The Stockholm non-affective psychoses study (snaps): the importance of including out-patient data in incidence studies
Article first published online: 30 OCT 2009
© 2009 John Wiley & Sons A/S
Acta Psychiatrica Scandinavica
Volume 121, Issue 5, pages 389–392, May 2010
How to Cite
Jörgensen, L., Ahlbom, A., Allebeck, P. and Dalman, C. (2010), The Stockholm non-affective psychoses study (snaps): the importance of including out-patient data in incidence studies. Acta Psychiatrica Scandinavica, 121: 389–392. doi: 10.1111/j.1600-0447.2009.01500.x
- Issue published online: 13 APR 2010
- Article first published online: 30 OCT 2009
- Accepted for publication October 7, 2009
- non-affective psychoses;
- register study
Jörgensen L, Ahlbom A, Allebeck P, Dalman C. The Stockholm non-affective psychoses study (snaps): the importance of including out-patient data in incidence studies.
Objective: To estimate the incidence rate of schizophrenia and non-affective psychoses from registers, to highlight the importance of including data from out-patient care, and to assess the proportion of persons treated in out-patient care only.
Method: Data from out-patient and in-patient psychiatric care in Stockholm and information from several national registers constitute ‘The Stockholm Non-Affective Psychoses Study’ (SNAPS). Incidence rates based on SNAPS data were calculated and compared to in-patient care incidence rates.
Results: The incidence rate was 72/100 000 for non-affective psychoses (age group 18–44) and 28/100 000 for schizophrenia (age group 18–34) in the SNAPS. This was higher compared to in-patient based incidence rates (42 and 13/100 000 respectively). The proportion of individuals with psychosis treated in out-patient care only was 25%.
Conclusion: There are substantial differences in the incidence rates of non-affective psychoses and schizophrenia depending on the availability of data. Not including out-patient care will underestimate the incidence rates.