Question

1. The following table shows the number of colon cancer deaths and person-years of risk by the frequency of aspirin for males. 

   Table 1. Rates of death from colon cancer, according to the frequency of aspirin use in the cohort before patients with illness at enrollment were excluded.

    

   	Aspirin Use (times per month)
   		0	<1	1-15	>16
   Men	Number of Deaths	378	184	127	85
   	Person-years at risk	646,346	486,620	389,083	201,636
   	Death rate per 100,000
   	Rate ratio	1.00

    

   Calculate the death rates and the rate ratios for each of the aspirin-use categories in the above table.

    

3 points   

QUESTION 2

1. The following table shows the number of colon cancer deaths and person-years of risk by the frequency of aspirin for females. 

   Table 1 (extended). Rates of death from colon cancer, according to the frequency of aspirin use in the cohort before patients with illness at enrollment were excluded.

   		Aspirin Use (times per month)
   		0	<1	1-15	>16
   Women	Number of Deaths	284	157	100	73
   	Person-years at risk	705,064	671,927	505,854	265,424
   	Death rate per 100,000
   	Rate ratio	1.00