Patient selection: surgical patient
Outcome: surgical site infection
Risk factors for surgical site infection:
(1) advanced age
(2) frailty and increasing dependence
(3) comorbidities (see below)
(4) surgical complexity and/or duration
(5) wound class (clean to dirty)
(6) use of a medical device (foreign body)
(7) failure to use appropriate antibiotic prophylaxis
(8) colonization for Staphylococcus aureus (treatment might reduce the risk)
Comorbidities:
(1) diabetes mellitus
(2) obesity (higher body mass index)
(3) smoking and/or COPD
(4) heart disease (heart failure, coronary artery disease, etc)
(5) renal insufficiency
Other factors may include:
(1) longer preoperative length of hospital stay (>= 8 days)
Risk indices associated with an increased risk:
(1) NNIS (based on ASA class, duration of surgery and wound class)
(2) ASA class (comorbidities and severity of illness)
(3) Charlson comorbidity index
Detection of SSI's depends on adequacy of follow-up. Median time to SSI onset was 17 days, with longer intervals seen tumor-related, orthopedic and transplant surgeries.