Opinion ID: 1919140
Heading Depth: 1
Heading Rank: 27

Heading: Number of Studies

Text: [25] Epidemiological studies assume an important role in determining causation when they are available, and particularly when they are numerous and span a significant period. [150] Courts should normally require more than one epidemiological study showing a positive association to establish general causation, because a study's results must be capable of replication. [151] But courts are understandably reluctant to set a specified minimum number of studies showing a positive association before an expert can reliably base an opinion on themparticularly when there are other, nonepidemiological studies also supporting the expert's opinion. [152] But we do not preclude a trial court from considering as part of its reliability inquiry whether an expert has cherry-picked a couple of supporting studies from an overwhelming contrary body of literature. Here, however, we need not determine whether Frank relied on a sufficient number of epidemiological studies. While BNSF contests Frank's studies on other grounds, it acknowledges that several studies have shown positive associations between multiple myeloma and exposure to diesel exhaust or benzene. [153]