Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. Hospital admission among HIV-exposed uninfected children compared with HIV-unexposed children Ellen Moseholm a , Marie Helleberg b , Sannie B. Nordly c , Vibeke Rosenfeldt c , Merete Storgaard d , Gitte Pedersen e , Isik S. Johansen f , Suzanne Lunding g , Nina Weis a and Terese L. Katzenstein b Objective: : The main objective of this study was, on a national level, to investigate the risk of in-hospital admissions and use of antibiotics during the first 4 years of life among HIV-exposed uninfected (HEU) children compared with a matched control group of HIV-unexposed children. Design: A nationwide register-based cohort study. Methods: All HEU children born in Denmark from 2000 to 2012 were individually matched to five HIV-unexposed controls. Outcomes were risk of hospital admission (any, because of an infectious disease, observation/nonspecific diagnosis) and use of antibiotics during the first 4 years of life. Incidence rate ratios (IRRs) were estimated using Poisson regression analysis. Results: In total, 317 HEU children and 1581 matched controls were included. HEU children had a three-fold increased risk of overall admissions {incidence rate ratio (IRR) 3.49 [95% confidence interval (CI) 2.98–4.08]}. There was no difference in risk of admission because of infectious diseases [IRR 1.11 (95% CI 0.73–1.70)] and no difference in use of antibiotics [IRR 0.88 (95% CI 0.73–1.04)]. The excess risk per 100 person-years of admission was primarily caused by an increased risk of admission because of observation/nonspecific diagnosis [excess incidence rate 22.6 (95% CI 18.2–27.0), IRR 6.06 (95% CI 4.84–7.61)]. Conclusion: HEU children had an increased risk of overall hospital admission mainly due to an increased risk of admission because of observation/nonspecific diagnosis. There was no increased risk of admission due to infectious disease. The excess risk of admission among HEU may be related to prophylactic treatment and/or HIV testing rather than somatic disease related to HIV or exposure to antiretroviral therapy. Copyright ß 2016 Wolters Kluwer Health, Inc. All rights reserved. AIDS 2016, 30:2697–2706 Keywords: admission to hospital, children, HIV-exposed uninfected, morbidity, national cohort study a Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, b Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, c Department of Pediatrics, Copenhagen University Hospital, Hvidovre, d Department of Infectious Diseases, Aarhus University Hospital, Skejby, e Department of Infectious Diseases, Aalborg University Hospital, f Department of Infectious Diseases, Odense University Hospital, and g Department of Pulmonary and Infectious Diseases, Copenhagen University Hospital, Nordsjælland, Denmark. Correspondence to Ellen Moseholm, Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Kettega ˚rd Alle ´ 30, Department 144, 2650 Hvidovre, Denmark. Tel: +0045 26702548; e-mail: elar0073@regionh.dk Received: 13 April 2016; revised: 27 June 2016; accepted: 8 July 2016. DOI:10.1097/QAD.0000000000001230 ISSN 0269-9370 Copyright Q 2016 Wolters Kluwer Health, Inc. All rights reserved. 2697