Table 1

Model input parameters: probabilities, utilities and costs

ParameterBase case valueLower limitUpper limitDistributionSourceIRIS trial base value*
Probabilities
 Proportion of women experiencing abuse0.170.1470.194Beta 17 0.17
 Starting distribution for women who are abused
  Abused and identified, seeing advocate educator0.003†00.0066Uniform
  Abused and identified, not seeing advocate educator0.033†00.0660Uniform
  Abused but not identified0.964†UniformComplement
 Transition probabilities
  Not abused to abused but not identified0.0037†0.00040.0106Dirichlet0.0075
  Not abused to dead0.00551†0.00100.0136Dirichlet 13 15 0.0058
  Stay in Not abused0.9908†--DirichletComplement0.9867
  Abused but not identified to not abused (control)0.0500†0.04500.0553Dirichlet0.025
  Abused but not identified to abused and identified, not seeing advocate educator (control)0.0027†0.00160.0040DirichletIRIS-programme local sites0.0094
  Abused but not identified to abused and identified, seeing advocate educator (control)0.0005†0.00010.0011DirichletIRIS-programme local sites0.0016
  Abused but not identified to dead (control)0.00554†0.00390.0074Dirichlet 13 15 0.0059
  Stay in abused but not identified (control)0.9444†--DirichletComplement0.9581
  Abused but not identified to not abused (intervention)0.0500†0.04500.0553Dirichlet0.025
  Abused but not identified to abused and identified, not seeing advocate educator (intervention)0.0109†0.00860.0135DirichletIRIS-programme local sites0.0207
  Abused but not identified to abused and identified, seeing advocate educator (intervention)0.0056†0.00400.0076DirichletIRIS-programme local sites0.0101
  Abused but not identified to dead (intervention)0.00554†0.00390.0074Dirichlet 6 0.0059
  Stay in abused but not identified (intervention)0.9419†--DirichletComplement0.9383
  Abused and identified, seeing advocate educator to not abused0.1408†0.07070.2301Dirichlet 18 0.0888
  Abused and identified, seeing advocate educator to dead0.00554†0.00000.0309Dirichlet 13 15 0.0059
  Stay in abused and identified, seeing advocate educator0.8536†--DirichletComplement0.9053
  Abused and identified, not seeing advocate educator to not abused0.0781†0.01360.1912Dirichlet 18 0.0717
  Abused and identified, not seeing advocate educator to dead0.00554†0.00000.0438Dirichlet 13 15 0.0059
  Stay in abused and identified, not seeing advocate educator0.9163†--DirichletComplement0.9223
Utilities
 Not abused0.850.8400.860Beta 23
 Abused but not identified0.630.5030.749Beta 24
 Abused and identified, seeing advocate educator0.650.5180.771Beta 24
 Abused and identified, not seeing advocate educator0.630.5030.749Beta 24
Costs
 Costs of the intervention, per women registered, per 6 months£0.46†£0.01£1.69GammaIRIS-programme local sites£0.55
 Cost of onward referral, once£312†£8£1127GammaIRIS-programme local sites & 11 £298
 Cost of abused but not identified£2043£52£7536Gamma 8 £4721
 Weighted costs abused and identified, seeing advocate educator10.751.25GammaAssumption
 Weighted costs abused and identified, not seeing advocate educator10.91.1GammaAssumption
  • Costs are in 2015/2016 UK£.

  • *Values obtained from Devine et al.11

  • †Value updated from Devine et al.11

  • ‡Internal calculation based on model calibration.