD symptoms, trauma exposures, sleep disturbances, suicidal thoughts, depression symptoms, demographic factors and other measures to assess different PTSD prediction models.

Results: Using receiver operating curve (ROC) and bootstrap methods, five prediction domains, including core PTSD symptoms, sleep disturbance, access to care status, depression symptoms and trauma history, and five demographic variables, including gender, age, education, race and ethnicity, were identified. For the best prediction model, the area under the ROC curve (AUC) was 0.880 for the Primary Care PTSD Screen alone (specificity=82.2%, sensitivity=93.7%). Adding care status, sleep disturbance, depression and trauma exposure increased the AUC to 0.943 (specificity=85.7%, sensitivity=93.1%), a significant ROC improvement (P<.0001). Adding demographic variables increased the AUC to 0.945, which was not significant (P=.250). To externally validate these models, we applied the WTCD results to 705 pain patients treated at a multispecialty group practice and to 225 trauma patients treated at a Level I Trauma Center. These results validated those from the original WTCD development and validation samples.

Conclusion: The New York PTSD Risk Score is a multifactor prediction tool that includes the Primary Care PTSD Screen, depression symptoms, access to care, sleep disturbance, trauma history and demographic variables and appears to be effective in predicting PTSD among patients seen in healthcare settings. This prediction tool is simple to administer and appears to outperform other screening measures.

Fig. 1

Nomogram for PCPS with psychosocial predictors included. Fig. 1 shows scale metrics used in score development with the aid of a nomogram, whereby final regression coefficients are converted to additive risk scores relative the PCPS using a linear predictor associated with the probability of the outcome. Note that the variables “regdoc” and “traumcat1” are reversed (i.e., negatively weighted) and the values for each predictor variable in the nomogram correspond to those shown in Table 5 for column B. pcps=Primary Care PTSD Screen; phq2_1=one positive depression symptom on PHQ2 scale; phq2_2=two positive depression symptoms on PHQ2 scale; traumcat1=history of low trauma exposure (one event); traumcat2=history of moderate trauma exposure (two to three events); traumcat3=history of high trauma exposure (four+ events); prbslp1y=difficulty sleeping in past year; regdoc=has regular source of care/doctor. For an example of the use of a nomogram in clinical practice, see Kattan M.W., Wheeler T.M., Scardino P.T. Postoperative nomogram for disease recurrence after radical prostatectomy for prostate cancer. Journal of Clinical Oncology, 1999; 17: 1499–1507.