Validity of a New Administrative Measure of Psychiatric Severity in a Prospective Sample of Veterans Applying for PTSD Disability Benefits: The Manifestations of Psychiatric Severity Index (MoPSI)

Background: Administrative data help managers monitor and manage health care enrollees’ health. Of the few available administrative measures of psychiatric illness severity, however, most either commingle sociodemographics and medical comorbidities or lack ordinal properties. Objective: To assess construct, concurrent, and predictive validity of a novel, 6-item, administrative measure of psychiatric severity, the Manifestations of Psychiatric Severity Index (MoPSI). Methods: A panel study of 960 gender-stratified, nationally representative, post-9/11 US Veterans with pending disability claims for posttraumatic stress disorder (PTSD). MoPSI scoring was based on the joint probability density (JPD) method and a JPD linear approximation. Results: The JPD MoPSI score and its linear approximated score had a correlation of 0.999. Relative to their counterparts, unmarried Veterans, Veterans with low income, and Veterans with serious mental illness or PTSD had higher MoPSI scores (Ps: <0.0001–0.03). Higher MoPSI scores predicted cigarette and street drug use and PTSD and depression/anxiety symptoms six months later, and disability award approximately 1 year later (Ps: 0.01–0.02). Conclusions: In this sample, the MoPSI had evidence of construct, concurrent, and predictive validity.