Clinical predictors for severe sepsis in patients with necrotizing fasciitis: an observational cohort study in northern Thailand Patcharin Khamnuan,1,2 Wilaiwan Chongruksut,3 Kijja Jearwattanakanok,4 Jayanton Patumanond,5 Apichat Tantraworasin,3 1Clinical Epidemiology Program, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; 2Department of Nursing, Phayao Hospital, Phayao, Thailand; 3Department of Surgery, Faculty of Medicine, Chiang Mai University, 4Department of Surgery, Nakornping Hospital, Chiang Mai, Thailand; 5Clinical Epidemiology Unit, Clinical Research Center, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand Background: Necrotizing fasciitis (NF) is a life-threatening infection of skin and fascia. Its progress is extremely fast, with extensive necrosis. Delay in treatment, with subsequent huge soft tissue loss and associated severe sepsis, remains a major cause of death in the management of NF. Objective: The aim of this study was to explore clinical characteristics that may be used to predict severe sepsis in patients with NF, in the context of routine clinical practice in northern Thailand. Methods: A retrospective observational cohort study was conducted. The patient cohort in this study consisted of all patients who were diagnosed with NF by surgical or pathological confirmation. The follow-up period started with the admission date and ended with the discharge date. The clinical variables were collected from patients registered at three provincial hospitals in northern Thailand from 2009 to 2012. The clinical predictors for severe sepsis were analyzed using multivariable risk regression. Results: A total of 1,452 patients were diagnosed with NF, either with severe sepsis