Skip to main content

Does duration of untreated psychosis bias study samples of first-episode psychosis?

Buy Article:

$43.00 plus tax (Refund Policy)

Friis S, Melle I, Larsen TK, Haahr U, Johannessen JO, Simonsen E, Opjordsmoen S, Vaglum P, McGlashan TH. Does duration of untreated psychosis bias study samples of first episode psychosis?

Acta Psychiatr Scand 2004: 110: 286–291. © Blackwell Munksgaard 2004. Objective: 

While findings are contradictory, many studies report that long Duration of Untreated Psychosis (DUP) correlates with poorer outcome in first episode psychosis. In an outcome study of first-episode psychosis, we compared the patients who refused to participate in a follow-along with those who consented to estimate the importance of this factor in sample recruitment bias. Our questions were: (i) What is the percentage of refusers? (ii) Are there systematic differences between refusers and consenters on DUP and/or other admission variables? (iii) What is the risk of refusal for different values of DUP? Method: 

In an unselected group of consecutively admitted patients we compared follow-along refusers and consenters on the following admission variables: sex, age, diagnostic group, substance abuse, being in-patient, coming from an early detection site and DUP. We conducted a logistic regression analysis with refusal as the outcome variable. Results: 

Ninety-three of 397 patients (23%) were refusers. In univariate analyses the only significant difference was found for DUP. The median DUP for consenters was 10 weeks and for refusers 32 weeks. DUP remained significant when all independent variables were controlled for. Conclusion: 

DUP was significantly related to risk for refusal. For tests of the impact of DUP on outcome, this may introduce a type II error bias.
No References
No Citations
No Supplementary Data
No Data/Media
No Metrics

Keywords: bias; duration of untreated psychosis; first episode psychosis; outcome; sampling; schizophrenia

Document Type: Research Article

Publication date: 2004-10-01

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more