Table 1. Multivariable analysis of risk factors for VISA and hVISA infections, New York, New York, USA, 2002–2007*.
| Risk factor and MRSA strain | Odds ratio | Adjusted risk ratio (95% CI) | Adjusted risk difference (95% CI)† |
|---|---|---|---|
| Age‡ | |||
| VISA | 0.93 | 0.82 (0.65 to 1.12) | –0.020 (–0.080 to 0.007) |
| hVISA | 0.93 | 0.96 (0.73 to 1.35) | –0.003 (−0.050 to 0.013) |
| Race/ethnicity | |||
| Black | |||
| VISA | 0.90 | 0.76 (0.35 to 1.57) | –0.02 (–0.07 to 0.04) |
| hVISA | 0.90 | 1.03 (0.44 to 2.13) | 0.002 (−0.050 to 0.070) |
| Hispanic | |||
| VISA | 0.89 | 0.87 (0.36 to 1.88) | –0.01 (–0.06 to 0.05) |
| hVISA | 0.46 | 0.62 (0.19 to 1.37) | −0.03 (−0.08 to 0.03) |
| Asian | |||
| VISA | 1.97 | 1.79 (0.77 to 3.34) | 0.06 (−0.02 to 0.15) |
| hVISA | 1.58 | 1.65 (0.66 to 3.21) | 0.05 (−0.03 to 0.14) |
| Concurrent condition | |||
| Diabetes | |||
| VISA | 1.42 | 1.44 (0.78 to 2.59) | 0.03 (−0.02 to 0.08) |
| hVISA | 0.69 | 0.87 (0.48 to 1.48) | −0.01 (−0.05 to 0.03) |
| Chronic hemodialysis | |||
| VISA | 1.25 | 1.23 (0.56 to 2.57) | 0.02 (−0.04 to 0.09) |
| hVISA | 1.32 | 1.05 (0.48 to 2.03) | 0.004 (−0.040 to 0.060) |
| HIV | |||
| VISA | 0.50 | 0.45 (0.09 to 1.06) | –0.05 (−0.090 to 0.004) |
| hVISA | 0.30 | 0.27 (0.06 to 1.38) | −0.060 (−0.100 to −0.008) |
| Liver cirrhosis | |||
| VISA | 2.38 | 3.43 (2.02 to 6.00) | 0.14 (0.06 to 0.23) |
| hVISA | 2.55 | 2.11 (1.06 to 3.87) | 0.080 (0.005 to 0.170) |
| Malignancy | |||
| VISA | 2.02 | 1.96 (1.07 to 3.31) | 0.070 (0.005 to 0.130) |
| hVISA | 1.37 | 1.64 (0.87 to 3.07) | 0.04 (−0.01 to 0.11) |
| Other | |||
| Nursing home residence | |||
| VISA | 1.62 | 1.83 (0.88 to 3.30) | 0.060 (–0.009 to 0.130) |
| hVISA | 1.12 | 0.94 (0.36 to 1.80) | –0.005 (–0.060 to 0.050) |
| Surgical procedure§ | |||
| VISA | 0.50 | 0.41 (0.20 to 0.76) | –0.06 (–0.10 to –0.02) |
| hVISA | 0.79 | 0.62 (0.32 to 1.02) | –0.040 (–0.080 to 0.002) |
| Prior receipt of vancomycin | |||
| VISA | 1.87 | 2.09 (1.25 to 3.67) | 0.06 (0.02 to 0.10) |
| hVISA | 0.92 | 0.97 (0.56 to1.65) | −0.002 (−0.040 to 0.040) |
| Central venous catheter infection | |||
| VISA | 0.80 | 0.83 (0.50 to1.36) | –0.01 (–0.05 to 0.02) |
| hVISA | 2.09 | 1.81 (1.13 to 3.10) | 0.050 (0.009 to 0.090) |
*Results from logistic regression with outcomes and covariates. VISA, vancomycin-intermediate Staphylococcus aureus strains, hVISA, heteroresistant vancomycin-intermediate S. aureus strains; MRSA, methicillin-resistant S. aureus. †Adjusted risk difference refers to the absolute difference in risk; for example, an adjusted risk difference of 0.10 signifies a 10% increased risk for hVISA, VISA, given that variable. ‡Measures are adjusted odds ratio for a 10-y difference and adjusted risk difference for effect of age 50–60 y. §Surgical procedures under general anesthesia within the past 3 months.