Medical statistics: incidence

[Function]

Hello everyone

 

I need a quick confirmation on something.

 

(For those who might wonder: this is a question concerning the paper I'm writing on the differences in epidemiology of influenza type A(H1N1)pdm09 during the pandemic of 2009-2010, in Europe and Africa.)

 

In an article, given is the estimated number of inhabitants in Rwanda: 10.4 million. Given is also that 494 cases of this influenza have been recorded between October 2009 and 31 May 2010 = 8 months = 2/3 years

 

I was wondering if there is something that allows me to calculate the incidence rate during that period as follows, considering that everyone is at risk of contracting influenza:

 

8 months --> 494/10,400,000 ~ 4,75 per 100 000 persons per 8 months

1 month --> 494/(8*10,400,000) ~ 0,59375 per 100 000 persons per month

12 months --> 12*494/(8*10,400,000) ~ 7,125 per 100 000 PY

 

Can this somehow be correct (the calculation of the incidence - of course the number itself isn't exact due to limitations of statistical data in Africa etc.)?

Please tell me it can, because I'm starting to get depressed (I can't find any good article on incidence of that specific influenza during that pandemic period in Africa, except for South Africa and Reunion Island, so this was the only way to find a third incidence, which is necessary).

 

Thanks!

 

F.

Edited March 6, 2015 by Function

[MonDie]

I would qualify it with "at least" since some cases may go unrecorded. You could try to estimate what percentage of cases go unrecorded, but I can't help you with that.

Edited March 11, 2015 by MonDie

[Function]

That's what I'm about to include in the discussions section. Especially in Africa, where the incidence is much, much lower than Europe, many cases might've gone lost.

[CharonY]

Actually this is tricky. Extrapolating to 12 months is dangerous if you do not know whether incidence rate is stable throughout the year (which it typically is not). But if you do not find any data it is definitely a discussion point. Rather unfortunately it seems that the WHO also struggled with the dearth of data, so it could be that your report will havet to be somewhat inconclusive...

Edited March 12, 2015 by CharonY

[Function]

I will, of course, not neglect the 'unstable' course influenza takes and had taken during that pandemic, but in the results section of my paper, I can, however, only implement results as they can be strictly derived from the data used in the articles I'm referring to.

 

In the dicsussions section, all these things will be taken in account.

[CharonY]

Yes, and assuming you normalize to a year you would have to add that part in the methods section anyway.The alternative would to limit the analysis to the time frame where you have data for every region, if possible.

[Function]

Yes, and assuming you normalize to a year you would have to add that part in the methods section anyway.The alternative would to limit the analysis to the time frame where you have data for every region, if possible.

 

Could do that, too. Thanks for the input