Effect of immigration on mortality trends in sickle cell patients

Sickle cell patient population in the U.S. continues to increase due a combination of birth of sickle cell disease infants, extension of lifespan of existing patients and also possibly, a contributing immigration component. These factors and most importantly the latter, might be altering national estimates by both underestimating the number of affected individuals as well as underestimating the impact of public health strategies given the estimates for which there were conceived.

National sickle cell disease estimates as per Centers for Disease Control (CDC) and immigrant population trends obtained from the U.S. Census Bureau from years 2010-2017 were examined. Immigrant groups from geographical regions highly prevalent for sickle cell disease were evaluated throughout this period of time.

From years 2010 to 2017 Western Africa (Nigeria, Ghana, Cape Verde, Liberia, Sierra Leona), showed a population increase of 45.2%, 44.15%, 24%, 19.0% and 16.3% respectively. Eastern Africa (Ethiopia, Kenya and Eritrea) had a population increase of 55.7%, 46.8% and 65% respectively. Caribbean island (Dominican Republic, Haiti and Jamaica) showed an increase of 31.8%, 18.6% and 46.8% respectively. Extrapolation of the prevalence in these populations shows that the sickle cell disease prevalence is likely higher than what is reported in US.

The complexities of reaching an estimated number may be more challenging in an ever-changing and growing population. More so considering the different situations behind the immigration of each group and the migratory status which might be inducing an underestimation of the sickle cell population in the U.S. This study attempts to shed light on factors that may be skewing previous statistical estimates. Examining the migratory aspects inducing possible statistical bias may contribute to further address this disease encompassing this population's growth rate into prospective public health strategies to a more comprehensive approach to the disease.