Disparities between research attention and burden in liver diseases: implications on uneven advances in pharmacological therapies in Europe and the USA

Objectives: Effective oral therapies for hepatitis B and C have recently been developed, while there are no approved pharmacological therapies for alcoholic and non-alcoholic fatty liver diseases (ALD and NAFLD). We hypothesise that fewer advances in fatty liver diseases could be related to disparities in research attention. Methods: We developed the Attention- to- Burden Index (ABI) that compares the research activities during 2010- 2014, and an estimate of disease burden of these 4 major liver diseases. The resulting ratio reflects either overattention ( positive value) or inadequate attention (negative value) compared with disease burden. The mean research attention and disease burden were calculated from 5 and 6 different parameters, respectively. The efficacy rate of current pharmacological therapies was assessed from published clinical trials. Findings: The mean research attention for hepatitis B and C was 31% and 47%, respectively, while NAFLD and ALD received 17% and 5%. The overall burden was 5% and 28% for hepatitis B and C, and 17% and 50% for NAFLD and ALD. The calculated ABI for hepatitis B and C revealed a + 6.7- fold and + 1.7- fold overattention, respectively. NAFLD received an appropriate attention compared with its burden, while ALD received marked inadequate attention of - 9.7fold. The efficacy rate of current pharmacological agents was 72% for hepatitis B, 89% for hepatitis C, 25% for non- alcoholic steatohepatitis and 13% for alcoholic hepatitis. Importantly, we found a positive correlation between the mean attention and the efficacy rate of current therapies in these 4 major liver diseases. Interpretation: There are important disparities between research attention and disease burden among the major liver diseases. While viral hepatitis has received considerable attention, there is a marked inadequate attention to ALD. There is a critical need to increase awareness of ALD in the liver research community.