1. Compute the crude RR and stratum-specific RR estimates (age-adjusted RR) for these data collected in a cohort study. CHD = coronary heart disease; Cat = elevated catecholamine level. Age yes Cat = no Total 1 19 20 CHD = no 7 255 262 Total 8 274 282 Age 30-39 CHD = yes Stratum-Specific RR: Cat = yes Cat = no 3 7 10 CHD = no 14 52 66 Total 17 59 Total 76 Age 40-40 Stratum-specific RR: Cat = yes Cat = no Total CHD = yes 8 16 24 CHD = no 30 107 137 Total 38 123 161 Age > 50 CHD = yes Total Stratum-specific RR: Cat = yes Cat = no 14 5 19 CHD = no 44 27 71 Total 32 90 Crude RR CHD = yes CHD=no Total Crude RR: Cat = yes Cat = no Total Is there any evidence that age is a confounder in the Cat-CHD association? Why or why not? Is there any evidence that age is an effect modifier in the Cat-CHD association? Why or why not? 1. Compute the crude RR and stratum-specific RR estimates (age-adjusted RR) for these data collected in a cohort study. CHD = coronary heart disease; Cat = elevated catecholamine level. Age yes Cat = no Total 1 19 20 CHD = no 7 255 262 Total 8 274 282 Age 30-39 CHD = yes Stratum-Specific RR: Cat = yes Cat = no 3 7 10 CHD = no 14 52 66 Total 17 59 Total 76 Age 40-40 Stratum-specific RR: Cat = yes Cat = no Total CHD = yes 8 16 24 CHD = no 30 107 137 Total 38 123 161 Age > 50 CHD = yes Total Stratum-specific RR: Cat = yes Cat = no 14 5 19 CHD = no 44 27 71 Total 32 90 Crude RR CHD = yes CHD=no Total Crude RR: Cat = yes Cat = no Total Is there any evidence that age is a confounder in the Cat-CHD association? Why or why not? Is there any evidence that age is an effect modifier in the Cat-CHD association? Why or why not