It depends on the size of the window. If schizophrenia shows up between 20-25 years later, then the 1 year effects of the quarantine get distributed over that 5 year window, and are much harder to detect above other fluctuations.
It would show up as people with a particular year of birth having a much lower risk than people born one year earlier or later. Since most research includes collecting date of birth, this should be easy to check.
Yes, I meant exactly a 1 year effect and a random 5 year window and I should have spelled that out. Cancer and many autoimmune diseases take years to notice.
And Jim is right that my example is poor because a prenatal effect pinpoints when the exposure must have occurred. But, actually, I believe that such simple studies don’t find an effect for the normal variation in flu (3% some years, 15% others), except for the 1918 cohort. The studies that find an effect rely on asking the mother if she had flu during pregnancy (which has some post hoc problems).
It depends on the size of the window. If schizophrenia shows up between 20-25 years later, then the 1 year effects of the quarantine get distributed over that 5 year window, and are much harder to detect above other fluctuations.
It would show up as people with a particular year of birth having a much lower risk than people born one year earlier or later. Since most research includes collecting date of birth, this should be easy to check.
Yes, I meant exactly a 1 year effect and a random 5 year window and I should have spelled that out. Cancer and many autoimmune diseases take years to notice.
And Jim is right that my example is poor because a prenatal effect pinpoints when the exposure must have occurred. But, actually, I believe that such simple studies don’t find an effect for the normal variation in flu (3% some years, 15% others), except for the 1918 cohort. The studies that find an effect rely on asking the mother if she had flu during pregnancy (which has some post hoc problems).