Comorbidity Status and Annual Total Medical Expenditures in U.S. Hypertensive Adults

INTRODUCTION: The purpose of this study is to investigate comorbidity status and its impact on total medical expenditures in non-institutionalized hypertensive adults in the U.S. METHODS: Data from the 2011–2014 Medical Expenditure Panel Survey were used. Patients were included if they had a diagnosis code for hypertension, were aged ≥18 years, and were not pregnant during the study period (N=26,049). The Elixhauser Comorbidity Index was modified to add hypertension-related comorbidities. The outcome variable was annual total medical expenditures, and a generalized linear model regression (gamma distribution with a log link function) was used. All costs were adjusted to 2014 U.S. dollars. RESULTS: Based on the modified Elixhauser Comorbidity Index, 14.0% of patients did not have any comorbidities, 23.0% had one, 24.4% had two, and 38.7% had three or more. The five most frequent comorbidities were hyperlipidemia, diabetes, rheumatoid arthritis, depression, and chronic pulmonary disease. Estimated mean annual total medical expenditures were $3,914 (95% CI= $3,456, $4,372) for those without any comorbidity; $5,798 (95% CI=$5,384, $6,213) for those with one comorbidity; $8,333 (95% CI=$7,821, $8,844) for those with two comorbidities; and $13,920 (95% CI=$13,166, $14,674) for those with three or more comorbidities. Of the 15 most frequent comorbidities, the condition with the largest impact on expenditures for an individual person was congestive heart failure ($7,380). Hypertensive adults with stroke, coronary heart disease, diabetes, renal diseases, and hyperlipidemia had expenditures that were $6,069, $6,046, $5,039, $4,974, and $4,851 higher, respectively, than those without these conditions. CONCLUSIONS: Comorbidities are highly prevalent among hypertensive adults, and this study shows that each comorbidity significantly increases annual total medical expenditures.