Leprosy Mailing List – August 6th, 2007
Ref.: Numerators
and denominators should come from the same source
From: Post E., Wuerzburg,
Germany
Hallo Pran,
Thanks for your comment to my message
dated LML August 1st, 2007.
I reported an example just to demonstrate that aggregate rates
are not comparable when the aggregate denominator changes.
In the example I didn't change anything for the countries 1-6, except
that I excluded 1 country in the following year, and 2 countries in
the third year. Then I
called it year 1, year 2 and year 3.
For the countries mentioned, I just kept the number of new
cases constant (= all factors kept constant) so as to strengthen the
picture that by changing the aggregate denominator you get
non-comparable aggregate rates. In
reality, in this example, nothing changed, only some countries were
"omitted" from the reporting, while rates fluctuated
enormously. Quod era
demonstrandum.
I hope it is now clearer, indeed it was
abstract.
Groeten,
Erik
Erik
Post, MD MSc, Medical Advisor
German
Leprosy and Tuberculosis Relief Association
Mariannhillstr.
1-C, 97074 Wuerzburg, Germany
Tel:
+49 931 7948 113
Fax: +49 931 7948 160
Email: erik.post@dahw.de
Internet: www.dahw.de
