A New Perspective on the Evaluation of Comorbidity Indices on Survival in Non-Small Cell Lung Cancer

Abstract

Objective: Mortality studies are interpreted by considering comorbid diseases related to the main disease. Existence, number, and type of comorbid diseases can have an important effect on prognosis. There are various comorbidity indices to include the effects of comorbid diseases in the model. With a new perspective, we aimed to emphasize the importance of evaluating the combination of comorbid diseases in cancer survival. Methods: Retrospective cohort, data were collected from cases with Non-Small Cell Lung Cancer treated in Department of Chest Diseases. Initially, the effects of their comorbid diseases on the duration of survival were calculated with univariate analysis, then examined according to number of comorbidities, lastly their specific combinations' Hazar Ratio were calculated with Cox multivariate analysis. The most used comorbid indices in the literature were also included. Results: Out of 247 non-small cell lung cancer (NSCLC) cases analysis, 220 (89%) were men. Median duration of follow-up was 277 days, at the end of the follow-up 197 cases had died. HR of two comorbid diseases in cases was 1.80, but 59.52 for the combination of “diabetes and interstitial lung disease” and 3.76 for “diabetes and previously cancer”. Existing comorbid indices had no significant effect on survival time (p:0.684; 0.101; 0.273; 0.567, respectively). Conclusion: We have offered a new perspective which takes into comorbid diseases related to main disease and specially their combinations when the risk is estimated in survival research. Accurate assessments of the list of comorbid diseases related to main disease hold significant importance in advancing this field.