model {
thetaN <- 2 # expected lifetime without transplant
thetaT ~ dbeta(8,2) # probability of surviving operation
thetaP ~ dnorm(5,1) # expected survival post-transplant (mean 5, sd 1)
thetaC ~ dnorm(3000,0.000001)
# expected cost per year (mean 3000, sd 1000)
E.c <- (20000 + thetaC*thetaT*thetaP)/1000
# expected additional cost of transplant
# in thousands of pounds
E.e <- thetaT*thetaP - thetaN
# expected total additional survival
ICER <- E.c/E.e # incremental cost-effectiveness ratio
for (i in 1:21) {
K[i] <- (i-1)*5
INB[i] <- E.e*K[i] - E.c
Q[i] <- step(INB[i])
}
}

node mean sd MC error 2.5% median 97.5% start sample
E.c 31.98 5.097 0.01578 23.5 31.47 43.35 1 100000
E.e 1.995 1.007 0.003094 0.09311 1.972 4.027 1 100000
ICER 15.05 1113.0 3.702 7.189 15.98 84.68 1 100000
INB[1] -31.98 5.097 0.01578 -43.34 -31.47 -23.5 1 100000
INB[2] -22.0 4.586 0.01494 -29.82 -22.44 -11.89 1 100000
INB[3] -12.03 8.173 0.026 -26.35 -12.6 5.507 1 100000
INB[4] -2.056 12.78 0.04009 -25.42 -2.626 24.44 1 100000
INB[5] 7.918 17.62 0.05493 -24.76 7.299 44.0 1 100000
INB[6] 17.89 22.55 0.07004 -24.22 17.21 63.82 1 100000
INB[7] 27.87 27.51 0.08527 -23.66 27.1 83.62 1 100000
INB[8] 37.84 32.5 0.1006 -23.16 37.0 103.6 1 100000
INB[9] 47.81 37.5 0.1159 -22.63 46.9 123.6 1 100000
INB[10] 57.79 42.51 0.1313 -22.16 56.76 143.6 1 100000
INB[11] 67.76 47.52 0.1467 -21.68 66.63 163.7 1 100000
INB[12] 77.74 52.54 0.1621 -21.2 76.52 183.8 1 100000
INB[13] 87.71 57.56 0.1775 -20.71 86.39 203.8 1 100000
INB[14] 97.68 62.59 0.193 -20.26 96.24 224.1 1 100000
INB[15] 107.7 67.61 0.2084 -19.82 106.1 244.3 1 100000
INB[16] 117.6 72.64 0.2238 -19.29 116.0 264.4 1 100000
INB[17] 127.6 77.67 0.2393 -18.85 125.9 284.4 1 100000
INB[18] 137.6 82.69 0.2547 -18.35 135.8 304.4 1 100000
INB[19] 147.6 87.72 0.2702 -17.97 145.6 324.6 1 100000
INB[20] 157.5 92.75 0.2856 -17.49 155.5 344.6 1 100000
INB[21] 167.5 97.78 0.3011 -17.01 165.3 364.7 1 100000
Q[1] 0.0 0.0 3.162E-13 0.0 0.0 0.0 1 100000
Q[2] 1.3E-4 0.0114 3.809E-5 0.0 0.0 0.0 1 100000
Q[3] 0.07902 0.2698 8.593E-4 0.0 0.0 1.0 1 100000
Q[4] 0.4203 0.4936 0.001531 0.0 0.0 1.0 1 100000
Q[5] 0.6614 0.4732 0.001498 0.0 1.0 1.0 1 100000
Q[6] 0.7799 0.4143 0.001334 0.0 1.0 1.0 1 100000
Q[7] 0.8415 0.3652 0.00121 0.0 1.0 1.0 1 100000
Q[8] 0.8777 0.3276 0.001022 0.0 1.0 1.0 1 100000
Q[9] 0.9 0.3 9.632E-4 0.0 1.0 1.0 1 100000
Q[10] 0.9157 0.2778 8.903E-4 0.0 1.0 1.0 1 100000
Q[11] 0.9265 0.2609 8.315E-4 0.0 1.0 1.0 1 100000
Q[12] 0.9339 0.2484 7.917E-4 0.0 1.0 1.0 1 100000
Q[13] 0.9398 0.2378 7.583E-4 0.0 1.0 1.0 1 100000
Q[14] 0.9447 0.2286 7.232E-4 0.0 1.0 1.0 1 100000
Q[15] 0.9484 0.2212 7.011E-4 0.0 1.0 1.0 1 100000
Q[16] 0.9514 0.215 6.871E-4 0.0 1.0 1.0 1 100000
Q[17] 0.954 0.2095 6.867E-4 0.0 1.0 1.0 1 100000
Q[18] 0.9562 0.2047 6.907E-4 0.0 1.0 1.0 1 100000
Q[19] 0.958 0.2006 6.698E-4 0.0 1.0 1.0 1 100000
Q[20] 0.9595 0.1971 6.466E-4 0.0 1.0 1.0 1 100000
Q[21] 0.9607 0.1942 6.383E-4 0.0 1.0 1.0 1 100000