Second-trimester exposure to the 1957 A2 influenza pandemic is a controversial risk factor for schizophrenia.
Two earlier studies of the Dutch psychiatric registry failed to find an increased risk for exposed subjects, but diagnostic misclassification within the spectrum of non-affective psychoses has not yet been ruled out as an explanation for the negative findings.
Using an enlarged data-set we examined not only whether second-trimester exposure to the epidemic is associated with an increased risk of schizophrenia (ICD : 295), but also whether it is associated with an increased risk of paranoid states (ICD : 297) or other non-organic psychoses (ICD : 298).
In this retrospective cohort study the risks of the above-mentioned disorders were compared for those exposed and unexposed to A2 influenza during the second trimester of fetal life.
The risks for the exposed subjects were not significantly higher than the risks for the unexposed.
The power of the study to detect a significant increase in the risk of schizophrenia was sufficient.
If the relative risk of a lifetime hospitalization for schizophrenia for second-trimester exposed subjects (born January-April 1958) is assumed to be 1.3, the power of the study would be 0.97 (alpha=0.05 ; one-tailed testing).
If the relative risk for subjects born five months after the peak of the epidemic (mid-February to mid-March 1958) is assumed to be 1. (...)
Mots-clés Pascal : Schizophrénie, Facteur risque, Antécédent, Exposition, Prénatal, Influenzavirus A, Orthomyxoviridae, Virus, Pays Bas, Europe, Epidémiologie, Forme clinique, Etude longitudinale, Santé mentale, Homme, Psychose
Mots-clés Pascal anglais : Schizophrenia, Risk factor, Antecedent, Exposure, Prenatal, Influenzavirus A, Orthomyxoviridae, Virus, Netherlands, Europe, Epidemiology, Clinical form, Follow up study, Mental health, Human, Psychosis
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0444465
Code Inist : 002B18C06A. Création : 22/03/2000.