The impact of adverse events in the intensive care unit on hospital mortality and length of stay

Table 4 Effect of adverse events (AE) on patient outcomes.

a) Effect of AEs on time to death
Variable	Hazard ratio (95% CI)
Model 1
AE	0.93 (0.44–1.98)
Age	1.0 (0.98–1.02)
Probability of death	1.41 (1.24–1.60)
LOS prior to ICU admit	0.94 (0.86–1.02)
Charlson score	1.13 (0.96–1.32)
Model 2*
Preventable AE	0.72 (0.25–2.04)
Non-preventable AE	0.69 (0.27–1.76)
CI = Confidence interval.
b) Effect of AEs on time to discharge and length of stay
Variable	Hazard ratio (95% CI)
Model 1:
AE	0.50 (0.31–0.81)
Age	1.00 (0.99–1.01)
Probability of death	0.84 (0.78–0.91)
LOS prior to ICU admit	0.99 (0.96–1.02)
Charlson score	0.88 (0.77–1.00)
*Model 2:**
Preventable AE	0.46 (0.23–0.91)
Non-preventable AE	0.54 (0.30–1.00)
CI = Confidence interval.

These tables present the association of ICU-based adverse events (AEs) with time to death (section a) and time to hospital discharge (section b). For each outcome, two models are presented: in model 1 we modelled time to first AE as the independent variable of interest; in model 2 we modelled time to first preventable AE and non-preventable AEs as the independent variables of interest. In all models, adverse events were expressed as time-dependent factors. All models were stratified by patient location prior to ICU admission. For brevity, we omitted the hazard ratios for these covariates for Model 2 from the table as they do not differ from the estimates presented for Model 1. The hazard ratio for probability of death represents the increase in risk expected with a 10% increase in the new Simplified Acute Physiology Score [7].

ISSN: 1472-6963