Assessing the Relationship between Chronic Lymphoid Leukemia Mortality Rates and Human Development Index: A 26-Year Trend Analysis Using Location-Scale Mixed Effects Model

Background Chronic lymphoid leukemia (CLL) is one of the most prevalent types of leukemia, which is responsible for a remarkable mortality rate in the world. This study aimed to investigate the global trend of this cancer from 1990 to 2015 and to determine the relationship between trend of CLL mortality rate and Human Development Index (HDI) throughout the world. Methods The age-standardized mortality rate data of all countries of the world (per 100,000) were extracted from the GBD database. In addition, the HDI values for the studied countries in different years were obtained from the UNDP database. The statistical analysis was performed using the mixed-effects location-scale model in the SAS software, version 9.4. Results The findings of the statistical modeling showed a downward slope for CLL Age Standardized Mortality Rate (ASMR) for total world countries (β = -0.002). We also find a significant association between CLL ASMR and HDI. Countries with higher HDI had higher level of CLL ASMR in years 1990 to 2015 with a negative slope. Furthermore, countries with lower HDI had Lower level of CLL ASMR with rather fixed rates in this period. Conclusion These findings showed a decreasing trend of global CLL ASMR in the previous decades, although, the fixed trend of CLL ASMR in countries with low HDI is worrisome. The health policymakers should make more efforts to decrease the mortality due to this cancer in these countries.