The distress thermometer (DT) is a useful measure of psychological distress in cancer patients. Our objective was to investigate distress impact on oncology patients in Turkey and determine the optimal cut-off score on the DT for identifying clinically significant distress. One hundred and eighty two cancer patients completed the DT, Problem List (PL), and Hospital Anxiety and Depression scale (HADS), The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30 version 3.0). The receiver operating characteristic (ROC) curve analyses of DT scores yielded an estimated area under the curve of 0.66 when compared to the HADS cut-off score, suggesting the DT is an effective scale to discriminate between classified cancer patients both with and without clinically significant distress. The DT cut-off score of 4 yielded the optimal combination of sensitivity and specificity. Scores on the DT were moderately correlated to the HADS (p<0.01) and EORTC QLQ-C30. Based on the significant correlations, we conclude that the DT has acceptable criterion validity. Copyright (c) 2006 John Wiley & Sons, Ltd.
