Code of Federal Regulations Title 42. Public Health § 42.81.25 Guidelines for claims including two or more primary cancers

For claims including two or more primary cancers, DOL will use NIOSH–IREP to calculate the estimated probability of causation for each cancer individually. Then DOL will perform the following calculation using the probability of causation estimates produced by NIOSH–IREP:

Equation 1

Calculate:  1–[{1–PC₁} x {1–PC₂} x . . . x {1−PC_n}] = PC_total,

where PC₁ is the probability of causation for one of the primary cancers identified in the claim, PC₂ is the probability of causation for a second primary cancer identified in the claim, and PC_n is the probability of causation for the nth primary cancer identified in the claim. PC_total is the probability that at least one of the primary cancers (cancers 1 through “n”) was caused by the radiation dose estimated for the claim when Equation 1 is evaluated based on the joint distribution of PC₁, . . ., PC_n.  3 DOL will use the probability of causation value calculated for PC_total to adjudicate the claim.

 Evaluating Equation 1 based on the individual upper 99th percentiles of PC₁, . . ., PC_n approximates the upper 99th percentile of PC_total whenever PC₁, . . ., PC_n are highly related, e.g., when a common dose-reconstruction is the only non-negligible source of uncertainty in the individual PC_i's. However, this approximation can overestimate it if other sources of uncertainty contribute independently to the PC₁, . . ., PC_n, whereas treating the joint distribution as fully independent could substantially underestimate the upper 99th percentile of PC_total whenever the individual PC_i's are positively correlated.