Treatment failure and costs in patients with methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections: a South Texas Ambulatory Research Network (STARNet) study

Abstract

Objective: To measure the incidence of treatment failure and associated costs in patients with methicillin-resistant Staphylococcus aureus skin and soft tissue infections (SSTIs).

Methods: This was a prospective, observational study in 13 primary care clinics. Primary care providers collected clinical data, wound swabs, and 90-day follow-up information. Patients were considered to have "moderate or complicated" SSTIs if they had a lesion ≥5 cm in diameter or diabetes mellitus. Treatment failure was evaluated within 90 days of the initial visit. Cost estimates were obtained from federal sources.

Results: Overall, treatment failure occurred in 21% of patients (21 of 98) at a mean additional cost of $1,933.71 per patient. In a subgroup analysis of patients who received incision and drainage, those with moderate or complicated SSTIs had higher rates of treatment failure than those with mild or uncomplicated SSTIs (36% vs. 10%; P=.04).

Conclusions: One in 5 patients presenting to a primary care clinic for a methicillin-resistant S. aureus SSTI will likely require additional interventions at an associated cost of almost $2,000 per patient. Baseline risk stratification and new treatment approaches are needed to reduce treatment failures and costs in the primary care setting.

Keywords: Antibiotics; Cost of Illness; Epidemiology; Infectious Diseases; Practice-based Research; Primary Health Care.

Figure 1

MRSA SSTI Severity Classification and Qualifying Characteristics, n=98

Figure 2

Type of Treatment Failure *

Figure 3

Initial Antibiotic Choice, n=98

Figure 4

Proportion of Patients with Treatment Failure: Patients Receiving I&D, n=62