Objective: To determine the durability of methicillin-resistant Staphylococcus aureus (MRSA)-free status after patients are removed from contact precautions and the association of specific clearance policy variables with survival.
Design: Retrospective cohort study from October 2007 to April 2013.
Setting: Veteran Affairs Boston Healthcare System.
Participants: Patients with a prior history of MRSA who were removed from contact precautions after deemed cleared of their MRSA status by infection prevention.
Methods: Active nasal screening results and clinical data from acute, long-term, and outpatient care facilities were evaluated to determine survival of MRSA-free status in a time-to-event analysis.
Results: A total of 351 unique patients were followed for 107,112 patient-days. The median age was 68 years. Overall, 249 (71%) of patients remained MRSA-free, and 102 (29%) reverted to MRSA positive. The median MRSA-free survival was 880 days. Comorbidities, presence of indwelling devices, and the use of systemic antibiotics at the time of clearance screening were not associated with MRSA-free survival. More than 21,000 days of inpatient isolation days were avoided during the study period.
Conclusions: The majority of patients removed from contact precautions remained MRSA-free for more than 2 years. Antibiotic use at the time of clearance was not associated with reductions in MRSA-free survival. These findings can be used to simplify clearance criteria, promote clearance policies, and reduce patient isolation days.