Development of a Risk Stratification Scoring System to Predict General Surgical Complications for Patients Undergoing Foot and Ankle Surgery

Preventing postoperative complications is crucial for patients, surgeons, and health care facilities. We developed a risk stratification scoring system to optimize postoperative outcomes for patients undergoing foot and ankle surgery. A total of 35,580 patients who underwent foot and ankle procedures from 2005 to 2017 were identified as part of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP). To assess the risk of a postoperative complication, we identified several independent risk factors associated with 30-day postoperative complications, then proceeded to develop a point-based risk scoring system. To validate our scoring system, we used it on a cohort of patients from the database who underwent foot and ankle surgery. Risk factors that correlated with postoperative complications included tobacco abuse, age (≥65 years), diabetes mellitus, hypertension, elevated creatinine level (≥1.3 mg/dL), hypoalbuminemia (<3.5 g/dL), chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), hyponatremia (<135 mEq/L), and anemia (hematocrit value, men <42%; women <38%). Point scores for each factor were: anemia, +10; hypoalbuminemia, +9; elevated creatinine level, +6; CHF, +4; diabetes mellitus, +3; hyponatremia, +3; COPD, +2; hypertension, +2; age, +1; and tobacco abuse, +1. For the validation cohort, we stratified patients according to risk as low (0-20 points), medium (21-30 points), and high (≥31 points) risk. In terms of having a postoperative complication, compared with low-risk patients, patients who were at medium risk had an odds ratio of 4.7 (95% CI, 2.8-7.9) and those at high risk had an odds ratio of 8.3 (95% CI, 4.8-14.5).