This blog post uses autism as the example but provides a good explanation of the difference between incidence and prevalence: To understand autism you need to understand incidence and prevalence | The Poxes Blog (27 May 2012)
The word prevalence generally means 'how many people have this' and is often expressed as a percentage, or just actual numbers. Incidence means the number of new cases.
The QOF (see also QOF overview) provides a register of people with diabetes in the UK over the age of 17 - there are QOF equivalents in all four nations. Combining these gives the following figures.
2011 - 2.9 million people, 4.45 per cent
2010 - 2.8 million people, 4.26 per cent
2009 - 2.6 million people, 4 per cent
2008 - 2.5 million people, 3.86 per cent
2007 - 2.3 million people, 3.66 per cent
2006 - 2.2 million people, 3.54 per cent
Before 2006 there was no diabetes register and so estimates of numbers of people with diabetes relied on extrapolation from surveys and other small studies.
In 2004 it was estimated to be around 1.8 million
1996 it was just under 1.4 million
1988 the estimate was 750,000.
(See attached files)
1955
"There are about 200,000 diabetics in the United Kingdom today, fo whom about two-thirds take insulin. There are about 1,200 diabetic school children in the country. There are said to be over a million known diabetics in the United States and recent "drives" reveal that the known number might well be very greatly increased if latent, mild and unsuspected diabetics were included.
The malady is believed to be less common in Scandinavian and Latin countries than among English-speaking peoples. There are no data of any value as to the prevalence of the disease in Africa and Asia but some interesting, albeit gloomy, speculations are possible on a world shortage of insulin, which depends on cattle and chemistry, when the peoples of these continents have the same diagnostic facilities as we in western Europe enjoy.
As regards mortality from diabetes the Registrar-General has kindly furnished me with the following report: deaths in England and Wales in 1953 which were assigned to diabetes mellitus as the underlying cause numbered 3,194 (1,066 males, 2,128 females)."
Source: Walker GF (1955) Diabetes Duckworth's Modern Health Series, 3 Henrietta Street, London. Price: 8s.6d net
1952
"nearly a quarter of a million diabetics"
Source: The Diabetic Association - letter to members - this figure conflicts with the 1955 one but I am unable to resolve the difference.