OBJECTIVES: To compare the 6- and 12-month outcomes of patients who recovered from subsyndromal delirium (SSD) by 8 weeks with the outcomes of patients who did not recover or did not have an index episode.
DESIGN: Secondary analysis of data collected for a cohort study of the prognosis of delirium.
SETTING: University-affiliated primary acute care hospital.
PARTICIPANTS: Older medical inpatients with prevalent, incident, or no SSD were classified into three mutually exclusive groups at 8 weeks (SSD-recovered, SSD-not recovered, no SSD) and followed up at 6 and 12 months.
MEASUREMENTS: The primary hierarchical composite outcome was death, institutionalization, or cognitive or functional decline at 6 and 12 months. In secondary analyses, components of the primary outcome were examined separately.
RESULTS: Of the 129 patients assessed at 8 weeks, 51, 47, and 31 met criteria for SSD-recovered, SSD-not recovered and no SSD, respectively. At 6 and 12 months, the primary and secondary outcomes of the SSD-recovered group were better than the outcomes of the SSD-not recovered group and, for the most part, intermediate between the outcomes of the SSD-not recovered and no SSD groups.
CONCLUSION: Recovery from SSD appears to predict better longer-term outcomes than no recovery. Efforts to identify and treat SSD in older medical inpatients may improve outcomes.