SCDI — Strain of Care for Delirium Index

What this tool is and how to interpret its evidence

The Strain of Care for Delirium Index (SCDI) measures nurses' perceived difficulty and strain when caring for people who display delirium-related behaviours. It is a workforce and care-process research measure, not a patient delirium screen, severity scale or diagnostic instrument. The final SCDI contains 20 self-report items rated from 1, relatively easy to manage, to 4, very difficult to manage. Scores can therefore range from 20 to 80, with higher totals indicating greater perceived strain; no diagnostic or clinical intervention cutoff has been established.

Milisen and colleagues began with 38 candidate items. Expert content review reduced these to 28, which were completed by a convenience sample of 190 nurses. Nonlinear principal-components analysis removed another eight items and produced a 20-item, four-factor form explaining 61.51% of variance. The reported alpha of .88 applied to the 28-item field version before final reduction, so it should not be presented unqualified as reliability of the final form. Subsequent translations and ICU studies provide additional, version-specific psychometric support, including recent Korean confirmation of the four-factor structure.

The SCDI is most useful for studying staff burden, education, organisational support and changes after service interventions. It should not be scored from observations of a patient or used to decide whether delirium is present. The page can explain its scale structure and scoring direction without reproducing the questionnaire, and should link the original paper and later validation evidence separately.