Veteran Administration researchers www.research.va.gov are developing a new tool known as the Computerized-Adaptive Test (CAT) to assess symptoms of PTSD. The tool uses a computer algorithm to adapt questions in real time based on the patient’s answers to the previous items.
The use of this tool is very valuable, since an estimated 14 percent of Iraq and Afghanistan veterans have PTSD while about 10 to 12 percent of Gulf War Veterans and 30 percent of Vietnam veterans are affected.
Accurate assessment of PTSD is crucial for prescribing treatment and to monitor progress. The adaptive algorithms at the root of CATs allow researchers to accurately assess health status with high sensitivity and accuracy
The CAT works by first asking a base question selected for its high information value. The software than uses the patient’s response to choose the next question to elicit the most discriminating information.
The progression of questions is different for each patient and are designed to assess the four key domains of PTSD symptoms as defined in the “Diagnostic and Statistical Manual for Mental Health” (DSM).
The researchers developed the new CAT by first asking 1,085 veterans to respond to 89 questions extracted or adapted from other PTSD tests. Next, they built a computer test that would cover the diagnostic criteria of PTSD as defined by the DSM.
The researchers studied the use of CAT by administering the prototype to 203 veterans. By comparing the results from other PTSD screening tools, the researchers were able to verify that the CAT was accurate and reliable although further testing was needed.
Patients in the trial used the PTSD CAT on a tablet but the test can be taken on a smartphone or on other devices. The CAT can also be administered over a secure internet portal such as VA’s MyhealtheVet www.myhealthva.gov.
Researchers and authors working with the VA in the CAT study were from:
- Center for Healthcare Organization and Implementation Research at the Edith Nourse Rogers Memorial Veterans Hospital www.bedford.va.gov in Bedford Massachusetts
- Massachusetts Veterans Epidemiology Research and Information Center at the VA Boston Health Care System www.boston.va.gov
- Center for Chronic Disease Outcomes Research at the Minneapolis VA Health Care System www.minneapolis.va.gov
- Authors with Boston University www.bu.edu and the University of Massachusetts www.umass.edu