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Blindness/Amputation risk prediction equations from BMJ
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Dark Horse
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Interesting, thanks. The calculator it links to is here:-
http://qdiabetes.org/amputation-blindness/index.php
http://qdiabetes.org/amputation-blindness/index.php
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The calculator can't take an HbA1c under 40, so I put 40 in. My chances of amputation or blindness is allegedly 0.6% and 1.2% respectively.
It's somewhat unfortunate the calc doesn't allow calculation based on no diabetes diagnosis. His stroke calc does the comparison.
It's somewhat unfortunate the calc doesn't allow calculation based on no diabetes diagnosis. His stroke calc does the comparison.
Bluetit1802
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phoenix
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The post code is to do with relative deprivation; sadly people in areas of higher deprivation are at far higher risk of complications.
When they devised the calculator they defined T2 as a person who developed diabetes before the age of 35 and went straight onto insulin.
So theoretically I should put in T2 which lowers my risk of blindness but doesn't change the amputation figure. Time with diabetes, also and not surprisingly increases the risk over the next ten years .
When they devised the calculator they defined T2 as a person who developed diabetes before the age of 35 and went straight onto insulin.
So theoretically I should put in T2 which lowers my risk of blindness but doesn't change the amputation figure. Time with diabetes, also and not surprisingly increases the risk over the next ten years .
is it possible the postcodes also include how good diabetes services are? my midlands postcode gives me an extra 0.9% increased risk of blindness, (no current eye problem), and an extra 0.2% increased risk of amputation at both 50 and 54 HbA1c, compared with my old london postcode.
phoenix
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They actually say in the paper that the model uses the Townsend deprivation index, linked to postcodes (they refer back to the paper describing the methods behind the cardiovascular risk index (QRISK2) where they say "This score has already been integrated into the EMIS clinical system and linked to the records of over 32 million patients."
It does make a difference which is magnified as other risk factors increase. Some of those factors have a much bigger influence.
If it's an accurate risk calculator then it does show is that the risks are for many people, much lower than is sometimes suggested.
To try to get someone with a high risk I put in a 65 year old woman, with T1 (unfortunately always seems higher risk) for over 10 years, she smoked heavily, she had a systolic blood pressure of 190 and a cholesterol/HDL ratio of 4 and an HbA1c of 100.
With no existing complications she had a risk of 11.9% for amputation and 13.1% for blindness in the next 10 years; so still a much higher likelihood of them not happening.
Perhaps though this would be a bit of an exception, maybe the woman would already have some complications . This is indeed where the risk increases.
If she had peripheral vascular disease already then the risk went up to 41.6% for amputation; very much worse odds.
If she already had retinopathy, the risk for blindness increased to 31.2% ( Unfortunately, you don't know if you are going to be the 1/3 such people who go blind or the 2/3 that don't; )
Move that lady up the road to an area with a lower deprivation score; the same lady with existing peripheral vascular disease has a risk of amputation at 37.4%.( so slightly reduced )
With existing retinopathy that lady now has a risk for blindness of 24.5% (reduced by a bit more)
(I used this site plus a postcode side to choose my places; I won't say where they were but they were near to each other, one with a very high deprivation ranking and one in the bottom ie least deprived 10%.
http://apps.opendatacommunities.org/showcase/deprivation )
It does make a difference which is magnified as other risk factors increase. Some of those factors have a much bigger influence.
If it's an accurate risk calculator then it does show is that the risks are for many people, much lower than is sometimes suggested.
To try to get someone with a high risk I put in a 65 year old woman, with T1 (unfortunately always seems higher risk) for over 10 years, she smoked heavily, she had a systolic blood pressure of 190 and a cholesterol/HDL ratio of 4 and an HbA1c of 100.
With no existing complications she had a risk of 11.9% for amputation and 13.1% for blindness in the next 10 years; so still a much higher likelihood of them not happening.
Perhaps though this would be a bit of an exception, maybe the woman would already have some complications . This is indeed where the risk increases.
If she had peripheral vascular disease already then the risk went up to 41.6% for amputation; very much worse odds.
If she already had retinopathy, the risk for blindness increased to 31.2% ( Unfortunately, you don't know if you are going to be the 1/3 such people who go blind or the 2/3 that don't; )
Move that lady up the road to an area with a lower deprivation score; the same lady with existing peripheral vascular disease has a risk of amputation at 37.4%.( so slightly reduced )
With existing retinopathy that lady now has a risk for blindness of 24.5% (reduced by a bit more)
(I used this site plus a postcode side to choose my places; I won't say where they were but they were near to each other, one with a very high deprivation ranking and one in the bottom ie least deprived 10%.
http://apps.opendatacommunities.org/showcase/deprivation )
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Can anyone explain to me this in plain English?
If I enter my hba1c as 40 and it calculates my risk over 10 years, is this risk based on me maintaining a hba1c of 40 or does it presume that I am following the eatwell plate and possibly progressing to ill health?
If I enter my hba1c as 40 and it calculates my risk over 10 years, is this risk based on me maintaining a hba1c of 40 or does it presume that I am following the eatwell plate and possibly progressing to ill health?
SunnyExpat
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They have probably loaded it for the adverse affects they know the eatwell plate will cause.
Thanks. I don't know what the recommended diet was for the people who helped with the data gathering for this calculator. My D is ok at the moment, but there is still room for improvement so maybe I could skew my chances further
