2. A randomized, twoarm trial is conducted comparing a control treatment (A) to a experimental treatment (B). The primary outcome is all~cause mortality. (a) (10 pts] After completion of the trial we observe the following table: Subjects Deaths Personyears followup A 500 24 1 835 B 500 219 876 Assume exponential survival and compute the hazard ratio for treatment B versus treatment A. (b) (10 pts) It is noted that many subjects do not adhere to their assigned treatment and when subjects are classied by their level of adherence, we observe the following table: Adherence Subjects Deaths Personwyears followup A 2) 80% 110 52 180 50%80% 240 153 352 g 50% 150 36 303 B > 80% 145 51 262 50%80% 280 148 463 g 50% 75 20 151 Compute hazard ratios for treatment E versus treatment A for subjects within each stratum based on adherence {> 80%, 50%80%, S 50%). (c) (10 pts} Note the differences between the analyses in part (b) and the overall comparison in part (a). What do each of these analyses tell us about the causal effect of treatment on mortality