Evaluation of the impact of an antimicrobial stewardship program initiative in patients with uncomplicated acute bacterial skin and skin structure infections

Background. Acute bacterial skin and skin structure infections (ABSSSIs) are often associated with unnecessary use of broad-spectrum antibiotics, extended treatment durations and prolonged hospitalizations. An Antimicrobial Stewardship Program (ASP) ABSSSI initiative was implemented in August 2015 at Allegheny General Hospital and Western Pennsylvania Hospital. Methods. A retrospective chart review was conducted for uncomplicated ABSSSI patients admitted between 1 August 2014 and 31 March 2015 for the pre-intervention group and 1 August 2015 and 31 March 2016 for the post-intervention group. Outcomes assessed included: patient demographics, length of stay (LOS), site of infection, treatment duration, spectrum of antimicrobial coverage, imaging utilization, microbiologic cultures and 30-day readmission rates. Results. A total of 165 patients with uncomplicated ABSSSIs were included. When compared with the pre-intervention group, mean + SD duration of therapy decreased (12.6 ± 3.8 days versus 8.9 ± 2.2 days; p < 0.001) and appropriate duration of less than 10 days occurred in more patients (67.9% versus 20.2%; p < 0.001). Fewer patients were exposed to broad spectrum antimicrobial therapy with Gram-negative (44.8% versus 9.7%; p < 0.001), anti-pseudomonal (17.2% versus 1.8%; p < 0.001) and anaerobic (39.9% versus 10.3%; p < 0.001) coverage. Mean + SD LOS decreased from 3.7 ± 2.6 days to 2.2 ± 1.3 days (p < 0.001). A non-significant reduction was seen in all-cause 30 day readmission (7.4% versus 4.8%, p = 0.366) and recurrent infection 30 day readmission (3.5% versus 1.8%, p = 0.217) rates. The most common pathogen isolated in wound cultures was Staphylococcus aureus (49.4%), with 56% methicillin- resistant (MRSA) and 44% methicillin-susceptible (MSSA). There was no difference seen in utilization of imaging: CT 17.8% versus 12.7%, p = 0.37; MRI 8% versus 4.8%, p = 0.27; x-ray 57.1% versus 49.7%, p = 0.19; and blood cultures (77.9% versus 73.9%, p = 0.44). ASP made recommendations in 125 patients with a 96% acceptance rate. Conclusion. We illustrated the positive impact of implementing an ASP initiative in patients with ABSSSIs on appropriate selection and duration of antibiotic therapy, LOS and 30 day readmission rates.