In a cohort of Italian asbestos cement workers, the 2576 men followed contributed 63 899 person-years of observation, and the 777 women contributed 23 267 person-years of observation. There

1. In a cohort of Italian asbestos cement workers, the 2576 men followed contributed 63 899 person-years of observation, and the 777 women contributed 23 267 person-years of observation. There were 55 cases of mesothelioma among the men and 17 cases of mesothelioma among the women. Use women as your referent group
Incidence rate per 100,000 person-years for mesothelioma among men. (55 cases / 63,899 person-years) x 100,000 = 86.09
Incidence rate per 100,000 person-years for mesothelioma among women. (17 cases / 23,267 person-years) x 100,000 = 73.16
A. Calculate an incidence rate ratio that compares the incidence of mesothelioma between the exposure groups. Do not round any portion of your calculations until the end. Round to the hundredths place.
B. Provide an interpretation for the IRR that you calculated. (1 point)
The IRR of 1.05 suggests that the incidence rate of mesothelioma is slightly higher among men compared to women, with men having a 5% higher incidence rate.
Part 2
2. Data from a case-control study of 285 esophageal cancer cases and 975 community-based controls are shown below. Detailed dietary data were obtained by interview. This example addresses the relation between alcohol consumption (categorized as none, 1-50 g per day, and 50-80 grams per day) and esophageal cancer.
Daily Alcohol Consumption Cases Controls
0 grams per day 106 666
1 – 50 grams per day 85 200
50 – 80 grams per day 94 109
A. Using the group who consumed 50 – 80 grams of daily alcohol on average as the referent group, calculate odds ratios comparing the odds of getting esophageal cancer for the various levels of alcohol consumption.
B. Provide an interpretation for each OR that you calculated in part a.
C. Based on your calculations, is there perhaps a causal relationship between alcohol consumption and esophageal cancer? What causal “criteria” are met based on the study design and study findings?