Table 2.
Hazard Ratios for Primary and Secondary Trial Outcomes.
| Variable | Hazard Ratio (95% CI) | Overall P Value | ||
|---|---|---|---|---|
| Group 1 | Group 2 | Group 3 | ||
| MRSA | ||||
| Clinical culture | ||||
| As-assigned analysis | ||||
| Unadjusted* | 0.92 (0.77–1.10) | 0.75 (0.63–0.89) | 0.63 (0.52–0.75) | 0.01 |
| Adjusted | 0.92 (0.77–1.10) | 0.74 (0.62–0.88) | 0.64 (0.53–0.77) | 0.02 |
| As-treated analysis, unadjusted | 0.93 (0.78–1.11) | 0.78 (0.65–0.94) | 0.63 (0.52–0.75) | 0.01 |
| Randomization to all three groups, unadjusted analysis† | 0.93 (0.76–1.13) | 0.74 (0.62–0.89) | 0.63 (0.52–0.75) | 0.02 |
| Randomization strata accounted for, unadjusted analysis | 0.93 (0.78–1.11) | 0.75 (0.63–0.89) | 0.63 (0.52–0.75) | 0.01 |
| Mixed medical and surgical ICUs only, unadjusted analysis | 0.93 (0.76–1.12) | 0.71 (0.59–0.86) | 0.57 (0.46–0.71) | 0.004 |
| Bloodstream infection | ||||
| As-assigned analysis | ||||
| Unadjusted | 1.23 (0.82–1.85) | 1.23 (0.80–1.90) | 0.72 (0.48–1.08) | 0.11 |
| Adjusted | 1.20 (0.80–1.81) | 1.19 (0.77–1.84) | 0.74 (0.49–1.12) | 0.18 |
| As-treated analysis, unadjusted | 1.24 (0.82–1.86) | 1.34 (0.84–2.15) | 0.72 (0.48–1.08) | 0.08 |
| Randomization to all three groups, unadjusted analysis† | 1.15 (0.74–1.79) | 1.18 (0.74–1.89) | 0.72 (0.48–1.08) | 0.19 |
| Randomization strata accounted for, unadjusted analysis | 1.24 (0.83–1.86) | 1.22 (0.79–1.88) | 0.73 (0.48–1.09) | 0.12 |
| Mixed medical and surgical ICUs only, unadjusted analysis | 1.15 (0.75–1.77) | 1.20 (0.75–1.93) | 0.72 (0.44–1.20) | 0.28 |
| Bloodstream infection from any pathogen | ||||
| As-assigned analysis | ||||
| Unadjusted‡ | 0.99 (0.84–1.16) | 0.78 (0.66–0.91) | 0.56 (0.49–0.65) | <0.001 |
| Adjusted | 0.98 (0.84–1.15) | 0.77 (0.65–0.90) | 0.55 (0.48–0.64) | <0.001 |
| As-treated analysis, unadjusted | 0.99 (0.84–1.16) | 0.78 (0.66–0.92) | 0.56 (0.49–0.65) | <0.001 |
| Randomization to all three groups, unadjusted analysis† | 0.93 (0.78–1.10) | 0.77 (0.65–0.91) | 0.56 (0.49–0.65) | <0.001 |
| Randomization strata accounted for, unadjusted analysis | 0.99 (0.84–1.16) | 0.78 (0.66–0.91) | 0.56 (0.49–0.65) | <0.001 |
| Mixed medical and surgical ICUs only, unadjusted analysis | 0.96 (0.81–1.13) | 0.80 (0.67–0.96) | 0.59 (0.50–0.69) | <0.001 |
*
P values in the pairwise analysis were as follows: P = 0.09 for the comparison of group 2 with group 1, P = 0.003 for the comparison of group 3 with group 1, and P = 0.16 for the comparison of group 3 with group 2.
†
This analysis excluded the five hospitals in states with laws requiring MRSA screening in the ICU.
‡
P values in the pairwise analysis were as follows: P = 0.04 for the comparison of group 2 with group 1, P<0.001 for the comparison of group 3 with group 1, and P = 0.003 for the comparison of group 3 with group 2.