title: Biofilm-forming bacteria and quality of life improvement after sinus surgery.
abstract: BACKGROUND
  It remains unclear how much chronic rhinosinusitis (CRS) patients with bacterial biofilms can benefit from functional endoscopic sinus surgery (FESS). We aimed to evaluate whether biofilm-forming bacteria was associated with quality of life (QOL) improvement after FESS.
  
  
  METHODS
  This retrospective cohort study included adult CRS patients who underwent FESS from 2008 to 2011. Sinus samples were taken to evaluate for biofilm-formation in vitro using a modified Calgary Biofilm Detection Assay. QOL was measured before FESS, and 1-month, 3-month, and 6-month after FESS using 22-item Sino-Nasal Outcome Test (SNOT-22) scores. Patients' characteristics and medications were collected. Clinical significant QOL change was defined as a difference of at least 0.5 standard deviation (SD) of baseline SNOT-22 score in the reference group.
  
  
  RESULTS
  A total of 156 patients had complete data, and 15% had biofilm-forming bacteria (n = 24). Patients with biofilm-forming bacteria had significantly worse preoperative SNOT-22 scores compared to patients without biofilm-forming bacteria (48 ± 20 vs 38 ± 23, p = 0.048). Both groups had clinically significant QOL improvement after FESS, and the differences in their 1-month (23 ± 19 vs 17 ± 20) and 3-month (27 ± 18 vs 18 ± 19) post-FESS SNOT-22 scores were not significant. However, patients with biofilm-forming bacteria demonstrated significantly less QOL improvement than patients without biofilm-forming bacteria from pre-FESS to 6-month post-FESS visits after adjusting for clinical factors (35 ± 25 vs 14 ± 15; β-coefficient = 0.71; 95% confidence interval [CI], 0.13 to 1.28; p = 0.016).
  
  
  CONCLUSIONS
  CRS patients with biofilm-forming bacteria demonstrated clinically significant QOL improvement following FESS, but the degree of improvement was decreased overtime and became significantly worse than patients without biofilm-forming bacteria by 6-month follow-up. This QOL worsening was independent of other risk factors for CRS.
authors.affiliation: Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA.
authors.forename: Zi
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA.
authors.forename: Nithin D
authors.initials: ND
authors.lastname: Adappa
authors.affiliation: Department of Surgery, University of Arizona, Tucson, AZ.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Chiu
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA.
authors.forename: Laurel J
authors.initials: LJ
authors.lastname: Doghramji
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA.|Philadelphia Veterans Affairs Medical Center, Philadelphia, PA.
authors.forename: Noam A
authors.initials: NA
authors.lastname: Cohen
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA.
authors.forename: James N
authors.initials: JN
authors.lastname: Palmer
mesh_terms: D000328:Adult; D018407:Bacterial Physiological Phenomena; D018441:Biofilms; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D059747:Nasal Surgical Procedures; D010256:Paranasal Sinuses / Q000601:surgery*; D011184:Postoperative Period; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification / Q000502:physiology; D011788:Quality of Life / Q000523:psychology*; D012189:Retrospective Studies; D012220:Rhinitis / Q000382:microbiology* / Q000523:psychology / Q000601:surgery; D012852:Sinusitis / Q000382:microbiology* / Q000523:psychology / Q000601:surgery; D013211:Staphylococcus aureus / Q000302:isolation & purification / Q000502:physiology; D013296:Streptococcus pneumoniae / Q000302:isolation & purification / Q000502:physiology
keywords: bacteria; biofilm; chronic rhinosinusitis; functional endoscopic sinus surgery; quality of life