Is it possible that the health impact incidence exceeds that total number of population involved?


If not/yes? Why is this so?

(ThaoPham) #2

It is impossible that health impact incidence exceeds total number of population involved. If you look at a key equation to estimate health impact (using in BenMAP or other manual), incidence is a product of population, baseline incidence, Beta (health impact function) and Delta (concentration change). Baseline incidence and Beta is often far less than 1, so in calculation process, incidence should be far less than total number of population. In reality, it is also not realistic to have incidence exceeds total number of population involved.

Hope this help!

Thao Pham


Even if I used the study of Ostro et. al 1987 with work loss days as a health endpoint? I run this in benmap together with the study of Babin et al. 2007 and Ito 2003 on Hospital Admission, Asthma and Hospital Admission, Congestive Heart Failure respectively and their results did not exceed the total population only the study of Ostro exceeded.

Thank you very much for your help.

(Josh Bankert) #4

It is possible for health outcome estimates to exceed the total population. In fact, most individuals likely miss more than one day per year (work loss day) due to illness or injury. Thus, incidence would be greater than one when expressed as the rate per person per year. However, as a whole, most work loss days are likely unrelated to ambient air pollution. When you inspect your baseline incidence, how does the value compare to your population?