Question

The data presented in Problem 7 are analyzed using multiple linear regression analysis and the models are shown here. In the models, the data are coded as 1 = new medication and 0 = standard medication, and age 65 and older is coded as 1 = yes and 0 = no. ŷ = 53.85 − 23.54 (Medication) ŷ = 45.31 − 19.88 (Medication) + 14.64 (Age 65 +) ŷ = 45.51 − 20.21 ( Medication ) + 14.29 ( Age 65 + ) + 0.75 ( Medication × Age 65 + ) Patients < 65 : ˆ y = 45.51 − 20.21 ( Medication ) Patients 65 + : ˆ y = 59.80 − 19.47 ( Medication ) Does it appear that there is effect modification by age? Justify your response using the preceding models.

Based on your answers to Problem 8 and Problem 9, how should the effect of the treatment be summarized? Should results be reported separately by age group or combined? Should the effect of treatment be adjusted for age? Justify your response using the models presented in Problem 9.

Answer 1