Table 1

 Input parameters for model (parameters that were estimated by expert panel are in italics)

ParameterValueSourceRange for sensitivity analysis
*Refers to the first two years of disease.
†Disease after two years of continued exposure.
NPV, net present value; YNHH, Yale New Haven Hospital.
Clinical parameters:
Sensitisation rate2.8%/yearPetsonk et al230.7%/year21 to 5.3%/year23
Time to diagnosis
    1. No surveillance2.7 years after onset of symptomsTarlo et al1018 months42 – 5.9 years10
    2. With surveillance1.7 years after onset of symptomsTarlo et al106 months43 – 2.7 years
Disease progression
    1. Exposed 2 years Expert panel 1–10 years
    2. Removed51% remain symptomaticExtrapolated from Pisati et al70–50% at 48 months recovered8
Chance of removal
    1. If patients diagnosed71% of workers removed at 6 monthsRoss and McDonald1215% at 11 years4499% removed at 6 months
    2. Undiagnosed patients24% change job within 1 yearBlanc et al41 0 to same rate as 1
Chance of recovery, if removed
    1. More reversible*At 5 years, 28% of removed patients recoveredPisati et al750% at 4 years8 – 18% at 10 years45
    2. Less reversible†14% at 5 yearsExtrapolated from Pisati et al7
Likelihood of disability
    1. Removed30% disabled at 4 yearsRoss and McDonald120–69% at 4.1 years45
    2. Still exposed 60% disabled at 4 years Expert panel
Cost parameters:
Lost productivity
    1. Employer perspective$0NoneNone
    2. Societal perspectiveNPV of 28% income loss × 10 years on $50,000/yearMoscato et al28 and industry profile2728%–56%28
Diagnosis costs
    1. Screening cost$103.88Charges YNHH, with cost:charge ratio of 0.4550% to 200%
    2. Confirmation$453.53
Medical/absenteeism costs
    1. Symptomatic state$42.62/monthBirnbaum et al,29 and calculations from model50–200%
    2. Chronic state$85.24/monthAs for 1As for 1
    3. Disabled state$1513.60/monthAs for 1As for 1
Discount rate3%US Panel160–7%16