Risk factors for prolonged treatment and hospital readmission in 280 cases of negative-pressure wound therapy

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. (C) 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.