The aims of this study were to develop an evaluation scale to assess irreversible terminal delirium and to examine its validity.
We had interviews with health-care professionals engaged in treatment of terminally ill cancer patients to explore treatment goals in irreversible terminal delirium for patients and their families. Based on this qualitative analysis and systematic literature searches, we made a questionnaire and carried out a questionnaire survey regarding to views of bereaved families for treatment goals in terminal delirium. We extracted items which bereaved families regarded as important and tried to develop an evaluation scale of terminal delirium. Then, we conducted a cross-sectional, self-completed questionnaire survey for bereaved relatives of cancer patients who were admitted to a hospice or a palliative care unit.
We developed the Terminal Delirium Scale (TDS), a twenty-four items questionnaire consisting of six subscales (support for families and esteeming a patient highly, ability to communicate, no hallucination and delusion, adequate explanation of treatment and care for delirium and dying in a natural way, generally at peace and secured, not physically restrained or connected to tubes) Two hundred eighty-one bereaved relatives participated in the validation phase. Construct validity was shown to be good by repeated factor analysis. Convergent validity, confirmed by a correlation between TDS and Care Evaluation Scale（r=0.651, P<0.001）, was also good. The TDS had good internal consistency (Cronbach's alpha coefficient for all 24 items = 0.84).
This study indicates that the TDS is a valid and feasible measure of irreversible terminal delirium. We plan to reconsider this scale including assessment of irreversible terminal delirium by medical staffs.