Disease Detective B/C

[summit]

Can someone check the validity of the problem situation (outbreak of Norovirus) in this test? http://scioly.org/w/images/f/f2/Dis.pdf
The answer key says it uses a case-control test, however (http://scioly.org/w/images/b/b3/Dis-sol.pdf) all of the details of the outbreak seem to indicate that it should use a cohort test.

Thanks!

We've been wondering the same thing. Thanks for asking!

[Starapollo1]

Has anyone found any good sources regarding the math portion? That is my section for this event, and though competent, I do at times struggle with taking the information in the text and figuring the relative risk. If anyone has any sites/sources (besides what’s on sonic.org) that would be much appreciated!

[akatsuki9]

Believe it or not, everybody who I asked recommended wikipedia... It's actually pretty good!

[SciBomb97]

The only thing about wikipedia is that the science articels are all written by nerds who have too much time to annoy other nerds with their profoundly ridiculous vocabulary.
You should try reading the stuff about physics. They're all written by professors/ they've been edited by professors who want us to despair at their terrible choice of words.
It's their way of saying "Wikipedia sucks"

[Flavorflav]

Can someone check the validity of the problem situation (outbreak of Norovirus) in this test? http://scioly.org/w/images/f/f2/Dis.pdf
The answer key says it uses a case-control test, however (http://scioly.org/w/images/b/b3/Dis-sol.pdf) all of the details of the outbreak seem to indicate that it should use a cohort test.

Thanks!

Yeah, it should be a cohort study. Presumably the writer was misled by the fact that most investigations of food poisoning have to use the case-control design, because you usually start with a bunch of sick people and have to find out if they were more likely to have eaten the pot de creme. In this case, they have complete information about who ordered the pot de creme and who did not. Those who did form a cohort, defined by exposure. In a case-control study, cases are defined by developing the disease. They should use relative risk instead of odds ratio, too, because they have attack rates.

ETA: it probably wouldn't have been salmonella, either. Mode incubation period is usually close to 20 hours, so symptoms would not have hit overnight.

[summit]

Yeah, it should be a cohort study. Presumably the writer was misled by the fact that most investigations of food poisoning have to use the case-control design, because you usually start with a bunch of sick people and have to find out if they were more likely to have eaten the pot de creme. In this case, they have complete information about who ordered the pot de creme and who did not. Those who did form a cohort, defined by exposure. In a case-control study, cases are defined by developing the disease. They should use relative risk instead of odds ratio, too, because they have attack rates.

Not the OP, but thank you for the response!

[rkoopma2]

Does anyone know any good online (free) disease detective resources. My coach has apparently lost the epidemiology books I've been using the last three years. the links on the national website don't really have anything good except for the "principles of epidemiology in public health practice" book that I've already read.

[SirBobo]

Does anyone know any good online (free) disease detective resources. My coach has apparently lost the epidemiology books I've been using the last three years. the links on the national website don't really have anything good except for the "principles of epidemiology in public health practice" book that I've already read.

CDC EXCITE! has a lot of practice tests and material. You should look there and it's FREE!. Hope this helped!

[rkoopma2]

Does anyone know any good online (free) disease detective resources. My coach has apparently lost the epidemiology books I've been using the last three years. the links on the national website don't really have anything good except for the "principles of epidemiology in public health practice" book that I've already read.

CDC EXCITE! has a lot of practice tests and material. You should look there and it's FREE!. Hope this helped!

I've looked at the page, but I haven' t really found anything about biases/modifiers/confounding. I understand division C is supposed to have more question on this sort of stuff????

Also how much specific disease info do you think we need? In middle school I got away with none - just epidemiology - on my cheat sheet. The only tests we really had with disease info were a few questions on tests at invitationals.

[Infinity Flat]

Does anyone know any good online (free) disease detective resources. My coach has apparently lost the epidemiology books I've been using the last three years. the links on the national website don't really have anything good except for the "principles of epidemiology in public health practice" book that I've already read.

CDC EXCITE! has a lot of practice tests and material. You should look there and it's FREE!. Hope this helped!

I've looked at the page, but I haven' t really found anything about biases/modifiers/confounding. I understand division C is supposed to have more question on this sort of stuff????

Also how much specific disease info do you think we need? In middle school I got away with none - just epidemiology - on my cheat sheet. The only tests we really had with disease info were a few questions on tests at invitationals.

About 1/8 of my sheet is specific disease info, but honestly, that's a little much. You really only NEED information on the most commonly asked about food-borne illnesses: E. Coli, Salmonella, Botulism, &c.

As far as the biases/modifiers/confounding stuff, I've never seen a test that didn't have questions on that beyond a very basic level.