Epidemiology module of practical skills for mbbs student

Practical exercise

Role of statistical testing in research

from The Epidemiology of tuberculosis in gold miners with silicosis. Cowie RL. Am J Respir Crit Care Med 1994; 150:1460-1462.

These investigators carried out a 7 year prospective study of 1153 South African gold miners. At the start of the study, 818 of the miners had silicosis and 335 did not. Each miner was tested for active tuberculosis each year for the 7 years of follow-up. The investigators were interested in knowing if miners with silicosis were more likely to develop tuberculosis than those without silicosis.
Results (at the end of 7 years)