brynpoeth wrote:Average: mean, median mode or..?
It's not going to be modal as this would result in the average life expectancy in some populations to be zero years.
brynpoeth wrote:Average: mean, median mode or..?
But the people who are living longer today are by definition in their eighties - at least that is what I presume is meant by longevity, not that more people for example are surviving to adulthood.
rfryer wrote: ... I think that most people's view of longevity of a population (ie "people born in 1920") is the (mean) average lifetime they achieve. If you want to use a different measure, which somehow excludes deaths at a young age, then it might be helpful if you could be explicit about what that measure is.
horizon wrote:My point is that this increase in longevity has largely been claimed as a result of developments in modern medicine. I would say (and have done so in the past, though not on this forum) that while this is an attractive idea it is less likely than ten years of enforced dieting during and after the war and that when this generation dies out, the next will revert to a shorter life span.
in Kensington and Chelsea, a ward in the wealthiest part of London, a man can expect to live to 88 years, while a few kilometres away in Tottenham Green, one of the capital’s poorer wards, male life expectancy is 71 years.
Secondly, there are huge discrepancies in life expectancy in the UK by post code. A number of studies have correlated these discrepancies with variations in income deprivation. For examplein Kensington and Chelsea, a ward in the wealthiest part of London, a man can expect to live to 88 years, while a few kilometres away in Tottenham Green, one of the capital’s poorer wards, male life expectancy is 71 years.
horizon wrote: ... I'm struggling a bit here with both definitions and statistics (I'm no expert on this), but AIUI this isn't to do with life expectancy but with how long people are actually living. ....
horizon wrote: ... The fact that life expectancy/longevity are no longer increasing ....
... you are dismissing - or at least minimising - the effects of improving knowledge about health as shown in public health programmes and medical interventions and then emphasising the benefits of enforced dieting through war-time and post-war food rationing and the health benefits of a lack of private motor transport.
In the 20 years between 1991 and 2011, life expectancy at birth for females in England and Wales grew by almost four years and for males by more than five years (see National life tables, UK: 2014 to 2016).
However, since 2011 there has been a reduction in the rate of improvement. Between 2011 to 2013 and 2014 to 2016, only 26 local authorities showed any statistically significant increase in life expectancy for men, and only 17 showed any improvement for women. This compares to 203 and 128 local authorities respectively showing a significant increase in the equivalent period 10 years earlier (see Health state life expectancies, UK: 2014 to 2016). There is debate about the reasons for the recent findings and whether they represent only a “blip” in the long-term pattern of improvement or a real change of direction (see the Why have improvements in mortality slowed down? blog by The King’s Fund, which summarises the debate).
Two factors are uncontested. The first is the slowing of mortality improvements is principally the result of changes in mortality among older people. Put simply, more older people – particularly older women – than expected given historical trends are dying. The second is that flu contributed to excess deaths in some years, notably 2015 and also in 20171, although the scale of its impact is disputed. Beyond this, views about the underlying factors are hotly contested.
Several researchers cite the impact of austerity, which some claim has resulted in tens of thousands of ‘extra’ deaths.2345 Their conclusions are based on statistical analyses examining associations between mortality trends on the one hand, and external factors such as the slowing of NHS spending, cuts in social care budgets, increases in delayed discharges and reductions in benefits on the other.
However, this interpretation has been challenged, mainly on the grounds that association doesn't prove causality,678 with some arguing that because pensioners have, in fact, been better protected from spending cuts than other groups, austerity cannot be the reason for the change in the long-term trend. Alternative explanations suggested include: a ‘cohort effect’ with gains from, eg reducing smoking, largely already realised; or that older people may be succumbing to more complex and multiple long-term conditions.
Then, there is the influence of statistical artefacts – for example, trends can look different depending on the period over which they are measured9 – and, more fundamentally, the calculation of mortality rates10 is affected by changes in population size and structure and whether these have been suitably adjusted for.
With such a long list of possible explanations, what are we to believe? Understanding the reasons for recent trends in mortality among older people is largely – but not solely – the key to understanding what's happening. But disentangling the effects of the many different factors affecting older people's mortality is immensely challenging.
Vorpal wrote:For what it's worth, I think it is unreasonable on any scientific basis to dismiss the affects of immunisation against polio, rubella, mumps, measles, etc. which ensured that many thousands more children survived their childhoods compared to earlier decades.