Performance of the Charlson and Elixhauser Comorbidity Index Varies With the Type of Minimally Invasive Thoracic Surgery.

Background: The Elixhauser (ECI) and Charlson-Deyo (CCI) comorbidity indices are two well-established measures used for assessing clinical prognosis and adjusting comorbidities in research. However, the optimal index is unclear within thoracic surgery. This study comparatively evaluates their effectiveness in predicting short-term outcomes (in-hospital mortality, complications, nonroutine discharge, and 30-/90-day readmissions) in minimally invasive pulmonary lobectomy (MIL) and minimally invasive Ivor Lewis esophagectomy (MIE).

Methods: Using the Healthcare Cost and Utilization Project National Readmission Database (2016-2018), MIL and MIE were identified using International Classification of Diseases, 10th Edition codes. Multivariable logistic regression models were constructed. The discriminative ability was quantified using the area under the receiver operating characteristic curve (AUC). The acceptable discriminative ability was defined as AUC > 0.70.

Results: CCI better predicted mortality (AUC 0.7866; 95% CI, 0.7549-0.8182) compared to ECI (AUC 0.7561; 95% CI, 0.7214-0.7908, p = 0.003) for MIL. The CCI marginally predicted nonroutine discharge (AUC 0.6427; 95% CI, 0.6362-0.6492 vs. ECI AUC 0.6399; 95% CI, 0.6333-0.6464, p = 0.01). In the MIE cohort, both the indices predicted mortality well (ECI 0.8038; 95% CI 0.7458-0.8618 vs. CCI 0.7969; 95% CI 0.7393-0.8546, p = 0.67). Neither index had acceptable discriminative ability for other outcomes.

Conclusions: Based upon two commonly performed index thoracic procedures, the outcomes may differ by comorbidity measure employed and by surgery type, suggesting the need for careful selection of index, especially once patients are deemed fit for surgery. The CCI is superior in predicting mortality in patients with MIL. Both CCI and ECI are suitable for MIE. Furthermore, with the recent implementation of an updated ECI incorporating ICD-10 coding, these findings support the durability and robustness of the new ECI. Future research investigating their performances in predicting long-term outcomes in thoracic surgery may be warranted.