Table 2

Other parameters used in model

EstimateDistributionReference/source
Additional cost parameters and assumptions
Parameters to estimate cost of wheelchair to both household and provider
 % of children needing a wheelchair: severe CZS81.9%Point estimateExpert opinion
 % of children needing a wheelchair: moderate CZS5.0%Point estimateExpert opinion
 % of children needing a wheelchair: no CZS0.1%Point estimateExpert opinion
 Wheelchair cost to the health provider (R$962.5) US$, 2017301.4Point estimate27
 Wheelchair cost (incl. adaptation) to the household (R$4000) US$, 20171252.7Point estimateExpert opinion
 Replacement wheelchair at age (years)3,4,5,6,7 and 10Point estimateExpert opinion
Other costs to the government (education and disability benefit)
 Special creche from age 3 years for CZS (federal payment per pupil R$4420.7) US$, 20171384.5Gamma*45
 Primary education from age 4 (federal payment per pupil: R$4080.7) US$, 20171278.0Gamma*37
 Ratio cost special needs education/cost primary education1.2LognormalExpert opinion
 Disability benefit per year (monthly min. wage: R$937) US$, 20173521.5Point estimate46
Parameters to model costs and outcomes 
General 
 Discount rate costs5%Point estimate35
 Discount rate outcomes5%Point estimate35
 Model length (years)5 and 10Assumption
 Exchange rate Brazilian Real to US$, 20170.31Point estimate31
 Average annual inflation rate Brazil 2008–2017 (mean, SE)6.1%, 1.9%Beta36
Modelling clinical burden 
 Mortality severe CZS year 1 (%, alpha, beta)4.9%, 6, 116BetaEstimated from Rio de Janeiro Cohort
 Mortality severe CZS year 2 (%, alpha, beta)2.6%, 3, 113BetaEstimated from Rio de Janeiro Cohort
 Mortality severe CZS year 3 (%, alpha, beta)0.9%, 1, 112BetaEstimated from Rio de Janeiro Cohort
 Mortality severe CZS year 4 (%, alpha, beta)0.9%, 1, 111BetaAssumed to be the same as year 3
 Mortality severe CZS year 5 (%, alpha, beta)0.9%, 1, 110BetaAssumed to be the same as year 3
 Mortality severe CZS year 6–10 per year (%)0.3%BetaAssumed to be 1/3 of mortality in years 3–5
 Mortality Brazil (moderate CZS and controls) year 1 (%, alpha, beta)1.30%, 13.0, 987.0Beta47
 Mortality Brazil (moderate CZS and controls) year 2 (%, alpha, beta)0.10%, 1.0, 999.0BetaEstimate based on infant and <5-year mortality47
 Mortality Brazil (moderate CZS and controls) year 3 (%, alpha, beta)0.03%, 0.3, 999.7BetaEstimate based on infant and <5-year mortality47
 Mortality Brazil (moderate CZS and controls) year 4 (%, alpha, beta)0.03%, 0.3, 999.7BetaEstimate based on infant and <5-year mortality47
 Mortality Brazil (moderate CZS and controls) year 5 (%, alpha, beta)0.03%, 0.3, 999.7BetaEstimate based on infant and <5-year mortality47
 Mortality Brazil (moderate CZS and controls) year 6–10 per year (%, alpha, beta)0.01%BetaAssumed to be 1/3 of mortality in years 3–5
 Cases of CZS Brazil confirmed3474Point Estimate5
 Cases of CZS Brazil under investigation2659point estimate5
 Cases of CZS Brazil probable743Point estimate5
 Cases of CZS Brazil deceased (fetal death, stillbirth, infant death and child death)505Point estimate5
 Disability weight severe cerebral palsy for severe CZS0.82Lognormal *33
 Disability weight mild/moderate cerebral palsy for mild/moderate CZS0.36Lognormal *33
 Length disability=time horizon of model (years)5 and 10Point estimateDecided by study team

  • Table 2 shows parameters used in the economic burden model, that were not estimated in the costing analysis. This includes parameters to model the cost of a wheelchair as well as other costs to the government, general model parameters such as discount rate and also parameters to model the epidemiological burden of CZS.

  • *Standard error assumed to be 10% of mean.

  • CZS, congenital Zika Syndrome.