People regularly refer to the life expectancy that may or may not change. I don't see much in the "life expectancy" unit because he says far too little to me. Dutch life expectancy a month longer or shorter, how bad is that? Then I first have to consider what a year, month or a week of life expectancy means, for example in QALY terms, before I can think in terms of 'life expectancy'. That's why I did some math.
Life expectancy is generally spoken of every 0.1 years, i.e. accurate to one decimal place. In Statline tables (CBS), up to two decimal places are calculated per age group. That is therefore 1/100 years or about 3.65 days accurate, but usually, especially when it comes to averages, it is calculated in tenths, so for example 83.1 years. See https://www.volksgezondheidenzorg.info/onderwerp/levensverwachting. That's the most common so I'll continue with that.
What is QALY
1 QALY is a "Quality Adjusted Life Year" or a full year in good health. If the health or well-being is not good, then a year of life does not stand for 1 QALY. This can be, for example, 0.6 QALY or lower, for people who lead an unhappy, painful or inhumane life for a full year.
The formula is: Life years x Utility value = #QALY
This means:
If a person lives in perfect health for a year, that person has realized 1 QALY.
(1 year of life × 1 utility value = 1 QALY)
If a person lives in perfect health, but only for half a year, that person has 0.5 QALY.
(0.5 years of life x 1 utility value = 0.5 QALYs)
Conversely, if a person lives in a situation with 0.5 utility (half of perfect health) for 1 year, that person will also have 0.5 QALYs.
(1 year of life x 0.5 utility value = 0.5 QALYs)
More examples can be found at https://www.celforpharma.com/insight/do-you-know-what-qaly-and-how-calculate-it
1 year life expectancy = approx. 16,000,000 QALY
You can see life expectancy as a qaly calculation or vice versa. The relationship is obvious: for each additional year of life, an average of 1 year of life becomes older. It's just about the big picture: 17 million QALY is 1 year for the Netherlands with 1 QALY per inhabitant.
But: there are sick people, elderly people who actually no longer want to, about 210,000 people who will not make it to the turn of the year anyway (that is already more than 105,000 QALY), people who give their quality of life a failing grade for mental or physical health reasons, etc. Also about 210,000 are born during that year, another 105,000 QALY. All in all reason because number of 17 million to reduce: we make 16 million of it.
[This is an example number. If you don't agree: take another number in the QALY/Life expectancy calculator below. For the order of magnitude of the numbers, it doesn't matter much.]
Conversions
16 million QALY per year, that is 4 million QALY per quarter, 1,333,333 QALY per month life expectancy, 307,692 QALY per week life expectancy.
You can say the other way around: every 0.1 year of life expectancy corresponds to 1,600,000 QALY (one-tenth of 16 million). An extension or shortening of less than 800,000 QALY is therefore no longer reflected in the average life expectancy, while a shortening of 0.05 years (5% of a year) will still involve the early death of (tens of) thousands of people. Suppose that the calamity of 0.05 years shortened life expectancy mainly affects 1 age group.
People over forty: if they have an average of 40 years to live, it is about 20,000 deaths.
People over sixty: if they have an average of 20 years to live, this concerns 40,000 people. So 40,000 elderly people can die prematurely without this having a noticeable effect on life expectancy, if there is one decimal place.
Seventy-somethings: If it is mainly about 70-somethings with about 10 years ahead of them, then it is even about 80,000 people. (You notice, I'll finish easily).
Young people
If it concerns people in their twenties, who still have 60 years ahead of them, then it ticks harder. Then shortening 0.1 years involves "only" 13,333 people in their twenties. Terrible numbers; a horror– and they are barely reflected in the rough-grained estimate of average life expectancy that is sometimes considered a gauge.
The above is quickly calculated, only intended to get a feel for the ratio between those two units. For me a reason not to be so busy with life expectancy. If it only drops 0.1 at all, the smallest unit, then that is already a disaster. Especially if the trend was actually upwards. From 83.2 to 83.1 years does not look dramatic. It sounds like people who used to be 83.2 have now turned 83.1. In any case, that makes me tend to put things into perspective: "Can happen, it is also quite a respectable age that you have reached, a minimal difference actually ..."
If you think of the suffering that can be behind it, then I prefer a more accurate scale: QALY.
Future
Life expectancy is a concept with which well-being between countries can be compared, but otherwise... As if life expectancy is going down because of a temporary epidemic?! I just don't follow that train of thought. If Covid is gone, will we be left with a structurally lower life expectancy? Isn't that big nonsense?
In retrospect, after an epidemic disaster, for example, you can say that so many younger people have died that the average life expectancy has not been achieved. But that doesn't count towards future life expectancy. Life expectancy does not decrease due to a temporary cause. This is possible if people have been given so much systemic damage during the crisis that they will live shorter lives. That possibility is absolutely there, but we will have to wait and see if any long-term effects in the coming years. Those in the short term have already clearly emerged.
