CFL (Can Football League) & ALS

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rolark

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Joined
Apr 20, 2006
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27
Reason
Loved one DX
Diagnosis
03/2006
Country
CA
State
Ontario
City
Sharon
Hi Tim,

I heard the same report on CBC. Statistically the reporter is comparing apples to oranges and in fact it also appeared that Tony Proudfoot (PALS) and Angela Genge, who is undertaking the study, also are statistically confused. The 2 per 100,000 figure is an estimate of the incidence of ALS, i.e. the number people in a population who have it at a point in time. Then the reporter compares this to the fact that 8 in 15,000 ex-CFL players have contracted ALS and suggests that the rate is about 8/15,000 or 53 per 100,000. But this is not the incidence of the CFL population, it is simply how many people of the 15,000 over X years who have contracted ALS. So far from Ms Genge's comment that Tony Proudfoot is "exactly right", he is in fact quite wrong.

Another way to look at it (this has been discussed previously on various threads) is to look at the lifetime chance of getting ALS. This is easily calculated by dividing the number of people who die from ALS in the USA every year (estimated at 5500) into the total number of deaths in a year. Divide the 5500 into the number of deaths from all causes (2,448,000 in 2003) and you get 2.2467 deaths per 1000 from ALS or 1 per 445. This last statistic is the lifetime chance of dieing from ALS. This gives a more understandable statistic to me than the 2/100,000 incidence that is normally quoted. I don't know how long a period the study covers but it must be more than 50 years and therefore many or most of the ex-footballers would have reached the prime age for developing the disease, i.e. 40-60 years. Suddenly 8 per 15,000 doesn't seem so out of line with the regular population. One would expect out of a population of 15,000 that 33 would eventually die of ALS anyway, not related to football.

As always, the devil is in the details and Ms Genge will have to sort out the time span covered and the ages of all the persons in the CFL population.
 
What's the old saying? Figures don't lie but liars sure can figure. Makes you wonder when they play with the numbers.
AL.
 
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