title: Risk factors for prolonged treatment and hospital readmission in 280 cases of negative-pressure wound therapy.
abstract: BACKGROUND
  There is evidence of certain beneficial effects and increasing understanding of the mechanisms of action of negative-pressure wound therapy (NPWT). However, it is known that prolonged duration of NPWT is associated with increased bacterial growth and efforts should be made to decrease the duration of NPWT. It was the aim of this study to evaluate potential risk factors for the duration, from first application of NPWT to secondary wound closure and to identify factors that increase the rate of hospital readmission.
  
  
  METHODS
  In a retrospective cohort study, 261 patients (46 ± 19 years, 70 female) who underwent 280 treatments with NPWT were analysed. Patient-specific and demographic characteristics and the presence of several risk factors were documented. The duration of treatment from first application of NPWT to secondary wound closure, the number of interventions, the duration of hospital stay and the incidence of readmissions due to complications of the wound treated by NPWT were recorded and a risk factor analysis was performed.
  
  
  RESULTS
  The median number of NPWT procedures was 2.0 ± 2.0, the duration of NPWT was 6.0 ± 14.7 days and the length of hospital stay was 16.0 ± 27.9 days. Presence of an open fracture (p = .002) and increased age (p = .004) were identified as independent risk factors for a prolonged duration of NPWT. Patients who smoked (p = .001) or patients with alcohol/drug abuse (p = .015) were more likely to return to hospital (smoking: 18 out of 58 cases; alcohol/drug abuse: 7 out of 19 cases). No such association was seen for diabetes (p = .702), peripheral vascular disease (PVD) (p = .052), immunosuppressive medication (p = .187), immunodeficiency (p = .404), trauma (p = .358), infection (p = .298) and open fracture (p = .061).
  
  
  CONCLUSIONS
  Patient age and presence of an open fracture are independent predictors of a prolonged duration from first application of NPWT to secondary wound closure. These results should be taken into account for the calculation of average costs and anticipated hospital stay associated with this therapy.
authors: Division of Trauma Surgery, University of Zurich, Raemistrasse 100, 8091 Zurich, Switzerland. Electronic address: georg.osterhoff@usz.ch.
authors: Georg
authors: G
authors: Osterhoff
authors: Division of Trauma Surgery, University of Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
authors: Pawel
authors: P
authors: Zwolak
authors: Division of Trauma Surgery, University of Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
authors: Carmen
authors: C
authors: Krüger
authors: Division of Trauma Surgery, University of Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
authors: Verena
authors: V
authors: Wilzeck
authors: Division of Trauma Surgery, University of Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
authors: Hans-Peter
authors: HP
authors: Simmen
authors: Division of Trauma Surgery, University of Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
authors: Gerrolt N
authors: GN
authors: Jukema
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D019973:Alcohol-Related Disorders / Q000150:complications; D005260:Female; D005597:Fractures, Open / Q000150:complications*; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D054843:Negative-Pressure Wound Therapy / Q000009:adverse effects*; D010359:Patient Readmission; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D013997:Time Factors; D055815:Young Adult
keywords: Negative-pressure wound therapy; Open fractures; Risk factors; Vacuum-assisted closure; Wound healing