Religion and Ethics Forum
General Category => General Discussion => Topic started by: wigginhall on April 17, 2019, 03:31:08 PM
-
Not being a statistician, I need help with bacon. Another report today that every slice of bacon or ham increases the risk of bowel cancer by 20% Now this puzzles me, because if about 6% of people will develop bowel cancer, that 20% figure applies to the 6% who will get cancer. This means a 1% rise, doesn't it? Or does it mean that the 94% who won't get cancer, are more likely to?
If I have made a Horlicks of this, please tell me.
-
Wiggs,
Not being a statistician, I need help with bacon. Another report today that every slice of bacon or ham increases the risk of bowel cancer by 20% Now this puzzles me, because if about 6% of people will develop bowel cancer, that 20% figure applies to the 6% who will get cancer. This means a 1% rise, doesn't it? Or does it mean that the 94% who won't get cancer, are more likely to?
If I have made a Horlicks of this, please tell me.
Let me help you. If every slice increases the chance of bowel cancer by 20%, that means that five slices equals 100% so you're guaranteed to get it. That's why I've only ever eaten four slices of bacon. I'm taking no chances me.
Oh hang on though - do smokey bacon crisps count? Bugger....
-
Not being a statistician, I need help with bacon. Another report today that every slice of bacon or ham increases the risk of bowel cancer by 20% Now this puzzles me, because if about 6% of people will develop bowel cancer, that 20% figure applies to the 6% who will get cancer. This means a 1% rise, doesn't it? Or does it mean that the 94% who won't get cancer, are more likely to?
If I have made a Horlicks of this, please tell me.
It would mean 20% greater than the existing risk. So if your existing risk was 5% the 20% increased risk would mean you final risk would be 6%.
These stats are pretty well meaningless unless you know the starting point risk. So if you had a one in ten thousand chance (0.01%) chance of getting a disease and doing something increased that risk by three fold (300% increase) then your final risk would still only be 3 in ten thousand (0.03%) so there isn't much point worrying as the likelihood of not getting the disease is pretty well indistinguishable (99.99% vs 99.97%).
If the starting point risk is 6%, well that's quite a different matter.
-
Well, I think 6% is the incidence often cited for bowel cancer, so the 20% rise figure is misleading.
Blue, damn, forgot about crisps.
-
Well, I think 6% is the incidence often cited for bowel cancer, so the 20% rise figure is misleading.
Blue, damn, forgot about crisps.
I don't think it is misleading - it just means that the final risk is 20% higher than the initial (6%) risk, in other words 7.2%.
-
We never have a cooked breakfast so it is very rare for us to eat bacon.
-
Floo,
We never have a cooked breakfast so it is very rare for us to eat bacon.
Breakfast? You can have it for breakfast as well as for lunch and dinner (plus a late night snack of course)? Oh Lordy...!
-
Prof,
I don't think it is misleading - it just means that the final risk is 20% higher than the initial (6%) risk, in other words 7.2%.
Actually I think it can be presented very misleadingly. The press will often say something like "increases the risk by 20%" which at first pass can be misinterpreted as "increases the risk to 20%". Or worse, you might think that a background rate of, say, 5% would then be 25% for the bacon eaters. That's the trouble with headlines - short (but misleading) summaries fit the page better than longer (but accurate) ones.
-
Floo,
Breakfast? You can have it for breakfast as well as for lunch and dinner (plus a late night snack of course)? Oh Lordy...!
We have had it occasionally if I have done a fry up for lunch, but I can't remember when we last had it. We never have snacks, and don't eat anything after 6pm.
-
And while we're on the subject of background risk, "Knife murders increases by 100%" is terrifying right, unless that is the rate has gone from 1:1,000,000 to 2:1,000,000 (ie, a 100% increase) in which case you're probably not going to change your behaviour much in response, albeit that it's still a tragedy for the two victims.
-
I don't think it is misleading - it just means that the final risk is 20% higher than the initial (6%) risk, in other words 7.2%.
is it? Or is it an increase of .2% v the 94%? Stats need context. Assuming the context is not a good position
-
Prof,
Actually I think it can be presented very misleadingly. The press will often say something like "increases the risk by 20%" which at first pass can be misinterpreted as "increases the risk to 20%". Or worse, you might think that a background rate of, say, 5% would then be 25% for the bacon eaters. That's the trouble with headlines - short (but misleading) summaries fit the page better than longer (but accurate) ones.
But that is about the presentation of the stats to sell papers rather than the stats themselves.
-
is it? Or is it an increase of .2% v the 94%? Stats need context. Assuming the context is not a good position
Eh - don't understand your maths.
Clearly if the risk is increased it relates to the original risk of something happening, not the non-risk of something not happening.
-
Prof,
But that is about the presentation of the stats to sell papers rather than the stats themselves.
I agree, but the point I think was that the presentation can be misleading even when the research paper being cited isn't.
-
Prof,
I agree, but the point I think was that the presentation can be misleading even when the research paper being cited isn't.
Which requires the media to be more responsible in their presentation - plus also a better informed, more numerate, reader/viewership to be able to see the wood for the trees.
-
Eh - don't understand your maths.
Clearly if the risk is increased it relates to the original risk of something happening, not the non-risk of something not happening.
is it clear? Because that's just your assumption.
-
is it clear? Because that's just your assumption.
Yes it is clear - if it describes an 'increased risk' the baseline is clearly the initial risk.
Still don't understand your maths though
-
Prof,
Which requires the media to be more responsible in their presentation - plus also a better informed, more numerate, reader/viewership to be able to see the wood for the trees.
Yes indeed. How do we achieve all that though, especially in this age of citizen journalism where anything pretty much goes?
Just to develop the nonsense by the way, if the background risk of getting the cancer is 5%, that means the chances of not getting it must be 95%. So if the chances of getting it post full English breakfast go up by 20%, that must mean that the chances of not getting it also decrease by the same 20%, so instead of 95% it’s now 76%!
Yikes!
-
Yes it is clear - if it describes an 'increased risk' the baseline is clearly the initial risk.
Still don't understand your maths though
you just worship at the goddess of assumption.
-
There is a further complexity here, which is the proportion of people who do, and do not eat bacon (in this case).
Wiggs assumes the increase is over the starting point 6%, but this is the risk for the whole population - in other words those that do and those that do not eat bacon. The actual 20% increased risk is comparing those that do eat bacon with those that don't. In a world where most people do eat bacon then the risk of eating bacon is only a touch higher than the 6% of the whole population. The big difference would be a decreased risk (down to about 5% for those that don't eat bacon.
-
you just worship at the goddess of assumption.
Sometime you simply have to assume that people are able to understand simple english - in other words that 'every slice of bacon or ham increases the risk of bowel cancer by 20%' means just that, an increased risk.
-
NS,
you just worship at the goddess of assumption.
Well, maybe he’d be in good company if he does:
Catholic Mariology
"The four dogmas of perpetual virginity, Mother of God, Immaculate Conception and Assumption form the basis of Mariology."
https://en.wikipedia.org/wiki/Catholic_Mariology
-
Sometime you simply have to assume that people are able to understand simple english - in other words that 'every slice of bacon or ham increases the risk of bowel cancer by 20%' means just that, an increased risk.
In the case of science reporting, your assumption just makes you assuming, and based on evidence against it.
-
NS,
Well, maybe he’d be in good company if he does:
Catholic Mariology
"The four dogmas of perpetual virginity, Mother of God, Immaculate Conception and Assumption form the basis of Mariology."
https://en.wikipedia.org/wiki/Catholic_Mariology
So they are a perpetual virgin?
-
Prof,
Sometime you simply have to assume that people are able to understand simple english - in other words that 'every slice of bacon or ham increases the risk of bowel cancer by 20%' means just that, an increased risk.
But look at the ambiguities in that "every"! Clearly it can't actually mean "every" or just one slice eaten by an otherwise lifelong vegetarian would have the same effect wouldn't it? So does it mean the 20% increase is for people who eat just one rasher every day? And if it does, does that mean that eating more than one rasher every day increases the risk even more? I think we should be told!
-
NS,
So they are a perpetual virgin?
Given all that bacon they're eating, probably...
-
In the case of science reporting, your assumption just makes you assuming, and based on evidence against it.
You have to set the bar somewhere - you cannot assume that no-one is able to understand basis English and the meaning of words put together into a simple phrase like increases the risk.
And you are correct, you have to make an assumption either way - you either assume that people are able to understand simple English or you assume that people aren't able to understand simple English - I think the former is better as it doesn't stilt discussion and it means you don't constantly patronise people by assuming they can't understand basic English.
How are you getting on with that maths working out?
-
You have to set the bar somewhere - you cannot assume that no-one is able to understand basis English and the meaning of words put together into a simple phrase like increases the risk.
And you are correct, you have to make an assumption either way - you either assume that people are able to understand simple English or you assume that people aren't able to understand simple English - I think the former is better as it doesn't stilt discussion and it means you don't constantly patronise people by assuming they can't understand basic English.
How are you getting on with that maths working out?
You can make that assumption. Reading reporting of science in the media might make you wonder but on you go with you thinking it's all good with your assumption, and licking the boots of science reporting in the media.
-
NS,
Given all that bacon they're eating, probably...
I think that's a bit rasher!
-
Prof,
But look at the ambiguities in that "every"! Clearly it can't actually mean "every" or just one slice eaten by an otherwise lifelong vegetarian would have the same effect wouldn't it? So does it mean the 20% increase is for people who eat just one rasher every day? And if it does, does that mean that eating more than one rasher every day increases the risk even more? I think we should be told!
Yes - that's non-sense reporting. A single slice of bacon doesn't increase the risk of bowel cancer by 20% (or at least there is no evidence in the study to support that notion). What the study found was that people who eat red and processed meat four or more times a week had a 20% greater likelihood of being diagnosed with bowel cancer compared to those who eat read and processed meat less than twice per week.
The Independent reporting (although perhaps not the headline) is fairly clear:
https://www.independent.co.uk/news/health/bowel-cancer-bacon-sausage-red-meat-processed-oxford-health-a8872716.html
-
You can make that assumption. Reading reporting of science in the media might make you wonder but on you go with you thinking it's all good with your assumption, and licking the boots of science reporting in the media.
Not only do you seem unable to understand simple English, you have now ceased to be able to write it either. Have you morphed into Vlad ;)
-
Not only do you seem unable to understand simple English, you have now ceased to be able to write it either. Have you morphed into Vlad ;)
One of your usual tropes when you have lost the argument.
-
One of your usual tropes when you have lost the argument.
What argument?!?
How's that maths coming along? Ready to share?
-
What argument?!?
How's that maths coming along? Ready to share?
The one you lost when you admitted to making assumptions about science reporting.
And btw I think you mean arithmetic.
-
The one you lost when you admitted to making assumptions about science reporting.
I didn't make any assumptions about science reporting, I made an assumption about people's ability to read simple English - in other words to understand what the phrase increases the risk means.
That is perfectly reasonable I'm afraid as to assume that people cannot understand what the phrase increases the risk (or any other simple phrase) means would mean we'd spend our who time constantly explaining simple phrases to each other, which would kill any kind of discussion and would be deeply patronising.
I make no apology for assuming that posters here are able to understand what increases the risk means. Wiggs OP wasn't about that, but about what the stats around it meant.
-
And btw I think you mean arithmetic.
Into pedantry now - sorry I must not assume you know what pedantry means, so here is the dictionary definition:
'excessive concern with minor details and rules'
Oops better explain what 'excessive', 'concern', 'minor details' and 'rules' means now - see where we get when we don't assume people are capable of understanding simple English NS.
-
I didn't make any assumptions about science reporting, I made an assumption about people's ability to read simple English - in other words to understand what the phrase increases the risk means.
That is perfectly reasonable I'm afraid as to assume that people cannot understand what the phrase increases the risk (or any other simple phrase) means would mean we'd spend our who time constantly explaining simple phrases to each other, which would kill any kind of discussion and would be deeply patronising.
I make no apology for assuming that posters here are able to understand what increases the risk means. Wiggs OP wasn't about that, but about what the stats around it meant.
I really hope you never pass a mirror, asumptionist.
-
Into pedantry now - sorry I must not assume you know what pedantry means, so here is the dictionary definition:
'excessive concern with minor details and rules'
Oops better explain what 'excessive', 'concern', 'minor details' and 'rules' means now - see where we get when we don't assume people are capable of understanding simple English NS.
Long winded but a perfect illustration of the word irony from you
-
And btw I think you mean arithmetic.
Would you like to share your arithmetic workings with us please - the one that construed a 20% increased risk on a base risk of 6% as: "an increase of .2% v the 94%"
-
I really hope you never pass a mirror, asumptionist.
Blimey spelling is suddenly the next element after inability to understand or to write simple English.
-
NS,
Well, maybe he’d be in good company if he does:
Catholic Mariology
"The four dogmas of perpetual virginity, Mother of God, Immaculate Conception and Assumption form the basis of Mariology."
https://en.wikipedia.org/wiki/Catholic_Mariology
Not sure I think that's such good company.
-
NS,
I think that's a bit rasher!
Oh rind yer neck in why doncha... ;)
-
Where the thing that is being discussed (e.g. eating red and processed meat every other day) is probably very common and likely the majority situation I think it might be better, and more positive, to turn the reporting on its head. In other words to say that if you reduced consumption you would reduce your risk of cancer.
-
Blimey spelling is suddenly the next element after inability to understand or to write simple English.
woo it's a spelling thing to make an argument. How exciteing!
-
NS,
Oh rind yer neck in why doncha... ;)
We are on a streaky here
-
Where the thing that is being discussed (e.g. eating red and processed meat every other day) is probably very common and likely the majority situation I think it might be better, and more positive, to turn the reporting on its head. In other words to say that if you reduced consumption you would reduce your risk of cancer.
said a sponsor for the eating of pigs industry
-
Prof,
Yes - that's non-sense reporting. A single slice of bacon doesn't increase the risk of bowel cancer by 20% (or at least there is no evidence in the study to support that notion). What the study found was that people who eat red and processed meat four or more times a week had a 20% greater likelihood of being diagnosed with bowel cancer compared to those who eat read and processed meat less than twice per week.
The Independent reporting (although perhaps not the headline) is fairly clear:
https://www.independent.co.uk/news/health/bowel-cancer-bacon-sausage-red-meat-processed-oxford-health-a8872716.html
Yes I get that - drill down a bit and you can get the sense of it. You have to admit though that linking "every slice" with a 20% risk increase is potentially at least very misleading.
Reminds me a bit of the headlines a while back that cats falling from above six-storey heights suffered fewer injuries than those falling from lower heights. Various explanations were offered too - maybe the longer fall gave them more time to reorientate feet down, maybe they reached a velocity at which their fur would have a parachute effect etc. Turned out they were more likely to die than to be injured, and dead cats don't get taken the vet so there were fewer reports of injures. Funny things sometimes, statistics.
-
said a sponsor for the eating of pigs industry
Last time I looked not all red and processed meat was produced from pigs.
-
Prof,
Yes I get that - drill down a bit and you can get the sense of it. You have to admit though that linking "every slice" with a 20% risk increase is potentially at least very misleading.
Yup completely misleading, particularly as the comparison was between people who eat on average 76g of red and processed meat a day compared to people eating 21g a day.
You also have to be careful that the study fully factors out other linked effects - e.g. obesity. It could be that being overweight is the driving factor rather than red and processed meat eating per se, and that people who tend to eat the most red and processed meat tend also to be the more overweight.
You need to be very careful that association and causation aren't confused.
-
Last time I looked not all red and processed meat was produced from pigs.
Feck me, a humour bypass has been successful
-
Prof,
Yup completely misleading, particularly as the comparison was between people who eat on average 76g of red and processed meat a day compared to people eating 21g a day.
You also have to be careful that the study fully factors out other linked effects - e.g. obesity. It could be that being overweight is the driving factor rather than red and processed meat eating per se, and that people who tend to eat the most red and processed meat tend also to be the more overweight.
You need to be very careful that association and causation aren't confused.
Yep - and you have to be careful too about unintended consequences. I have no idea whether bacon contains anything that's good for us but if, say, it's a main source of iron (as I believe red meat is) and people stopped eating it the consequence could be that different illnesses would increase. It's a bit like the cycling stats - one-in-X rides will result in a fatality, but if the Y million cyclists there are sat on the sofa instead the death toll from heart disease etc would be much higher. Of course the answer is to make the options non-binary - go to the gym instead, but then perhaps there'd be more road accidents, more exhaust pollution as a result of people driving there. Risk and perception of risk are in other words not the same thing.
-
Prof,
Yep - and you have to be careful too about unintended consequences. I have no idea whether bacon contains anything that's good for us but if, say, it's a main source of iron (as I believe red meat is) and people stopped eating it the consequence could be that different illnesses would increase. It's a bit like the cycling stats - one-in-X rides will result in a fatality, but if the Y million cyclists there are sat on the sofa instead the death toll from heart disease etc would be much higher. Of course the answer is to make the options non-binary - go to the gym instead, but then perhaps there'd be more road accidents, more exhaust pollution as a result of people driving there. Risk and perception of risk are in other words not the same thing.
True - we need to look at the range of factors that affect health and how they inter-relate.
And perhaps the elephant in the room is poverty - I wouldn't be surprised if there is a relationship between deprivation and eating large amounts of processed meat, which tends to be both cheap and lasts a long time compared to fresh ingredients. The link between deprivation and poor health is scary. Where I work in East London, one of the most deprived areas in the UK, the life expectancy is five years less than in Kensington & Chelsea, which is less than 6 miles away.
-
when you say 'deprived areas' are you referring to levels of intelligence ?
-
True - we need to look at the range of factors that affect health and how they inter-relate.
And perhaps the elephant in the room is poverty - I wouldn't be surprised if there is a relationship between deprivation and eating large amounts of processed meat, which tends to be both cheap and lasts a long time compared to fresh ingredients. The link between deprivation and poor health is scary. Where I work in East London, one of the most deprived areas in the UK, the life expectancy is five years less than in Kensington & Chelsea, which is less than 6 miles away.
They seem to have adjusted for deprivation and other health factors in their analysis:
Diet and colorectal cancer in UK Biobank: a prospective study (https://academic.oup.com/ije/advance-article/doi/10.1093/ije/dyz064/5470096?searchresult=1#133824902)
-
when you say 'deprived areas' are you referring to levels of intelligence ?
No - levels of deprivation, broadly speaking poverty.
-
I don't think it is misleading - it just means that the final risk is 20% higher than the initial (6%) risk, in other words 7.2%.
Where are we getting 6% is the initial risk from? If 6% is the overall rate of bowel cancer in the UK, then it already has the people who eat too much red meat baked in. So, if you eat more than the four portions a week, your risk is probably higher than 6% but not as by anything like as much as 20% higher and reducing your intake to less than two portions a week may reduce your risk to lower than 6% but not necessarily to 5%.
-
I've just listened to this report on ITV NEWS and although very slickly presented the science content was sadly lacking to the extent it was meaningless .
typical!
-
Where are we getting 6% is the initial risk from? If 6% is the overall rate of bowel cancer in the UK, then it already has the people who eat too much red meat baked in. So, if you eat more than the four portions a week, your risk is probably higher than 6% but not as by anything like as much as 20% higher and reducing your intake to less than two portions a week may reduce your risk to lower than 6% but not necessarily to 5%.
It's from the same databank used for the study, which contains health and diet data for about half a million people over 6 years. The 20% is the difference between those consuming around 29g processed meat vs 5g average per day.
-
I've just listened to this report on ITV NEWS and although very slickly presented the science content was sadly lacking to the extent it was meaningless .
typical!
The Independent link provide by ProfD seems to have a reasonable level of detail (apart from the general rubbish all over the website). The BBC page (https://www.bbc.co.uk/news/health-47947965) is also OK.
On broadcast media they assume that no-one has the attention span for anything mathsy (even the maths programmes occasionally hidden away on BBC4). "More or Less" on R4 is probably the best available.
-
Where are we getting 6% is the initial risk from? If 6% is the overall rate of bowel cancer in the UK, then it already has the people who eat too much red meat baked in. So, if you eat more than the four portions a week, your risk is probably higher than 6% but not as by anything like as much as 20% higher and reducing your intake to less than two portions a week may reduce your risk to lower than 6% but not necessarily to 5%.
Yup - that was my point in a later post I made - the 20% is the increase from eating low levels of red and processed meat to high levels, not the increase from bowel cancer levels in the general population.