Introduction The intensive care environment can, along with the of- ten severe underlying disease process, confer an ex- treme physical and mental stress on patients and anxi- ety, pain, respiratory distress or nightmares are often re- ported by survivors of intensive care [1, 2, 3]. In a re- cently completed retrospective study in patients after prolonged intensive care therapy [4], such traumatic memories from the intensive care unit (ICU) were asso- ciated with serious impairments in psychosocial aspects of health-related quality of life and a high prevalence of post-traumatic stress disorder (PTSD). The occur- rence of PTSD in patients after ICU treatment has also C. Stoll H.P. Kapfhammer H. B. Rothenhäusler M. Haller J. Briegel M. Schmidt T. Krauseneck K. Durst G. Schelling Sensitivity and specificity of a screening test to document traumatic experiences and to diagnose post-traumatic stress disorder in ARDS patients after intensive care treatment Received: 23 November 1998 Final revision received: 18 March 1999 Accepted: 3 May 1999 This study was supported by a grant from the E. Lilly International Foundation C. Stoll ( ) ) ´ M. Haller ´ J. Briegel ´ T.Krauseneck ´ K. Durst ´ G. Schelling Dept. of Anaesthesiology, Klinikum Grosshadern, Ludwig-Maximilians University, D-81 377 Munich, Germany e-mail: c.stollmd@lrz.uni-muenchen.de Tel.: + 49-89-7 09 51 Fax: + 49-89-70 95 28 22 H. P.Kapfhammer ´ H.B. Rothenhäusler ´ T.Krauseneck Dept. of Psychiatry, Ludwig-Maximilians University, D-81 377 Munich, Germany M. Schmidt Institute for Medical Informatics, Biometrics and Epidemiology, Ludwig-Maximilians University, D-81 377 Munich, Germany Abstract Objective: Many survivors of critical illness and intensive care unit (ICU) treatment have traumat- ic memories such as nightmares, panic or pain which can be associat- ed with the development of post- traumatic stress disorder (PTSD). In order to simplify the rapid and early detection of PTSD in such patients, we modified an existing question- naire for diagnosis of PTSD and validated the instrument in a cohort of ARDS patients after long-term ICU therapy. Design: Follow-up cohort study. Setting: The 20-bed ICU of a univer- sity teaching hospital. Patients: A cohort of 52 long-term survivors of the acute respiratory distress syndrome (ARDS). Interventions and measurements: The questionnaire was administered to the study cohort at two time points 2 years apart. At the second evaluation, the patients underwent a structured interview with two trained psychiatrists to diagnose PTSD according to Diagnostic and Statistical Manual of Mental Disor- ders, 4th edition (DSM-IV) criteria. The reliability and validity of the questionnaire was then estimated and its specificity, sensitivity and optimal decision threshold deter- mined using receiver operating characteristic (ROC) curve analy- ses. Results: The questionnaire showed a high internal consistency (Crohn- bach's a = 0.93) and a high test-re- test reliability (intraclass correlation coefficient a = 0.89). There was evi- dence of construct validity by a lin- ear relationship between scores and the number of traumatic memories from the ICU the patients described (Spearman's r = 0.48, p < 0.01). Cri- terion validity was demonstrated by ROC curve analyses resulting in a sensitivity of 77.0 % and a specificity of 97.5 % for the diagnosis of PTSD. Conclusions: The questionnaire was found to be a responsive, valid and reliable instrument to screen survi- vors of intensive care for PTSD. Key words Intensive care ´ Post- traumatic stress disorder ´ Questionnaire ´ Recall ´ Memory ´ Outcome Intensive Care Med (1999) 25: 697±704 Ó Springer-Verlag 1999 ORIGINAL