title: A prospective observational cohort study in primary care practices to identify factors associated with treatment failure in Staphylococcus aureus skin and soft tissue infections.
abstract: BACKGROUND
  The incidence of outpatient visits for skin and soft tissue infections (SSTIs) has substantially increased over the last decade. The emergence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has made the management of S. aureus SSTIs complex and challenging. The objective of this study was to identify risk factors contributing to treatment failures associated with community-associated S. aureus skin and soft tissue infections SSTIs.
  
  
  METHODS
  This was a prospective, observational study among 14 primary care clinics within the South Texas Ambulatory Research Network. The primary outcome was treatment failure within 90 days of the initial visit. Univariate associations between the explanatory variables and treatment failure were examined. A generalized linear mixed-effect model was developed to identify independent risk factors associated with treatment failure.
  
  
  RESULTS
  Overall, 21% (22/106) patients with S. aureus SSTIs experienced treatment failure. The occurrence of treatment failure was similar among patients with methicillin-resistant S. aureus and those with methicillin-susceptible S. aureus SSTIs (19 vs. 24%; p = 0.70). Independent predictors of treatment failure among cases with S. aureus SSTIs was a duration of infection of ≥7 days prior to initial visit [aOR, 6.02 (95% CI 1.74-19.61)] and a lesion diameter size ≥5 cm [5.25 (1.58-17.20)].
  
  
  CONCLUSIONS
  Predictors for treatment failure included a duration of infection for ≥7 days prior to the initial visit and a wound diameter of ≥5 cm. A heightened awareness of these risk factors could help direct targeted interventions in high-risk populations.
authors.affiliation: College of Pharmacy, University of Texas at Austin, Austin, TX, USA. leeg3@uthscsa.edu.|Pharmacotherapy Education and Research Center, School of Medicine, The University of Texas Health Science Center, 7703 Floyd Curl Dr, MC 6220, San Antonio, TX, 78229-3900, USA. leeg3@uthscsa.edu.
authors.forename: Grace C
authors.initials: GC
authors.lastname: Lee
authors.affiliation: School of Pharmacy, Texas Tech University Health Sciences Center, Dallas, TX, USA.|Dose Optimization and Outcomes Research (DOOR) Program, Dallas, TX, USA.
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Hall
authors.affiliation: College of Pharmacy, University of Texas at Austin, Austin, TX, USA.|Pharmacotherapy Education and Research Center, School of Medicine, The University of Texas Health Science Center, 7703 Floyd Curl Dr, MC 6220, San Antonio, TX, 78229-3900, USA.
authors.forename: Natalie K
authors.initials: NK
authors.lastname: Boyd
authors.affiliation: Department of Clinical Laboratory Sciences, School of Health Professions, University of Texas Health Science Center, San Antonio, TX, USA.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Dallas
authors.affiliation: South Texas Ambulatory Research Network, The University of Texas Health Science Center, San Antonio, TX, USA.
authors.forename: Liem C
authors.initials: LC
authors.lastname: Du
authors.affiliation: South Texas Ambulatory Research Network, The University of Texas Health Science Center, San Antonio, TX, USA.
authors.forename: Lucina B
authors.initials: LB
authors.lastname: Treviño
authors.affiliation: South Texas Ambulatory Research Network, The University of Texas Health Science Center, San Antonio, TX, USA.
authors.forename: Sylvia B
authors.initials: SB
authors.lastname: Treviño
authors.affiliation: South Texas Ambulatory Research Network, The University of Texas Health Science Center, San Antonio, TX, USA.
authors.forename: Chad
authors.initials: C
authors.lastname: Retzloff
authors.affiliation: College of Pharmacy, University of Texas at Austin, Austin, TX, USA.
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Lawson
authors.affiliation: College of Pharmacy, University of Texas at Austin, Austin, TX, USA.
authors.forename: James
authors.initials: J
authors.lastname: Wilson
authors.affiliation: Department of Pathology and Genomic Medicine, Houston Methodist Hospital and Research Institute, Houston, TX, USA.
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Olsen
authors.affiliation: Department of Biology, The University of Texas San Antonio, San Antonio, TX, USA.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Pharmacy, University of Texas at Austin, Austin, TX, USA.|Pharmacotherapy Education and Research Center, School of Medicine, The University of Texas Health Science Center, 7703 Floyd Curl Dr, MC 6220, San Antonio, TX, 78229-3900, USA.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Frei
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000502:physiology; D011446:Prospective Studies; D018461:Soft Tissue Infections / Q000188:drug therapy* / Q000382:microbiology; D013207:Staphylococcal Skin Infections / Q000188:drug therapy* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors; D017211:Treatment Failure; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents
keywords: Epidemiology; Methicillin-resistant Staphylococcus aureus (MRSA); Primary care; Skin and soft tissue infections; Staphylococcus aureus