Question

A population of 9000 men and women, aged 45, were examined on January 1st, 2005. Of these people, 6,000 were exposed to toxins in the local water supply and 3,000 were not. At the time of this exam, 90 cases of peptic ulcer diseases were discovered. 60 of these cases were among those exposed to toxins in their local water. all the people at the initial exam who were free from peptic ulcer disease were followed with repeat exams over the year (Dec 31, 2005). This study revealed 268 new cases, and of these, 238 cases among those exposed to toxins in their local water

1. calculate the period prevalence per 1,000 people of peptic ulcer disease for 2005 (01/1/05-12/31/05).

Among the exposed:

Among the non-exposed:

2. Calculate the incidence rate of 2005 per 1,000 people of peptic ulcer disease

Among Exposed:

Among Non-Exposed.

Can you explain how you did so for each, why? I'm confused about why you add 268+90 for the last one.

Answer 1

10 Among the people who are exposed to toxins 60+238 x 1000 = 49.7 (49.66) 6,000 * Among the people who are non exposed to toxing : 30+30 x1000 = 20. 3000 people who are exposed to toring 238 O x 1000 = 40.06. (5,940 because 60 are 7 15,940 Terposed = 6000=60 = 5940) Among the people who are not exposed to toxins = 30 x 1000 hon exposed 3000 £307 2,970 | exposed = 3000-30=2970) = 10.10