Liver disease is an important cause of morbidity and mortality in the United States. Geographic variations in the burden of chronic liver disease may have significant impact on public health policies but have not been explored at the national level. The objective of this study is to examine interstate variability in liver disease mortality in the United States.
Methods
We compared liver disease mortality from the 2010 National Vital Statistics Report on a state level. States in each quartile of liver disease mortality were compared with regard to viral hepatitis death rates, alcohol consumption, obesity, ethnic and racial composition, and household income. Race, ethnicity, and median household income data were derived from the 2010 US Census. Alcohol consumption and obesity data were obtained from the 2010 Behavioral Risk Factor Surveillance System Survey.
Results and Conclusion
We found significant interstate variability in liver disease mortality, ranging from 6.4 to 17.0 per 100,000. The South and the West carry some of the highest rates of liver disease mortality. In addition to viral hepatitis death rates, there is a strong correlation between higher percentage of Hispanic population and a state’s liver disease mortality rate (r = 0.538, P < .001). Lower household income (r = 0.405, P = .003) was also associated with the higher liver disease mortality. While there was a trend between higher obesity rates and higher liver disease mortality, the correlation was not strong and there was no clear association between alcohol consumption and liver disease mortality rates.
Introduction
While chronic liver disease is the 12th leading cause of death in all Americans, it is the fourth leading cause of death in those 45-54 years of age and the sixth leading cause of death in Hispanic Americans.1 In the United States, liver disease mortality has been attributed to individual characteristics such as ethnicity, race, obesity, and alcohol consumption.2, 3, 4, 5 Beyond the impact of individual characteristics on liver disease mortality, assessment of geographic variations may inform health promotion strategies, intervention programs, resource allocation, and health policies. In other disease states, geographic variations have led to impactful preventive measures. For example, description of the “Stroke Belt” in Southern states led to better understanding of demographic and health care system determinants of health with the establishment of research and clinical collaboratives aimed at reducing health disparities.6, 7 Similarly, in an analysis of geographic variations, heart-healthy policies and built environment characteristics significantly impacted cardiovascular mortality.8 Currently, there are no prior studies describing the geographic variation in liver disease across the United States. Therefore, the aim of this study was to examine interstate geographic variability in liver disease mortality in relation to important comorbid conditions.
Methods
Data Sources
This is a cross-sectional analysis of state-specific liver disease mortality rates and factors predicted to be associated with liver disease mortality at a population level. This study was considered exempt from oversight by the University of Arizona Institutional Review Board because it did not meet the definition of research or human subject research. Age-adjusted liver disease mortality rate was derived from the National Vital Statistics in 2010.1
Death rates due to viral hepatitis were derived from the Centers for Disease Control and Prevention reporting of cause of death for 2010.9 Alcohol consumption is defined as an adult reporting having at least one alcoholic drink in the last 30 days in the 2010 Behavioral Risk Factor Surveillance Survey. Obesity is defined as having a body mass index >30.0. Body mass index is calculated by dividing an adult’s self-reported weight in kilograms by the square of their height in meters obtained from the 2010 Behavioral Risk Factor Surveillance System.10
Race and ethnicity were obtained from 2010 Census data. Data reported are weighted averages based on each state’s total population. Ethnicity was broken into 2 large categories—Hispanic or non-Hispanic. Race categories include “White,” “Black or African American,” “American Indian or Alaska Native,” “Asian,” “Native Hawaiian or Other Pacific Islander,” or “Some Other Race.”11 Median household income is derived from the 2010 US Census. It is the median household income for all households in the state over the past 12 months at 2010 inflation-adjusted dollars.12
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-Archita P. Desai, MD, Prashanthinie Mohan, MBA, Anne M. Roubal, PhD, Ricki Bettencourt, MS, Rohit Loomba, MD, MHSc
This article originally appeared in the July issue of The American Journal of Medicine.
