A novel risk classification system for 30-day mortality in children undergoing surgery

<div><p>A simple, objective and accurate way of grouping children undergoing surgery into clinically relevant risk groups is needed. The purpose of this study, is to develop and validate a preoperative risk classification system for postsurgical 30-day mortality for children undergoing a wide variety of operations. The National Surgical Quality Improvement Project-Pediatric participant use file data for calendar years 2012–2014 was analyzed to determine preoperative variables most associated with death within 30 days of operation (D30). Risk groups were created using classification tree analysis based on these preoperative variables. The resulting risk groups were validated using 2015 data, and applied to neonates and higher risk CPT codes to determine validity in high-risk subpopulations. A five-level risk classification was found to be most accurate. The preoperative need for ventilation, oxygen support, inotropic support, sepsis, the need for emergent surgery and a do not resuscitate order defined non-overlapping groups with observed rates of D30 that vary from 0.075% (Very Low Risk) to 38.6% (Very High Risk). When CPT codes where death was never observed are eliminated or when the system is applied to neonates, the groupings remained predictive of death in an ordinal manner.</p></div

Preoperative therapy and risk for death after surgery.

<p>Preoperative therapy and risk for death after surgery.</p

Observed mortality by risk group for sub groups.

<p>The observed mortality is plotted logarithmically by group. A = Very Low, B = Moderately Low, C = Moderately High, D = High, E = Very High. Each bar represents the estimate of the risk and confidence interval. The arrow is the observed rate for all patients from 2012–2015.</p

Comorbidities and risk for death after surgery.

<p>Comorbidities and risk for death after surgery.</p

Parsimonious LR model built on variables selected by classification tree analysis.

<p>Parsimonious LR model built on variables selected by classification tree analysis.</p

Surgical mortality risk groups for children.

<p>Surgical mortality risk groups for children.</p

Patient characteristics and risk for death after surgery.

<p>Patient characteristics and risk for death after surgery.</p

Characteristics of 1,186 patients diagnosed with metastatic colorectal cancer by group (diagnosis before or after July 1, 2008).

<p>Characteristics of 1,186 patients diagnosed with metastatic colorectal cancer by group (diagnosis before or after July 1, 2008).</p

Overall survival in the pre-testing (solid line) and post-testing (dashed line) groups.

<p>Overall survival in the pre-testing (solid line) and post-testing (dashed line) groups.</p

Sensitivity analysis showing unadjusted non-inferiority test results for overall survival (OS) using different dates to specify pre- and post-testing groups for adoption of KRAS testing.

1<p>Difference in months = Post-testing - Pre-testing; CB: one sided 95% lower confidence bound (LCB). If LCB>−5.0 months, then the post-testing OS is not worse than the pre-testing OS.</p>2<p>Unadjusted p-value for testing inferiority of OS in post- vs. pre-testing group.</p