Table 2.
Multilevel regression summary for nurse staffing and in-hospital mortality in cardiac surgery patients (n = 9054).
| Model 1 | Model 2 | Model 3 | |
|---|---|---|---|
| Intercept | −7.355 (<0.0001) | −6.849 (<0.0001) | −4.198 (<0.0001) |
| Procedural volume | 0.0004 (0.2185) | ||
| Nursing intensity: ICU | −0.415 (0.5820) | −1.246 (0.0032) | |
| Nursing intensity: general nursing units | 0.576 (0.4434) | 0.424 (0.2824) | |
| Male | −0.291 (0.0456) | −0.295 (0.0429) | −0.284 (0.0472) |
| Age | 0.036 (<0.0001) | 0.036 (<0.0001) | 0.037 (<0.0001) |
| APR-DRG 163 | −0.162 (0.5166) | −0.163 (0.5154) | −0.114 (0.6304) |
| APR-DRG 165 | −0.033 (0.8938) | −0.031 (0.8997) | −0.065 (0.7922) |
| APR-DRG 166 | −0.354 (0.1562) | −0.355 (0.1552) | −0.348 (0.1427) |
| ROM 2 | −0.072 (0.9157) | −0.074 (0.9144) | −0.113 (0.8660) |
| ROM 3 | 2.048 (0.0002) | 2.038 (0.0002) | 1.903 (0.0004) |
| ROM 4 | 5.240 (<0.0001) | 5.230 (<0.0001) | 4.974 (<0.0001) |
| NHPPD of general units | −1.227 (0.0448) | −1.342 (0.0475) | −1.395 (<0.0001) |
| Proportion of RNs with BSN on general units | −2.164 (0.0012) |
Model 1: adjustment for patient characteristics; model 2: adjustment for patient characteristics and nursing intensity; model 3: adjustment for patient characteristics, nursing intensity, and hospital characteristics; APR-DRG: All-Patient Refined Diagnosis Related Groups; ROM: Risk of Mortality; NHPPD = nursing hours per patient day; Proportion RNs with BSN = proportion of registered nurses with at least a bachelor’s degree; ICU = intensive care unit. The results of NHPPD of ICUs and Proportion of RNs with BSN in ICUs are not shown in the table because these explanatory variables were non-significant.