Sirs, The recent paper by AlJuburi et al.1 draws attention to the issue of hospital admissions for sickle cell disease. We would like to raise several points in response. AlJuburi et al. suggest that the increased prevalence of sickle cell disease (SCD) in England through domestic growth of the current at-risk population' is the most important factor contributing to the increase in SCD admissions. Data collected by the NHS Sickle Cell and Thalassaemia Screening Programme show that in England the birth prevalence of screen-positive babies for SCD (comprising FS, FSC, FS-other and FE screening positive results) has been stable between 2005 and 2011 (0.52–0.56/1000 babies screened), with about 360 screen-positive babies per year.2 This demonstrates that there has not been a dramatic increase in the prevalence of (SCD) in England through domestic growth of the current at-risk population, although migration in older children has been reported by some clinics. The authors' analysis gives an indication of the burden of hospital utilization from SCD in England. However, evidence on readmissions and multiple admissions in the same patient are better measures of quality of clinical and community care and are required to gain better understanding of the quality and efficiency of the SCD service rather than simply burden of disease. The NHS Atlas of Variation in Healthcare for Children and Young People reported (a nearly 2-fold) variation in emergency hospital admissions for SCD per individual patient aged 0–17 years by PCT in the 3 year period from 2007 to 2010.3 Highest readmission rates are seen in areas with less expertise in managing SCD, and in areas which have newly arrived populations, many areas in London with high rates of admission do not have high repeat admission rates. Data collected by the NHS Sickle Cell and Thalassaemia Programme shows that the highest birth prevalence is in London South East.2 However, analysis in AlJuburi's study show that five PCTs with highest admission rates are not in South East London. This could be explained with quality of care in above PCTs. We also think that it would be useful to compare the rise of SCD admissions to the overall rise of all hospital admissions. The National Haemoglobinopathy Project has reported a 70% increase in D57 code admissions in the period 1997–2007, while total admissions for all diagnoses rose by only 28% over a similar period.4 Finally, the authors might have considered a cohort effect in the high-risk population (Black African and Black Caribbean)5 and the impact of the changing age structure of those populations on the increase in SCD admissions in older age groups, with patient survival also increasing and thus larger cohorts moving up through the age groupings.