Predictive accuracy of 29-comorbidity index for in-hospital deaths in US adult hospitalizations with a diagnosis of venous thromboembolism

Background: Venous thromboembolism (VTE), the collective term for deep vein thrombosis (DVT) and pulmonary embolism (PE), is a significant source of mortality, morbidity, and impaired health-related quality of life worldwide. This study evaluated the predictive accuracy of the Agency for Healthcare Research and Quality (AHRQ)'s 29-comorbidity index for in-hospital death in US adult hospitalizations with a diagnosis of VTE.

Method: We analyzed data from the 2010 Nationwide Inpatient Sample developed by the AHRQ. We calculated the case-fatality and prevalence of comorbidities in a sample of 153,518 adult hospitalizations with a diagnosis of VTE. We estimated adjusted odds ratios (aOR) and 95% confidence intervals with multivariate logistic regression models by using comorbidities as predictors and status of in-hospital death as an outcome variable. We assessed c-statistics for the predictive accuracy of regression models.

Results: Of the estimated adult hospitalizations with a diagnosis of DVT (N=440,151), PE (N=329,986), or VTE (N=770,137), there were approximately 20,212, 21,732, and 41,944 in-hospital deaths in 2010, respectively. When compared to DVT, PE, or VTE subgroups without the corresponding comorbidities, congestive heart failure, chronic pulmonary disease, coagulopathy, liver disease, lymphoma, fluid and electrolyte disorders, metastatic cancer, other neurological disorders, peripheral vascular disorders, pulmonary circulation disorders, renal failure, solid tumor without metastasis, and weight loss were positively and independently associated with 1.16-2.25 times increased likelihoods of in-hospital death. The c-statistic values ranged from 0.794 to 0.802.

Conclusion: The AHRQ 29-comorbidity index provides acceptable to excellent predictive accuracy for in-hospital deaths in adult hospitalizations with DVT, PE, or VTE overall.