Screening for HIV-related PTSD: Sensitivity and specificity of the 17-item Posttraumatic Stress Diagnostic Scale (PDS) in identifying HIV-related PTSD among a South African sample

Abstract

Objectives: The identification of HIV-positive patients who exhibit criteria for Post traumatic Stress Disorder (PTSD) and related trauma symptomatology is of clinical importance in the maintenance of their overall wellbeing. This study assessed the sensitivity and specificity of the 17-item Post traumatic Stress Diagnostic Scale (PDS), a self-report instrument, in the detection of HIVrelated PTSD. An adapted version of the PTSD module of the Composite International Diagnostic Interview (CIDI) served as the gold standard. Method: 85 HIV-positive patients diagnosed with HIV within the year preceding data collection were recruited by means of convenience sampling from three HIV clinics within primary health care facilities in the Boland region of South Africa. Results: A significant association was found between the 17-item PDS and the adapted PTSD module of the CIDI. A ROC curve analysis indicated that the 17-item PDS correctly discriminated between PTSD caseness and non-caseness 74.9% of the time. Moreover, a PDS cut-off point of ≥ 15 yielded adequate sensitivity (68%) and 1-specificity (65%). The 17-item PDS demonstrated a PPV of 76.0% and a NPV of 56.7%. Conclusion: The 17-item PDS can be used as a brief screening measure for the detection of HIV-related PTSD among HIV-positive patients in South Africa.

Key Words: ROC analysis; Posttraumatic Stress Diagnostic Scale (PDS); Composite International Diagnostic Interview (CIDI); South Africa