The development and initial validation of the Terminally Ill Grief or Depression Scale (TIGDS)

Patients often experience 'preparatory-grief' as they cope with the dying process. Some may be depressed. The Terminally Ill Grief or Depression Scale (TIGDS), comprising grief and depression sub-scales, is a new self-report measure designed to differentiate between preparatory-grief and depression in adult inpatients. The initial 100-item inventory was assembled based on literature review, interviews with clinicians and dying patients and then shortened to 42 items based on consensus expert opinion. Validity and reliability were tested in a sample of 55 terminally ill adults. The consensus clinical opinion was used as the gold standard to differentiate between preparatory grief and depression. The intra-class correlation coefficient was high (it was calculated to estimate the test-retest reliability for the 47 patients who had completed the TIGDS twice--retest was administered 2 to 7 days after the initial test), ranging from 0.86 (grief) to 0.97 (depression). The validity of TIGDS was assessed using a receiver operating characteristic curve analysis, comparing the first test with the clinical criterion. The first and only variable and cut-point was the depression score (chi-square = 18.4, p < 0.001, cut point = 3). The sensitivity of the TIGDS was 0.727 and specificity was 0.886 for the depression = 3 cutoff score. The construct validity of the TIGDS was tested by comparing with the Hospital Anxiety and Depression Scale (HADS). The TIGDS depression subscale showed strong convergent validity and the TIGDS grief subscale showed strong discriminant validity with the HADS total score.