Mapping the prevalence of sickle cell and beta thalassaemia in England: estimating and validating ethnic‐specific rates

Abstract

Summary.A range of estimates for sickle cell and b thalassaemia have been derived for the different ethnic groups living in the U.K., reflecting uncertainty over the true population value in certain countries and the heterogeneity within and between countries of origin comprising the same ethnic group. These were validated against six community screening programmes, with the estimated range correctly predicting the number of affected births observed by the programmes.In England approximately 3000 affected babies (0·47%) carry sickle cell trait and 2800 (0·44%) carry b thalassaemia trait annually; with approximately 178 (0·28 per 1000 conceptions) affected by sickle cell disease (SCD) and 43 (0·07 per 1000) by b thalassaemia major/intermedia. Allowing for termination, about 140-175 (0·22-0·28 per 1000) affected infants are born annually with SCD and from 10 to 25 (0·02-0·04 per 1000) with b thalassaemia major/ intermedia.These are the first evidence-based rates for sickle cell and b thalassaemia for use in the U.K., and should underpin the future planning of services. The long-term solution to monitoring changes in the rates of trait and disease in the population is to introduce a standardized instrument for collecting ethnicity for all community screening programmes.

Sickle cell disease as a paradigm of immigration hematology: new challenges for hematologists in Europe

“…There have been many national and local initiatives in non-endemic countries to obtain accurate, up-todate measures of the changing prevalence of sickle cell disease, 5,7,12,13,15,[17][18][19][20] although attempts to establish comprehensive national registries have so far largely failed, despite individual efforts, because of insufficient funding. 19,21 An alternative approach, which provides an essential starting point for planning purposes, is to estimate the carrier frequency using national population data including information about country of origin.…”

“…Regional variation in the frequency of hemoglobin S (HbS) within the endemic countries of origin leads in turn, through the settling of immigrant populations in localized groups, to foci of high prevalence in their adopted countries (eg London, Birmingham, Paris, Brussels, Madrid and Copenhagen, [12][13][14][15][16] with consequent implications for screening and service provision.…”

Clinical outcomes in children with sickle cell disease living in England: a neonatal cohort in East London

“…22, 23 A joint hospital and community approach to SCD management has evolved over 23 years of continued screening. We wished to analyze outcomes of affected births to provide figures for SCD morbidity and mortality in a UK setting, and to determine whether there are significant differences in outcomes of these patients compared to those in the USA and Jamaica.…”

Ethnicity of children with homozygous c.985A>G medium-chain acyl-CoA dehydrogenase deficiency: findings from screening approximately 1.1 million newborn infants

“…Population denominators were obtained using 2001 UK Census estimates of total births in the UK from routine vital statistics and ethnic group and birth data of children under one year, a method originally described by Hickman et al 15 and subsequently used by Hardelid et al 16 to report ethnic variation in the prevalence of sickle cell disorders and phenylketonuria, respectively. In the UK Census, parents are required to assign an ethnic group for their children using a choice of categories.…”