You are viewing the site in preview mode

Skip to main content

Advertisement

Table 1 Transition probabilities

From: Health economic evaluation of vaccination strategies for the prevention of herpes zoster and postherpetic neuralgia in Germany

State (From state → To state) Variable Formula
Death   
  Death → Death λi =1
  Any state → Death αi = p i Background Mortality
  Status quo [no vaccination]  
Healthy   
  Healthy → Herpes zoster βi = 1 - α i 1 - e - I i Healthy HZ
  Healthy → Healthy γi = 1 - α i - β i
Herpes zoster   
  Herpes Zoster → Death δi = 1 - α i 1 - e - I i HZ Death
  Herpes Zoster → PHN ϵi = 1 - α i 1 - e - I i HZ PHN
  Herpes Zoster → Healthy after disease ζi =  1 - α i - δ i - ϵi
PHN   
  PHN → PHN ηi = χ 1 , D PHN σ 1 - α i
  PHN → Healthy after disease θi = 1 - α i - ηi
Healthy after disease   
  Healthy after disease → Healthy after disease κi = χ 1 , D Rec σ 1 - α i + χ D Rec , σ γ i
  Healthy after disease → Herpes zoster ιi = 1 - α i - κ i
  Vaccine-Scenario [adapted transition probability due to vaccine efficacy (VE)]  
Healthy   
  Healthy → Herpes zoster βi V = β i 1 - VE i HZ
  VEi HZ = χ j , μ i IVE j HZ + χ μ , i IVE j HZ e - π * i - μ
  Healthy → Healthy γi V = 1 - α i - β i V
HZ   
  Herpes zoster → PHN ϵi V = ϵ i 1 - VE i PHN
  VEi PHN = χ j , μ i IVE j PHN + χ μ , i IVE j PHN e - π * i - μ
Healthy after disease   
  Healthy after Disease → Healthy after disease κi V = χ 1 , D Rec σ 1 - α i + χ D Rec , σ γ i V
  Healthy after Disease → Herpes zoster ιi V = 1 - α i - κ i V
  1. p = probability of death with respect to cycle-length; i = age = Start_Age +(n_cycles); χ A(x) = Indicator function; σ = Tunnel (counter for cycles staying in state); DPHN = Duration of PHN; DRec = Duration until Recurrence is possible; v = indicating the vaccine scenario; j = Age at Vaccination; μ = Age at Vaccination plus n years; I = Age-group specific Incidencefrom_state→to_state with respect to cycle-length; VEi HZ = Vaccine efficacy protecting against HZ; IVEj HZ = Initial Vaccine efficacy protecting against HZ by age at vaccination; VEi PHN = Vaccine efficacy protecting against PHN by certain age in model; IVEj PHN = Initial Vaccine efficacy protecting against PHN by age at vaccination; π = Waning rate with respect to cycle-length.