Screening and control of methicillin-resistant Staphylococcus aureus in 186 intensive care units: different situations and individual solutions

Table 6 Results of the multivariable analysis for ICU-acquired MRSA cases of 91 ICUs performing targeted screening

ICU structure and process parameters	IRR (95% CI)	P value^a
Type of ICU
Medical-surgical ICU	1 = reference	< 0.001
Medical ICU	0.32 (0.17-0.59)
Surgical ICU	1.31 (0.80-2.16)
Other ICU	0.45 (0.11-1.79)
Incidence of imported MRSA cases
Incidence of imported cases not greater than the median	1 = reference	< 0.001
Incidence of imported cases greater than the median	2.63 (1.69-4.00)
Length of stay
Length of stay not greater than the median	1 = reference	0.041
Length of stay greater than the median	1.58 (1.02-2.47)
Not significant in the multivariable analysis
Isolation (strict SR isolation/SR or contact precautions/contact precautions)
Decolonization with mupirocin (decolonization of all/not all MRSA patients)
Interaction: isolation-decolonization
Pre-emptive isolation
Short admissions of less than 48 hours of less than 1/3 of admitted patients
Nurse-to-patient ratio (not greater than the median/greater than the median)
Percentage of ventilator beds (not greater than the median/greater than the median)
Number and percentage of SRs (not greater than the median/greater than the median)
Size of hospital and ICU (not greater than the median/greater than the median)
Type of hospital (university/academic/other)
Device use (CVC, ventilation) (not greater than the median/greater than the median)

In the generalized linear regression model, the negative binomial distribution was used and the log number of patient-days was treated as an offset parameter. A stepwise forward approach was applied, and the selection criteria were the highest chi-square value and^aP value of less than 0.05 in the type III score chi-square statistic. CI, confidence interval; CVC, central venous catheter; ICU, intensive care unit; IRR, incidence rate ratio; MRSA, methicillin-resistant Staphylococcus aureus; SR, single room.

ISSN: 1364-8535