TDDS-SF — Terminal Delirium-Related Distress Scale - Short Form

What this tool is and how to interpret its evidence

TDDS-SF is the 15-item short form of the Terminal Delirium-Related Distress Scale. It was created to reduce the burden of the original 24-item questionnaire while retaining its purpose: retrospective evaluation of distress and care associated with irreversible terminal delirium. Bereaved relatives complete the form after the death of a family member with cancer who received hospice or specialist palliative care. Four broad domains concern care for the family, the patient's ability to communicate, psychiatric symptoms, and information or discussion about treatment. This page deliberately does not reproduce the questions or response anchors; the primary paper contains the authoritative form and scoring information.

The developers removed weakly loading original items, obtained palliative-care expert review and evaluated the resulting form in 366 bereaved family members who reported that their relative had experienced delirium. Factor analysis supported the four-domain structure. Correlations with the Care Evaluation Scale and Good Death Inventory supported convergent validity, while the weaker association with bereaved-family distress supported distinction between related constructs. Reported internal-consistency coefficients ranged from 0.70 to 0.94 across scales.

TDDS-SF is a version of TDDS, not another independent delirium family. It does not detect delirium, grade current patient severity or prescribe management. Its evidence is currently centred on Japanese bereavement research in cancer palliative care; prospective use with patients or families during an episode and broader cross-cultural validation require separate study.