Probability of health state transition |
Methadone state |
Remain in methadone state* | λ = 0.114, γ = 0.643 | Weibull | BC MMTOS |
Multiplier: Episode 4† | 0.923 (0.033) | Normal | BC MMTOS |
Multiplier: Episode 5 | 0.965 (0.042) | Normal | |
Multiplier: Episode 6 | 0.952 (0.041) | Normal | |
Transition to relapse state | 95.9% | Beta | BC MMTOS |
Transition to abstinence state | 4.1% | | |
Diacetylmorphine state |
Remain in diacetylmorphine state* | λ = 0.061, γ = 0.761 | Weibull | NAOMI |
Multiplier: Episode 4‡ | 0.923 (0.033) | Normal | BC MMTOS |
Multiplier: Episode 5 | 0.965 (0.042) | Normal | |
Multiplier: Episode 6 | 0.952 (0.041) | Normal | |
Transition to relapse state§ | 37.0% | Dirichlet | Rehm et al. (44) |
Transition to abstinence state | 22.4% | | |
Transition to methadone state | 40.7% | | |
Relapse state |
Remain in relapse state* | λ = 0.091, γ = 0.672 | Weibull | BC MMTOS |
Multiplier: Episode 4 | 1.220 (0.048) | Normal | BC MMTOS |
Multiplier: Episode 5 | 1.350 (0.060) | Normal | |
Multiplier: Episode 6 | 1.442 (0.056) | Normal | |
Transition to treatment state | 1 | Fixed | |
Abstinence state |
Remain in abstinence state* | λ = 0.089, γ = 0.797 | Weibull | Termorshuizen et al. (12) |
Transition to relapse state | 1 | Fixed | |
Transition to death¶ |
Abstinence state, HIV negative | See Appendix 1, Table A1 | Fixed | Statistics Canada (32) |
Abstinence state, HIV positive, standardized mortality ratio, mean (SD) | 1.47 (1.07, 2.01) | Normal | ATCC (45) |
Relapse state, standardized mortality ratio, mean (SD) | 30.063 (3.169) | Normal | Spittal et al. (33) |
Methadone state, relative risk, mean (SD) | 0.350 (0.087) | Normal | Caplehorn et al. (6) |
Diacetylmorphine state, standardized mortality ratio, mean (SD) | 9.70 (0.17) | Normal | Rehm et al. (34) |
HIV seroconversion** |
Treatment state, mean (SD) | 0.0028 (0.0010) | Beta | Bayoumi et al. (38) |
Relapse state, mean (SD) | 0.0364 (0.0146) | Beta | |
Abstinence state, mean (SD) | 0.0007 (0.0001) | Beta | |
QALYs†† |
Methadone or diacetylmorphine state | 0.852 | MVN | NAOMI |
Relapse state | 0.750 | MVN | NAOMI |
Abstinence state, HIV negative | See Appendix 1, Table A15 | Beta | Johnson et al. (46) |
Abstinence state, HIV positive, mean (SD) | 0.77 (0.19) | Beta | Anis et al. (47) |
Monthly costs,‡‡ Can$ |
Drug treatment |
Methadone, mean (SD) | 329.38 (24.46) | Normal | NAOMI, BC PNET |
Diacetylmorphine, mean (SD) | 1415.21 (25.68) | Normal | NAOMI |
HIV infection | 28.30 | Fixed | Wood et al. (48) and Krentz et al. (49) |
Hepatitis C virus infection | 673.82 | Fixed | Butt et al. (50) and BC PNET |
Methadone or diacetylmorphine state§§ |
Health resource utilization, HIV positive | 72.10 | MVN | NAOMI |
Criminal involvement | 950.52 | MVN | NAOMI |
Criminal charges | 398.82 | MVN | NAOMI |
Relapse state§§ |
Health resource utilization, HIV positive | 695.98 | MVN | NAOMI |
Criminal involvement | 8981.28 | MVN | NAOMI |
Criminal charges | 590.05 | MVN | NAOMI |