Waiting for the break of dawn? The effects of discharge time, discharge TISS scores and discharge facility on hospital mortality after intensive care.

OBJECTIVE: To assess the effects of discharge Therapeutic Intervention Scoring System (TISS) scores, discharge time and type of discharge facility on ultimate hospital mortality after intensive care.
DESIGN: Retrospective cohort study.
SETTING: General intensive care unit (ICU) in a district general hospital. PATIENTS AND PARTICIPANTS: One thousand six hundred fifty-four ICU patients discharged to hospital wards or high dependency units (HDUs). MAIN MEASUREMENTS AND
RESULTS: Vital status at ultimate hospital discharge was the main outcome measurement. The crude hospital mortality after ICU discharge (12.6%) was significantly associated with increasing discharge TISS scores (chi(2) for trend =9.0, p=0.028). This trend was similarly observed after adjusting for severity of disease. Patients with high TISS scores (>30) who were discharged to hospital wards had a higher risk (1.31; CI: 1.02-1.83) of in-hospital death compared with patients discharged to HDUs. Crude mortality was significantly higher for late 20.00 h to 7.59 h) than for early (8.00 h to 19.59 h) discharges (18.8% versus 11.2%, chi(2) =12.1, p=0.0004). Adjusted for disease severity, the mortality risk was 1.70-fold (CI: 1.28-2.25) increased for late ICU discharges. Patients discharged late to hospital wards had significantly higher severity-adjusted risks (1.87; CI:1.36-2.56) than had patients discharged to HDUs (1.35; CI: 0.77-2.36).
CONCLUSIONS: Both late discharge and high discharge TISS scores are indicators of "premature" ICU discharge and were associated with increased mortality. Intermediate care reduced the mortality of patients discharged "prematurely" from ICU. This adds to the growing evidence of the benefits of intermediate care after ICU discharge.