2). This corresponds to an absolute increase in IP LOS of approximately 1.2 days (11.3 – 11.3/exp(.117) = 1.2). Table 2 Results of the multivariate models for NVPLDE225 hospital length of stay and total hospital cost IP Cost The fitted multivariate model for total hospital cost showed that admission-delayed patients have on average 11.0% (95% CI: 6.0% – 16.4%) higher IP cost compared to patients who were not delayed (p < .0001), adjusting for age, sex, ED triage urgency, arrival by ambulance, ICU admission, site of ED, and CMG (Table ​(Table2).2). This corresponds to an absolute difference Inhibitors,research,lifescience,medical in IP cost of approximately

$1216 (12,307-12,307/exp(.104) = 1216). Patients Admitted to ICU or Surgery We fitted multivariate regression models for IP LOS and IP cost using only those patients admitted to ICU or surgery (excluding CMG as a covariate). In both cases the ED TTD variable was not significant (p > 0.1). Cumulative Impact of Delay We estimated Inhibitors,research,lifescience,medical the cumulative impact of these delays on the study hospital. IP LOS was 11.3 days among delayed patients, and delay was associated with a 12.4%

increase in IP LOS. Thus, the cumulative impact of delay was 1558 patients × 11.3 days × 12.4% Inhibitors,research,lifescience,medical = 2183 additional hospital days. Using the 95% confidence intervals the excess hospital days due to admission delay could be as low as 6.6% (1162 days) or as high as 18.5% (3257 days). IP cost was $12,307 among delayed patients and delay was associated with an 11% increase in IP cost. Thus, the cumulative impact of delay was 1558 patients × $12,307 × 11% = $2,109,173, or approximately $1354 per admitted patient who experiences delay. Inhibitors,research,lifescience,medical The 95% confidence interval for increased costs ranges from $1,150,458 to $3,144,586. Discussion Inhibitors,research,lifescience,medical This is the first study that we know of to estimate the impact of delays to admission from the ED on inpatient hospital outcomes in Canada. In multivariate

analysis we found that patients who experienced admission delay in the ED had 12.4% nearly longer IP LOS and incurred 11.0% higher IP costs compared to patients who were not delayed. This association is important because approximately 11% of admissions from the ED experienced delay and the cumulative effects of these delays on cost and IP LOS can be substantial. Our analysis suggest that there may be a purely financial “business case” for investments that improve ED throughput and reduce delays. That is, there may be system-wide saving associated with investments targeted to improving ED throughput. In our sample the cumulative effect of delay for the 1558 patients who experienced delay was 2183 extra hospital days and $2,109,173 in additional hospital cost corresponding to approximately $1354 per admitted patient who experiences delay.