A total of 850 insulation workers employed between 1940 and 1945 was identified from the personnel records of three large insulation manufacturing plants in the Midwestern U. S. in 1980. During the period 1940-1980, 28 deaths from lung cancer were discovered among the workers. Only eight lung cancer deaths, however, were reported among a comparable group of 800 coworkers who did not work with insulation during the same time period. The investigators had hypothesized that exposure to the insulation material increases the risk of lung cancer. Required:
Which epidemiology study design best represents this description?