Developing an early screening instrument for predicting psychological morbidity after critical illness

Introduction: Guidelines recommend follow-up for patients after an intensive care unit (ICU) stay. Methods for identifying patients with psychological problems after intensive care would be of value, to optimize treatment and to improve adequate resource allocation in ICU follow-up of ICU survivors. The aim of the study was to develop a predictive screening instrument, for use at ICU discharge, to identify patients at risk for post-traumatic stress, anxiety or depression. Methods: Twenty-one potential risk factors for psychological problems - patient characteristics and ICU-related variables - were prospectively collected at ICU discharge. Two months after ICU discharge 252 ICU survivors received the questionnaires Post-Traumatic Stress Symptom scale -10 (PTSS-10) and Hospital Anxiety and Depression Scale (HADS) to estimate the degree of post-traumatic stress, anxiety and depression. Results: Of the 150 responders, 46 patients (31%) had adverse psychological outcome, defined as PTSS-10 >35 and/or HADS subscales >= 8. After analysis, six predictors were included in the screening instrument: major pre-existing disease, being a parent to children younger than 18 years of age, previous psychological problems, in-ICU agitation, being unemployed or on sick-leave at ICU admission and appearing depressed in the ICU. The total risk score was related to the probability for adverse psychological outcome in the individual patient. The predictive accuracy of the screening instrument, as assessed with area under the receiver operating characteristic curve, was 0.77. When categorizing patients in three risk probability groups - low (0 to 29%), moderate (30 to 59%) high risk (60 to 100%), the actual prevalence of adverse psychological outcome in respective groups was 12%, 50% and 63%. Conclusion: The screening instrument developed in this study may aid ICU clinicians in identifying patients at risk for adverse psychological outcome two months after critical illness. Prior to wider clinical use, external validation is needed.