Of 2,872 persons who had received radiation treatment in childhood because of an enlarged thymus, cancer of the thyroid developed in 24 and a benign thyroid tumor developed in 52. A comparison group consisted of 5,055 children who had received no such treatment (brothers and sisters of the children who had received radiation treatment). During the follow up period, none of the comparison group developed thyroid cancer, but benign thyroid tumors developed in 6. Calculate the relative risk for benign thyroid tumors: The answer is 15.2.
The textbook does not show the calculations, a word table showing the numerical values for a,b,c and d, related the formula for the measure of association (OR,RR,PAR,etc) or a stated summary statement describing the relationship of the data and measure of association i.e. Those who never eat raw eggs have 1.75 times as much risk(higher incident) as those who ate raw eggs almost daily (RR+1.75)
Risk for patients who recieved radiation treatment in childhood of developing thyroid tumour = 52/2872 ( ...