Risk factors and recommendations for rate stratification for surveillance of neonatal healthcare-associated bloodstream infection A. Holmes a,d ,C.J.Dore´ c , A. Saraswatula b , K.B. Bamford a,d , M.S. Richards d , R. Coello a,d , N. Modi b,e, * a Division of Investigative Sciences, Imperial College London, UK b Division of Medicine, Imperial College London, UK c Medical Research Council Clinical Trials Unit, London, UK d Department of Infectious Diseases and Microbiology, Hammersmith Hospitals NHS Trust, London, UK e Department of Neonatal Medicine, Chelsea & Westminster Hospital, London, UK Received 24 January 2007; accepted 23 August 2007 Available online 17 October 2007 KEYWORDS Infant newborn; Bloodstream infection; Surveillance; Risk factors; Risk stratification Summary Neonates are among the most vulnerable patient groups for healthcare-associated infection with multiple endogenous and exogenous risks. Interpretation of neonatal bloodstream infection (BSI) rates re- quires stratification for case-mix. We assessed 1367 consecutive admis- sions to a single neonatal unit over a 34-month period. Four intrinsic and seven extrinsic risks were evaluated using Poisson regression analyses both individually and in combination. Nine of the 11 evaluated risk fac- tors were significantly associated with BSI on univariate analyses. The only significant independent risks were parenteral nutrition, whether administered centrally or peripherally [incidence rate ratio (IRR): 14.2; 95% confidence interval (CI): 8.8e22.9; P < 0.001], and gestational age <26 weeks (IRR: 2.5; 95% CI: 1.7e3.8; P < 0.001). The rate of BSI per 1000 patient-days was 40 times higher in infants with both of these than in infants with neither. If validated in other settings, stratification of neonatal BSI rate by two unambiguous risk factors, parenteral nutrition * Corresponding author. Address: Imperial College London, Division of Medicine, 369 Fulham Road, London SW10 9NH, UK. Tel.: þ44 20 8237 5102; fax: þ44 20 8746 8050. E-mail address: n.modi@imperial.ac.uk 0195-6701/$ - see front matter ª 2007 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jhin.2007.08.019 Journal of Hospital Infection (2008) 68, 66e72 Available online at www.sciencedirect.com www.elsevierhealth.com/journals/jhin