Table 2 Summary of input parameters and assumptions in the Monte Carlo simulation of the SCDS results adjusted for outcome misclassification, selection bias and confounding

Observed exposure: mercury concentration in maternal hair (mg/g)

Mean_x = 6.9, SD_x = 4.5

Myers et al., 2003 (7)

Observed outcome: Score on Boston naming test

Mean_y = 26.5, SD_y = 4.8

Myers et al., 2003 (7)

Observed b₁

N (-0.012, 0.046)

Myers et al., 2003 (7)

Observed b₀

= 26.5 - 6.9 × Observed b₁

Derived using standard linear regression formula (b₀ = -b₁ )

P1: proportion of exposed with a1 (negative) adjustment

U (0.1,0.3)

Hypothetical (no data available)

P2: proportion of exposed with a2 (positive) adjustment

U (0.1,0.3)

a1: relative adjustment in outcome for proportion p1 of subjects

U (0.0,1.95)

Hypothetical (no data available), limits chosen as to allow BNT score vary between 0 and 60

a2: relative adjustment in outcome for proportion p2 of subjects

U (0.0,1.95)

Observed exposure: mercury concentration in cord blood (mg/L)

See above

10,000 vectors (Mean_y, Sd_y, b₀, b₁) adjusted for information bias

Output of Information Bias module

Number of subjects included in the analysis

643

Myers et al. 2003 (7)

Number of eligible subjects

1480

Calculated as 740 × 2 (740 are ~50% of eligible population (7)

Number of subjects excluded from the analysis

837

Calculated as 1480 - 643

Relative difference between mean exposure of subjects not included and mean exposure of included subjects

U (-5%,5%)

Hypothetical (no data available)

Relative difference between mean outcome of subjects not included and mean outcome of included subjects

U (-10%,10%)

Hypothetical (no data available)

Slope multiplier (to get to slope of non-included subjects)

U (0,2)

Hypothetical (no data available)

10,000 vectors (Mean_x, SD_x, Mean_y, SD_y, b₀, b₁) adjusted for information and selection bias

Output of Selection Bias Module

Pearson correlation between confounder (WAIS) and exposure

U (-0.5, 0.5)

Hypothetical (no data available)

Pearson correlation between confounder (WAIS) and outcome

U (0.2, 0.8)

Hypothetical (no data available)