Cycle number State A State B State C State D 1000 0 0 0 0.721-721 0.202 209 0.087-07 721 202 67 10 0.01067 0.721-520 0.087:48 05-SC'0 D1 000' 0012 #2 0.601-117 2 520 263 181 36 Fig. 2.4 Illustration of the first two cycles of a cohort simulation for monotherapy for the Markov model used in the case study.State at start of cycle State at end of cycle 1. Annual transition probabilities (a) Monotherapy State A State B State C State D State A 0.721 0.202 0.067 0.010 State B 0.000 0.581 0.407 0.012 State C 0.000 0.000 0.750 0.250 State D 0.000 0.000 0.000 0.000 (b) Combination therapy State A State B State C State D State A 0.858 0.103 0.034 0.005 (1 - sum) (0.202 x RR) (0.067 x RR) (0.010 x RR) State B 0.000 0.787 0.207 0.006 (1 - sum) (0.407 x RR) (0.012 x RR) State C 0.000 0.000 0.873 0.127 (1 - sum) (0.25 x RR) State D 0.000 0.000 0.000 1.000 2. Annual costs Direct medical (1701 f1774 16948 Community f1055 f1278 f2059 II Total E2756 f3052 19007 RR, relative risk of disease progression. Estimated as 0.509 in a meta-analysis. The drug costs were f2278 (zidovudine) and f2086 (lamivudine)