Hospital Inpatient Cost And Discharge Status Of Diabetes And Its Complications In The U.S.

Abstract

Diabetes is a huge economic and clinical burden to the health care system in the U.S. However, the incremental effect of diabetes complications has not been well documented in the literature. In addition, diabetes-related hospitalization discharge status has not been thoroughly examined. This study was carried out with two objectives: the primary objective of this study was to examine the association between the presence and severity of diabetes-related complications and diabetes-related hospitalization costs and discharge status. The secondary objective of this study was to explore how the presence and type of diabetes influenced complications-related hospitalization costs and discharge status. This study was a cross-sectional study with secondary data analysis of the 2010 to 2012 National Inpatient Sample (NIS). The study sample consisted of four disease cohorts: diabetes-related hospitalization cohort, peripheral lower-extremity (PLE) diseases-related hospitalization cohort, kidney diseases-related hospitalization cohort, and coronary atherosclerosis-related hospitalization cohort. In each cohort, hospitalization cost was calculated by multiplication of the total hospitalization charge by the cost-to-charge ratio. Hospitalization discharge status was dichotomized as routine discharge and non-routine discharge. Two statistical models were fit: a generalized linear model with gamma distribution and log link was used for modeling hospital inpatient cost; multivariate logistic regression was adopted for modeling hospitalization discharge status. The covariates in the regression model included complications and other variables identified by the Andersen’s behavioral model of health service utilization. The diabetes-related hospitalization contained 804,192 discharge records. The incremental cost of severe PLE was approximately $6,849. Severe PLE and less severe PLE increased diabetes-related hospitalization cost by 66.6% and 1.35% respectively. Comorbid kidney diseases were not found to be associated with an apparent increase in diabetes-related hospitalization cost. The incremental cost of severe coronary atherosclerosis was approximately $1,200. Severe PLE was also associated with increased odds of having non-routine discharges after hospitalization. The final peripheral lower extremity (PLE) diseases-related hospitalization cohort contained 219,752 discharge records. The presence of type 1 diabetes was associated with a 12% decrease in PLE-related hospitalization cost, while the presence of type 2 diabetes was associated with a 3.85% decrease in PLE-related hospitalization cost. The association between diabetes and PLE-related hospitalization cost was modified by age. PLE-related hospitalization cost was highest among patients younger than 65 years and without diabetes ($17,075). Diabetes was also significantly associated with hospitalization discharge status. PLE patients with diabetes were 1.37 times more likely to have a non-routine discharge compared to PLE patients without diabetes. The presence of type 2 diabetes was associated with even greater odds (a 26.2% increase) of having non-routine discharges. The final cohort of kidney diseases-related hospitalization contained 504,320 discharge records. The association between diabetes and kidney diseases-related hospitalization cost was also modified by age. The incremental cost of type 1 diabetes to kidney diseases-related hospitalization was $922 for patient below 65 years and $1,320 for patient age 65 years or older. Among patients below 65 years, the kidney diseases hospitalization cost for patients with type 2 diabetes was $785 lower than that for patients without diabetes. However, among patients age 65 years or older, the cost for patients with type 2 diabetes was only $84 lower than the patients without diabetes. The presence of type 1 diabetes was associated with a 33.2% increase in the odds of having non-routine discharges; while the presence of type 2 diabetes was associated with a 20.2% increase in the odds of having non-routine discharges. The coronary atherosclerosis-related hospitalization cohort contained 546,488 discharge records. The association between diabetes and coronary-atherosclerosis related hospitalization cost was also modified by age. The incremental cost of type 1 diabetes was $1,796 among hospitalized coronary atherosclerosis patients age 65 years or older, while the cost for patients with type 1 diabetes comorbidity was $550 lower than patients without diabetes among those age below 65 years. Type 1 diabetes was associated with a 35.4% increase in the odds of having non-routine discharges, while type 2 diabetes did not have any significant effect on coronary atherosclerosis-related hospitalization discharge status. In sum, this study found that severe peripheral lower-extremity diseases and severe coronary atherosclerosis are associated with significant increases in diabetes-related hospitalization cost. In addition, severe PLE was also associated with increased likelihood of having non-routine discharges after diabetes-related hospitalization. The impact between diabetes and complications-related hospitalization cost varies by age group and diabetes type. Among patients with PLE-related hospitalization, cost was highest among patients age <65 years and without comorbid diabetes. In the kidney diseases-related hospitalization cohort, cost was highest for patients younger than 65 years and also had comorbid type 1 diabetes. Among patients with coronary atherosclerosis-related hospitalization, cost was highest for patients 65 years and older and who had type 1 diabetes comorbidity. Both type 1 and type 2 diabetes are associated with higher odds of having non-routine discharges after complications-related hospitalization. The findings of this study highlighted the importance of peripheral lower extremity diseases as a driver of diabetes-related hospitalization cost. Optimal diabetes disease management programs should be adopted nationwide to reduce the incidence and prevalence of diabetes complications and improve the overall population health.