A novel nomogram accurately quantifies the risk of mortality in elderly patients undergoing colorectal surgery

The ability to accurately predict postoperative mortality is expected to improve preoperative decisions for elderly patients considered for colorectal surgery.

Patients undergoing colorectal surgery were identified from the National Surgical Quality Improvement Program database (2005-2007) and stratified as elderly (>70 years) and nonelderly (<70 years). Univariate analysis of preoperative risk factors and 30-day mortality and morbidity were analyzed on 70% of the population. A nomogram for mortality was created and tested on the remaining 30%.

Of 30,900 colorectal cases, 10,750 were elderly (>70 years). Mortality increased steadily with age (0.5% every 5 years) and at a faster rate (1.2% every 5 years) after 70 years, which defined "elderly" in this study. Elderly (mean age: 78.4 years) and nonelderly patients (52.8 years) had mortality of 7.6% versus 2.0% and a morbidity of 32.8% versus 25.7%, respectively. Elderly patients had greater preoperative comorbidities including chronic obstructive pulmonary disease (10.5% vs 3.8%), diabetes (18.7% vs 11.1%), and renal insufficiency (1.7% vs 1.3%). A multivariate model for 30-day mortality and nomogram were created. Increasing age was associated with mortality [age >70 years: odds ratio (OR) = 2.0 (95% confidence interval (CI): 1.7-2.4); >85 years: OR = 4.3 (95% CI: 3.3-5.5)]. The nomogram accurately predicted mortality, including very high-risk (>50% mortality) with a concordant index for this model of 0.89.

Colorectal surgery in elderly patients is associated with significantly higher mortality. This novel nomogram that predicts postoperative mortality may facilitate preoperative treatment decisions.