Background: There is convincing evidence that DUP is associated with poor outcome. However, despite the knowledge that study refusers have significantly longer DUP than consenters, none of the previous studies assessed an epidemiological sample without informed consent bias.
Methods: 786 first-episode psychosis (FEP) patients were admitted to EPPIC between 1998-2000. Data were collected from medical records of 668 patients meeting inclusion criteria. DUP was categorized into V4, 5-12, 13-52 and >52 weeks. Cox-regression was used to predict remission of positive symptoms (remission) and vocational status (vocation).
Results: Median DUP was 11.8 weeks (0-732); a DUP longer than 3 months (with DUP V4 weeks as reference category) was negatively related to remission (Hazard Ratio (HR)=0.54; CI=0.400.72) and to vocation (HR=0.54; CI=0.390.75) when controlled for gender, age at DUP started, and pre-morbid functioning. Besides DUP, remission was further predicted by better pre-morbid functioning (HR=1.01), older age at start of DUP (HR=1.04), and a lower CGI-S at baseline (HR=0.81). A positive vocation at followup was predicted by better pre-morbid functioning (HR=1.02) and a positive vocation at baseline (HR=1.61).
Conclusions: These findings from a sample without informed consent bias underline the importance of DUP as an independent variable predicting remission and vocation in FEP.