Abstract
There is uncertainty over the population prevalence of people with Down's syndrome in England and Wales. This study aimed to estimate the population prevalence of Down's syndrome in England and Wales in 2011. A meta-analysis of published survival rates of people with Down's syndrome from 1938 to 2010 was conducted and the results were applied to the estimated numbers of babies born with Down's syndrome since 1938 in England and Wales. An estimated 37 090 people had Down's syndrome in England and Wales in 2011, a population prevalence of 0.66 per 1000 people; 650 under 1, 2673 aged 1-5, 7115 aged 5-18, 12819 aged 19-40, 10 626 aged 41-55 and 3207 aged 56 and older. The average life expectancy for babies with Down's syndrome born in 2011 was 51 years and the median life expectancy was 58 years. This study provides clarity on the number of people with Down's syndrome in England and Wales. Owing to sudden increases in the survival of babies with Down's syndrome in the 1950s there are a large proportion of people with Down's syndrome who are in their 40s. These people have an increased risk of developing dementia in the future and services should be aware of their potential needs.