Validation of the Distress Thermometer, Impact Thermometer and combinations of these in screening for distress

Objective: Screening for distress is important for identifying those who might benefit from support and allocating limited resources. A common screening tool is the Distress Thermometer (DT) but other thermometers such as the Impact Thermometer (IT) have also been suggested. The objective of this study was to investigate the accuracy in identifying distress of these two screening thermometers individually and two possible methods of combining the responses. Methods: A random selection of 400 patients from a regional cancer treatment service data base was selected and 50% responded to a mailed questionnaire. The accuracy of these screening options individually and of two methods of combining the responses was investigated by comparison with responses to the Hospital Anxiety and Depression Scale. Results: The results supported the cut off suggested in the literature for the DT. The IT individually was found to perform at least as well as the DT individually. However, the combinations of the two generally proved to be more accurate than either used alone. Conclusions: These results suggest that the accuracy of the DT in identifying distress can be increased by combining it with the IT. This increase in accuracy must be weighed against the possible increase in complexity. However, one method of combining the responses from the two thermometers simply involves summing the two scores and this should not be enough to deter busy clinicians from screening patients and family members. Copyright © 2011 John Wiley & Sons, Ltd.