Overview and Introduction: Chapter 7

Health… the sedimentation of society

Exercise

Table 7.1 from the book lists the major causes of mortality in England and Wales in the year 2010, their ICD codes, disease label and the cumulative chance of dying of each cause of death (in the first column as measured out of 1024). Thus a man or boy has about a 5.8% chance of dying of a disease not listed in the table and a woman or a girl an 8.3% chance (see the first two numbers in the first column of the table below for where those percentages come from).

We can use the first column, the "cumulative chance out of 1024", and a coin, to give each member of the class a cause of death at random, assuming that the patterns in the future are similar to those in 2010. The distribution of causes of death in the class should then reflect those in society as a whole.

To play the game each student needs a coin. Heads are '1' and tails are '0'. They will need to toss their coin 10 times to determine their allotted cause of death. This method is similar to that used in the exercise at the end of chapter 6. Begin with a chance of 1 out of 1024. Toss the first for the 1st time, if you get heads add 1, otherwise add nothing. Do this again a second time, but add 2 if you get heads, again nothing if you get tails. Do it again, adding 4 for heads; again, adding 8 for heads; again adding 16; again, adding 32; again, adding 64; again, adding 128, again, adding 256, and again, adding 512 if you get heads. Ten heads and your number is 1024 and you are dying of an external cause (other). There are different chances for men and women (use the rows marked M and F below).

This game may appear a little complex but all that it involves is in effect turning up to 10 tosses of a coin into a number between 1 and 1,024 to give a probability which can then be used to allocate a cause of death from Table 7.1. By reading down the first column until you come to your number or a number larger than it, it quickly becomes apparent which cause of death you have been allocated.

Here's a worked example. I start with the number 1 and toss, tails, heads, tails, heads, tails, heads, tails, heads, tails, heads. My score is 1+0+2+0+8+0+32+0+128+0+512 = 683. I decide I am male and look down the first column until I get to 767, the first number equal or greater than mine. I read across and see I am to die of "IX (other) Diseases of the circulatory system". Reading up to see what I have just skipped I work out that this will be a more obscure disease of my heart and blood vessels, but not Acute myocardial infarction (heart attack), Other heart diseases, Cerebrovascular diseases, or an Aortic aneurysm. Well, that doesn't sound too bad.

Having allocated each member of the class a cause of death at random, next work out which groups of causes are most numerous in your population - infectious diseases, cancers, diseases of the blood and so on. For the most common causes, see if you have people allocated similar causes within those groups. It is important to remember that these causes have been allocated at random. They mean nothing for the people specifically allocated a cause. Some congenital causes (which are mostly included in the first group) only kill young babies, for instance, and several causes largely only apply to either men or women. However, for the group as a whole the distribution should be interesting. Here are a series of questions you can ask:

  1. Are there causes that people are concerned about, for instance accidents or pneumonia, which no one in your class has been allocated? Is this because they are rare or because of chance? If you think it is chance, try another random allocation of the class. If you are very good at maths, work out how many allocations you would have to make, given the size of your class, on average, until these causes were allocated.
  2. What will kill the bulk of students in your class if they are representative of the population of England and Wales, and if future causes of death are distributed as they are now?
  3. Can you think of any reasons why your actual causes of death may be different from those allocated by this procedure, even if future causes of death are distributed as they are now?
  4. Which of the causes that have been allocated do you think students will be less likely to die of in the future and which more likely, and why?
  5. Given the maps above and the location in which you are playing this game (if that is in Britain) how might your local geography influence these chances?
  6. Finally, the table also includes information about the rates of death per million at particular ages. Ignoring the first general category, of "not listed below", what does kill most people of your group's average age?

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Related material for Chapter 7:

All available data and further material can be found in the Data section.