Table I. Risk of MRSA infection with colonization.
| Characteristic | 2000-2001 | 2006-2007 | Both periods |
|---|---|---|---|
| Patients tested | 810 | 925 | 1735 |
| Patients colonized | 5 | 27 | 32 |
| Patients not colonized | 805 | 898 | 1703 |
| Patients infected and colonized | 5 | 13 | 18 |
| Patients infected but not colonized | 3 | 22 | 25 |
| RR of infectiona | 268.3 | 19.7 | 38.3 |
| 95% CI | 86.72 - 830.24 | 11.13 - 34.71 | 23.36 - 62.84 |
| Characteristic | 2000-2001 | 2006-2007 | p-value |
| Prevalence of colonizationb | 0.62% (5/810) | 2.92% (27/925) | 0.0003 |
| Prevalence of infectionc | 0.99% (8/810) | 3.78% (35/925) | 0.0002 |
MRSA, methicillin-resistant Staphylococcus aureus; RR, relative risk; CI, confidence interval;
a
Relative risk of infection is the ratio of risk of infection occurring in patients with colonization versus patients without colonization;
b
Prevalence of colonization is the proportion of patients with MRSA colonization among all admitted patients who were screened for MRSA in that time period;
c
Prevalence of infection is the proportion of patients diagnosed with MRSA infection either at or during admission among all patients admitted to the hospital and screened for MRSA in that time period.