Antimicrobial Prescribing in Nursing Homes in Northern Ireland Results of Two Point-Prevalence Surveys Pamela McClean, Michael Tunney, Deirdre Gilpin, Carole Parsons and Carmel Hughes School of Pharmacy, Queen’s University Belfast, Belfast, UK Abstract Background: In 2005, the European Commission recommended that all member states should establish or strengthen surveillance systems for moni- toring the use of antimicrobial agents. There is no evidence in the literature of any surveillance studies having been specifically conducted in nursing homes (NHs) in Northern Ireland (NI). Objective: The aim of this study was to determine the prevalence of anti- microbial prescribing and its relationship with certain factors (e.g. indwelling urinary catheterization, urinary incontinence, disorientation, etc.) in NH re- sidents in NI. Methods: This project was carried out in NI as part of a wider European study under the protocols of the European Surveillance of Antimicrobial Con- sumption group. Two point-prevalence surveys (PPSs) were conducted in 30 NHs in April and November 2009. Data were obtained from nursing notes, medication administration records and staff in relation to antimicrobial prescribing, facility and resident characteristics and were analysed descriptively. Results: The point prevalence of antimicrobial prescribing was 13.2% in April 2009 and 10.7% in November 2009, with a 10-fold difference existing between the NHs with the highest and lowest antimicrobial prescribing prevalence during both PPSs. The same NH had the highest rate of antimicrobial pre- scribing during both April (30.6%) and November (26.0%). The group of antimicrobials most commonly prescribed was the penicillins (April 28.6%, November 27.5%) whilst the most prevalent individual antimicrobial pre- scribed was trimethoprim (April 21.3%, November 24.3%). The majority of antimicrobials were prescribed for the purpose of preventing urinary tract infections (UTIs) in both April (37.8%) and in November (46.7%), with 5% of all participating residents being prescribed an antimicrobial for this reason. Some (20%) antimicrobials were prescribed at inappropriate doses, partic- ularly those which were used for the purpose of preventing UTIs. Indwelling urinary catheterization and wounds were significant risk factors for anti- microbial use in April [odds ratio {OR} (95% CI) 2.0 (1.1, 3.5) and 1.8 (1.1, 3.0), respectively] but not in November 2009 [OR (95% CI) 1.6 (0.8, 3.2) and ORIGINAL RESEARCH ARTICLE Drugs Aging 2011; 28 (10): 819-829 1170-229X/11/0010-0819/$49.95/0 ª 2011 Adis Data Information BV. All rights reserved.