High incidence of admissions for schizophrenia in Surinam patients in The Netherlands not caused by preferential immigration of (pre)schizophrenic patients

OBJECTIVE: To answer the question whether positive selection of (pre)schizophrenic Surinams in Surinam before emigration to the Netherlands can explain the high admission rates for schizophrenia of Surinams in the Netherlands. DESIGN: Retrospective research. SETTING: 's Lands Psychiatrisch Ziekenhuis (National Psychiatric Hospital) Paramaribo, Surinam (LPZ). METHOD: The Netherlands Central Bureau of Statistics in Voorburg and the Central Registry Office in Paramaribo provided data on emigration to the Netherlands of the Surinam population and on remigration. Files of (pre)schizophrenic patients were selected from the records of LPZ. Subsequently, these patients were traced and their pattern of migration was studied. Using the chi 2 test the significance of observed differences was assessed. RESULTS: Surinam (pre)schizophrenic patients did not emigrate more frequently to the Netherlands (6.3%) compared with the Surinam population in general (9.6%) and they remigrated more frequently to Surinam than the Surinams in general. CONCLUSION: The positive selection hypothesis must be rejected.