Small Data: Are Rwandans healthier than the English?
Are people living in Rwanda really likely to live more years in good health than people in the most deprived 10% of England, asks Anthony Reuben.
You would certainly think that if you read some news articles on the subject at the end of last week.
It was based on a publication on Thursday from the Office for National Statistics, which showed the inequality in healthy life expectancy across England.
At birth, the top 10% of people could expect to live for 71 years in good health. The bottom 10% had a healthy life expectancy of 52 years.
That 18-year gap between the highest and lowest healthy life expectancy is quite startling, but does it mean the bottom 10% are in a worse situation than people living in Rwanda?
The figures for Rwanda come from the World Health Organization. It tells us that in 2012, people born in Rwanda had a healthy life expectancy at birth of 55 years.
Incidentally, that is an extraordinary improvement for Rwanda, which only 12 years earlier had a healthy life expectancy of 40.
And it makes it look as if Rwandans have a higher healthy life expectancy than the most deprived 10% of people in England. But if you scroll down to the WHO figures on the UK, they give a healthy life expectancy of 71 years, which is about the same as the ONS figures gave for the healthiest 10% in England.
That suggests that the ONS and the WHO are using different methods of calculating healthy life expectancy, which is indeed the case.
What accounts for the difference is that the WHO's survey asks detailed questions about people's health and uses the answers to subtract years of ill-health from life expectancy figures, weighted according to the severity of the ill health. The ONS's Annual Population Survey just asks people if their health is very good, good, fair, bad or very bad.
The WHO's methodology tends to lead to fewer people being classified as being in ill health.
The organisation also warns about the challenges of collecting such data in lower income countries, which makes international comparisons difficult.
We do not know how people in the most deprived 10% of areas in England would come out under the WHO's methodology, but they are likely to get a higher healthy life expectancy than they do under the ONS system.
So we do not know whether those 10% have a lower healthy life expectancy than the people of Rwanda - sorry.
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