Table 2. Bivariate analysis of categorical variables potentially associated with acquiring a healthcare-associated infection (HAI) in 3 intensive care units and one step-down unit in Hospital das Clínicas, University of São Paulo, Brazil (May 2009–August 2009).

Variables	Patients who acquired HAI (n: 43)	Patients who did NOT acquire HAI (n: 152)	Relative risk	95% confidence interval	p
Male sex	23	76	1.12	0.66–1.89	0.69
Presence of comorbidity	34	109	1.52	0.75–3.05	0.23
Origin					0.93
• Hospital ward	8	31
• Emergency room	25	89
• Operating room	4	16
• Other	6	16
Excessive nursing workload (NAS≥51%)	40	116	3.33	1.09–10.21	0.016
Medical/hospital interventions
• Enteral nutrition	33	19	9.08	4.82–17.08	<0.001
• CVC	39	76	6.78	2.52–18.23	<0.001
• Mechanical ventilation	32	50	4.01	2.15–7.48	<0.001
• Urinary catheter	40	91	6.51	2.09–20.26	<0.001
• Transfusion	24	32	3.14	1.87–5.25	<0.001
• Hemodialysis	14	20	2.29	1.36–3.84	0.003
• Endoscopy	8	10	2.25	1.24–4.08	0.016
• Total parenteral nutrition	1	1	2.30	0.56–9.42	0.34
• Bronchoscopy	4	11	1.23	0.51–2.98	0.65
• Drains	3	10	1.05	0.38–2.94	0.93
• Surgery	7	24	1.03	0.50–2.10	0.94
Death during stay in the unit	17	23	2.53	1.53–4.19	<0.001
Death during hospital stay	19	29	2.42	1.46–4.02	<0.001
Occurrence of other adverse events during hospitalization
• Pressure ulcer	31	28	5.95	3.29–10.77	<0.001
• Cancellation of programmed surgery	3	1	3.58	1.91–6.72	0.01
• Hypoglicemia	15	27	1.95	1.15–3.30	0.016
• Phlebitis	11	26	1.47	0.82–2.63	0.21
• Delay >24 h of consults	8	21	1.31	0.68–2.53	0.44
• Hospitalization >24 h after discharge ordered	10	33	1.07	0.58–1.99	0.83
• Cancellation of invasive procedure	1	9	0.44	0.07–2.88	0.35

CVC: central venous catheter; NAS: Nursing activity score.