Question

.

Case Study The following table shows the number of colon cancer deaths and person-years of risk by the frequency of aspirin for males and females. Table 1. Rates of death from colon cancer, according to frequency of aspirin use in the coh patients with illness at enrolment were excluded. Aspirin Use (times per month) 0 1-15 -16 Men Number of Deaths 378 184 127 85 Person-years at risk Death rate per 100.000 Rate ratlo 646,346436,620 389,083 201,636 100 Women Number of Deaths 284 157 100 73 705.064 671927505.854 265,424 Person-years at risik Death rate per 100,000 Rate ratio 100 Calculate the death rates and the rate ratios for each of the aspirin-use categories in the above table 2 Given the resuits in this table, what is your conclusion about the sssociation between the use of aspirin and fatal colon cancer?

Answer 1

		Aspirin use (times per month)
		0	<1	1-15	>16
Men	Number of Deaths	378	184	127	85
	Person-year at risk	646,346	486,620	389,083	201,636
	death per 100,000	58.48	37.81	32.64	42.16
	death rate per 100,000	0.05848%	0.03781%	0.03264%	0.04216%
Women	Number of Deaths	284	157	100	73
	Person-year at risk	705,064	671,927	505,854	265,424
	death per 100,000	40.28	23.37	19.77	27.5031
	death rate per 100,000	0.04028%	0.02337%	0.01977%	0.02750%

death rate per 1,00,000 is = $\tfrac{number of death*100,000}{person-year at risk}$