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. 2017 Sep 26;66(5):765–777. doi: 10.1093/cid/cix832

Table 1.

Input Parameters for the Dynamic Compartmental Human Immunodeficiency Virus Transmission Model

Description Value Source
Number of individuals in susceptible compartment i at time t (initial [1996]a value) 2.64M [14, 20, 21, 22]
Number of individuals in HIV-infected (undiagnosed) compartment i at time t (initial value) 3694 [14, 22, 23]
Number of individuals in HIV-diagnosed compartment i at time t (initial value) 3844 [14, 22, 23]
Number of individuals in HIV treatment compartment i at time t (initial value) 0 [14, 22, 23]
Number of individuals in HIV off-treatment compartment i at time t (initial value) 0 [14, 22, 23]
Monthly entry rate of individuals into compartment i Time-varying [20]
Average duration uninfected individuals in compartment i remain “identified” after screening 12 months Assumption
Monthly HIV screening rate for individuals in compartment i Figure 1 [1]
 High risk (PWID, MSM/PWID) (multiplier) 2.6 [24]
Total sufficient contact rate Time-varying [3–6, 16, 21, 25, 26, 27–56]
 Mortality and maturation rate for individuals in compartment i
 Monthly mortality rate: heterosexual (susceptible) 0.00027 [57]
 Monthly mortality rate: MSM (susceptible) 0.00034 [57]
 Monthly mortality rate: PWID (susceptible) 0.00238 [27]
 Monthly mortality rate: MSM/PWID (susceptible) 0.00246 [27]
 Monthly mortality rate: heterosexual (infected/diagnosed)
  CD4: ≥500 0.00079 [58]
  CD4: 350–499 0.00079 [58]
  CD4: 200–349 0.00136 [59]
  CD4: <200 0.00853 [18]
 Monthly mortality rate: MSM (infected/diagnosed)
  CD4: ≥500 0.00045 [28]
  CD4: 350–499 0.00045 [58]
  CD4: 200–349 0.00175 [59]
  CD4: <200 0.00853 [18]
 Monthly mortality rate: PWID, including MSM/PWID (infected/diagnosed)
  CD4: ≥500 0.00250 [58]
  CD4: 350–499 0.00250 [58]
  CD4: 200–349 0.00357 [59]
  CD4: <200 0.00856 [18]
 Monthly mortality rate: on ART (×1000–1) Time-varying [14, 22, 23]
 Non-PWID
  CD4: ≥500 0.474 (1996); 0.399 (2010)
  CD4: 350–499 0.608 (1996); 0.541 (2010)
  CD4: 200–349 1.167 (1996); 1.043 (2010)
  CD4: <200 8.259 (1996); 7.883 (2010)
 PWID
  CD4: ≥500 0.973 (1996); 0.833 (2010)
  CD4: 350–499 1.181 (1996); 1.078 (2010)
  CD4: 200–349 2.557 (1996); 2.354 (2010)
  CD4: <200 8.288 (1996); 8.021 (2010)
 Monthly maturation rate 0.00125 [20]
Symptom-based monthly case finding rate for infected individuals in compartment i
 Low risk (CD4: 200–349) 0.00874 [60]
 High risk (CD4: <200) 0.01842 [60]
HIV disease progression rate for individuals not on ART [19, 60–62]
 CD4: ≥500 to CD4: 350–499 0.02209
 CD4: 350–499 to CD4: 200–349 0.02209
 CD4: 200–349 to CD4 <200 0.02209
 CD4: <200 to death 0.00250
HIV disease progression rate for individuals on ART in compartment i Supplementary Materials, Figure A6 [14, 22, 23]
Rate of ART discontinuation Figure 2, panels E and F [14, 22, 23]
Probability of direct ART initiations immediately after diagnosis Supplementary Materials, Figure A4 [14, 22, 23]
Rate of individuals from diagnosed compartment i initiating antiretroviral treatment Figure 2, panels A and B [14, 22, 23]
Rate of ART reinitiation among those who had discontinued treatment Figure 2, Panels C and D [14, 22, 23]
Indicator variable for eligibility for HIV treatment initiation Time-varying [63, 64, 65–71]
 1996–1997 CD4 <500
 1998–2001 CD4 <350
 2002–2003 CD4 <200
 2004–2007 CD4 <350
 2008–2010 CD4 <500
 Post-2011 All CD4
HIV transmission parameter
Needle-sharing parameters
Number of injections (monthly) at baseline 19.5 [21, 26]
Reduced injections due to opioid agonist treatment 0.75 [27, 72]
Probability of shared injection at baseline 0.21 [21, 28]
Probability of transmission per shared injection: CD4 >500 0.002 [27, 29, 30]
Probability of transmission per shared injection: CD4: 350–499 0.002
Probability of transmission per shared injection: CD4: 200–349 0.003
Probability of transmission per shared injection: CD4 <200 0.003
Reduced probability of transmission on ART 0.9 [4]
Homosexual sex parameters
No sexual partners (annual) 2.7 [16, 21, 31]
Condom use probability 0.5 [25, 32–36]
Probability of transmission: CD4: >500 0.04 [16, 37–40]
Probability of transmission: CD4: 350–499 0.04
Probability of transmission: CD4: 200–349 0.05
Probability of transmission: CD4: <200 0.1
Reduced probability of transmission on ART 0.96 [6]
Decreased number of sexual partners due to diagnosis 0.5 [41–44
Condom effectiveness 0.9 [45]
Heterosexual sex parameters
No sexual partners: MSM 0.08 [32]
No sexual partners: MSM/PWID 0.08 [46, 47]
No sexual partners: PWID 1.6 [47, 48]
No sexual partners: heterosexual 0.9 [32, 49–51]
Condom use probability: MSM 0.3 [34, 36, 46]
Condom use probability: MSM/PWID 0.3
Condom use probability: PWID 0.3 [35, 46]
Condom use probability: heterosexual 0.3 [51]
Probability of transmission: CD4: >500 0.025 [3, 37, 52–56]
Probability of transmission: CD4: 350–499 0.025
Probability of transmission: CD4: 200–349 0.035
Probability of transmission: CD4: <200 0.065
Decreased number of sexual partners due to diagnosis 0.5 [44]
Reduced probability of transmission on ART 0.96 [5]
Condom effectiveness 0.9 [45]
Costs (2015$CDN)
ART costsc: PWID Time dependentb [73]
 CD4: >500 435 (1996); 1276 (2010)
 CD4: 350–499 464 (1996); 1287 (2010)
 CD4: 200–349 483 (1996); 1287 (2010)
 CD4: <200 478 (1996); 1294 (2010)
ART costsc: non-PWID Time dependentb [73]
 CD4: >500 494 (1996); 1295 (2010)
 CD4: 350–499 523 (1996); 1306 (2010)
 CD4: 200–349 542 (1996); 1305 (2010)
 CD4: <200 537 (1996); 1313 (2010)
Non-ART medical costsd: PWID Time dependentb [74]
 CD4: >500 788 (1996); 745 (2010)
 CD4: 350–499 825 (1996); 784 (2010)
 CD4: 200–349 883 (1996); 1022 (2010)
 CD4: <200 1896 (1996); 1992 (2010)
Non-ART medical costsd: non-PWID Time dependentb [74]
 CD4: >500 317 (1996); 309 (2010)
 CD4: 350–499 362 (1996); 330 (2010)
 CD4: 200–349 471 (1996); 471 (2010)
 CD4: <200 1098 (1996); 763 (2010)
HIV enzyme-linked immunosorbent assay antibody test 13 [75]
Confirmatory Western blot test 21 [75]
Medical care costsd: HIV-negative, MSM 205 [76]
Medical care costsd: HIV-negative, PWID 518 [73, 76]
Medical care costsd: HIV-negative, heterosexual 217 [76]
Intervention costse Appendix
 Hospital-based care testing 32081 (IMP); 12750 (SUS)
 Emergency department testing 42798 (IMP); 9892 (SUS)
 Outpatient clinic testing 49215 (IMP); 14785 (SUS)
 ART initiation 66922 (IMP); 32271 (SUS)
 ART retention 230734 (IMP); 111263 (SUS)
Annual discount rate 0.03
Quality-adjusted life years
Susceptible 1.00 [77]
Infected: CD4: ≥500 0.91 [78–81]
Infected: CD4: 350–499 0.79 [78–81]
Infected: CD4: 200–349 0.79 [78–81]
Infected: CD4: <200 0.72 [78–81]
Diagnosed: CD4: ≥500 0.87 [78–81]
Diagnosed: CD4: 350–499 0.72 [78–81]
Diagnosed: CD4: 200–349 0.72 [78–81]
Diagnosed: CD4: <200 0.72 [78–81]
On ART: CD4>500 0.87 [78–81]
On ART: CD4: 350–499 0.83 [78–81]
On ART: CD4: 200–349 0.83 [78–81]
On ART: CD4: <200 0.82 [78–81]
PWID multiplier 0.90 [27, 82]

Abbreviations: ART, highly active antiretroviral treatment; CDN, Canadian dollars; HIV, human immunodeficiency virus; IMP, implementation phase; MSM, men who have sex with men; PWID, people who inject drugs; SUS, sustainment phase.

a

“Initial” values refer to 1996 values, the start of the model calibration period (1996–2010).

b

Figures presented for time-dependent parameters are 1996 and 2010 values.

c

Includes ART medication costs and associated pharmacy dispensation costs.

d

Includes non-ART medication costs and associated pharmacy dispensation costs, costs of physician billings for outpatient care, and hospitalization cost.

e

Intervention costs were differentiated between the implementation phase and the sustainment phase, with the latter excluding fixed costs of initiating the interventions.