Classification of MRSA cases detected at the time of hospital admission: does the 'look-back' period matter?

Abstract

Limited resources for infection control necessitate efficient local surveillance. Cases of meticillin-resistant Staphylococcus aureus from the authors' hospital surveillance system were examined to determine if attribution of cases as healthcare-associated or non-healthcare-associated differed when using a 12-month vs a four-week 'look-back' period. Two additional cases were reclassified from non-healthcare-associated to healthcare-associated, representing a 2% reclassification rate between four-week and 12-month criteria (P = 0.857). Infection control programmes may save time and resources by minimizing retrospective review of records without compromising data quality due to misclassification.