other institutions (OR=2.21,95% CI: 1.10, 4.45). This result was not replicated in the present study, when applying the same surrogate measure of exposure (OR=1.1,95% CI:0.6, 2.0). The cases of the 2 studies were, however, diagnosed at different time periods: during 1960-1982 in the former study versus 1990-2007 in the present.