Question

A population of 9,000 men 45 years of age or older was examined in January 2010. Of these, 5,000 lived in areas where they were exposed to high levels of air pollution and 4,000 lived in areas with low levels of air pollution. At the initial examination, 150 cases of chronic bronchitis were discovered; 100 among participants living in areas with high levels of air pollution and 50 among those in areas with low pollution. All the men initially examined who did not have chronic bronchitis were available for subsequent repeated examinations during the next 5 years. These examinations revealed 320 new cases of chronic bronchitis and of those 260 lived in areas with high levels of air pollution while 60 lived in areas with low pollution levels. What is prevalence of chronic bronchitis among men 45 years of age or older who lived in areas with high levels of air pollution in January 2010?

A. 15.2 per 1000

B. 52 per 1000

C. 20.0 per 1000

D. 15.0 per 1000

E. 5.0 per 1000

Answer 1

Here people living in low level pollution areas= 4000

total new cases of chronic bronchitis = 320

new case of chronic bronchitis in high pollution areas = 260

low pollution areas - 50

5,000 lived in areas where they were exposed to high levels of air pollution

Prevalence rate = 260/ (5000 - 50) * 100 = 5.2% = 52 per 1000

prevalence of chronic bronchitis among men 45 years of age or older who lived in areas with high levels of air pollution in January 2010 52 per 1000 (option B)