More numbers
Jul. 4th, 2019 01:19 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
lnrThis post is mostly number crunching, there's a summary version on Twitter addressed at CR_UK:
https://twitter.com/lnr_blair/status/1146772191796764672
OK, so normally you'd do a more complicated sum over several years of data, but at it's most basic the PAF (population attributable factor) is defined as:
(incident rate in total pop. - incident rate in unexposed pop.) / incident rate in total pop.
The figures know for Kidney cancer:
Total incidents: 12900
PAF estimate: 23.8%
Population:
Total population: 65 million
Total pop not overweight: 23.8 million (33.6%)
Total pop overweight = 42.1 million (63.4%)
Playing with all those figures, we can work out the total rate of incidence directly, and use that to deduce the rate in the unexposed population, and we can then deduce the number of people with Kidney Cancer who were "unexposed" to obesity:
Approx number of not-overweight people diagnosed: 3592
So of 12900 Bowel cancer cases 3592 were in thin people, 9308 were in overweight people. If overweight people got cancer at the same rate as the non-exposed people (0.0151%), we'd expect 6221 to get bowel cancer. So we estimate that 3087 extra people got cancer linked to their exposure. (The actual figure was 2941 - pretty close considering the very approximate pop. figures).
Rate in total population = 0.0198%
Rate in unexposed population = 0.0151%
Rate in overweight ppl = 0.0226%
https://twitter.com/lnr_blair/status/1146772191796764672
OK, so normally you'd do a more complicated sum over several years of data, but at it's most basic the PAF (population attributable factor) is defined as:
(incident rate in total pop. - incident rate in unexposed pop.) / incident rate in total pop.
The figures know for Kidney cancer:
Total incidents: 12900
PAF estimate: 23.8%
Population:
Total population: 65 million
Total pop not overweight: 23.8 million (33.6%)
Total pop overweight = 42.1 million (63.4%)
Playing with all those figures, we can work out the total rate of incidence directly, and use that to deduce the rate in the unexposed population, and we can then deduce the number of people with Kidney Cancer who were "unexposed" to obesity:
Approx number of not-overweight people diagnosed: 3592
So of 12900 Bowel cancer cases 3592 were in thin people, 9308 were in overweight people. If overweight people got cancer at the same rate as the non-exposed people (0.0151%), we'd expect 6221 to get bowel cancer. So we estimate that 3087 extra people got cancer linked to their exposure. (The actual figure was 2941 - pretty close considering the very approximate pop. figures).
Rate in total population = 0.0198%
Rate in unexposed population = 0.0151%
Rate in overweight ppl = 0.0226%
