title: Diagnostic stability among chronic patients with functional psychoses: an epidemiological and clinical study.
abstract: BACKGROUND
  Diagnostic stability and illness course of chronic non-organic psychoses are complex phenomena and only few risk factors or predictors are known that can be used reliably. This study investigates the diagnostic stability during the entire course of illness in patients with non-organic psychoses and attempts to identify non-psychopathological risk factors or predictors.
  
  
  METHODS
  100 patients with functional psychosis were initially characterised using the Operational Criteria Checklist for Psychotic Illness and Affective Illness (OPCRIT), medical records and health registers. To study the stability of diagnoses (i.e. shifts per time), we used registry data to define four measures of diagnostic variation that were subsequently examined in relation to four possible measures of time (i.e. observation periods or hospitalisation events). Afterwards, we identified putative co-variables and predictors of the best measures of diagnostic stability.
  
  
  RESULTS
  All four measures of diagnostic variation are very strongly associated with numbers-of-hospitalisations and less so with duration-of-illness, duration-of-hospitalisation and with year-of-first-admission. The four measures of diagnostic variation corrected for numbers-of-hospitalisations were therefore used to study the diagnostic stability. Conventional predictors of illness course - e.g. age-of-onset and premorbid-functioning - are not significantly associated with stability. Only somatic-comorbidity is significantly associated with two measures of stability, while family-history-of-psychiatric-illness and global-assessment-of-functioning (GAF) scale score show a trend. However, the traditional variables age-of-first-admission, civil-status, first-diagnosis-being-schizophrenia and somatic-comorbidity are able to explain two-fifth of the variation in numbers-of-hospitalisations.
  
  
  CONCLUSIONS
  Diagnostic stability is closely linked with the contact between patient and the healthcare system. This could very likely be due to fluctuation of disease manifestation over time or presence of co-morbid psychiatric illness in combination with rigid diagnostic criteria that are unable to capture the multiple psychopathologies of the functional psychoses that results in differential diagnoses and therefore diagnostic instability. Not surprisingly, somatic-comorbidity was found to be a predictor of diagnostic variation thereby being a non-psychiatric confounder.
authors: Research Institute of Biological Psychiatry, Sct. Hans Hospital, DK-4000 Roskilde, Denmark. kdjakobsen@gmail.com
authors: Klaus D
authors: KD
authors: Jakobsen
authors: Thomas
authors: T
authors: Hansen
authors: Thomas
authors: T
authors: Werge
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002908:Chronic Disease; D015331:Cohort Studies; D015897:Comorbidity; D003937:Diagnosis, Differential; D005260:Female; D006296:Health Services / Q000706:statistics & numerical data; D006304:Health Status; D006801:Humans; D008297:Male; D011379:Prognosis; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D012307:Risk Factors
references: Pharmacogenomics J. 2006 Mar-Apr;6(2):120-5
references: 16402085
references: Psychiatry. 2006 Spring;69(1):47-68
references: 16704332
references: Arch Gen Psychiatry. 1972 Jan;26(1):57-63
references: 5009428
references: Arch Gen Psychiatry. 1991 Aug;48(8):764-70
references: 1883262
references: Acta Psychiatr Scand Suppl. 1993;370:27-32
references: 8452052
references: Br J Psychiatry. 2007 Mar;190:210-6
references: 17329740
references: World Psychiatry. 2006 Oct;5(3):168-71
references: 17139352
references: Nord J Psychiatry. 2005;59(3):209-12
references: 16195122
references: Psychol Med. 1996 Jul;26(4):775-83
references: 8817712
references: Cochrane Database Syst Rev. 2000;(2):CD000384
references: 10796354
references: Psychopathology. 2006;39(6):269-76
references: 16960465
references: Br J Psychiatry. 1998 Dec;173:494-500
references: 9926078
references: Nord J Psychiatry. 2005;59(6):457-64
references: 16316898
references: Soc Psychiatry Psychiatr Epidemiol. 2003 Jun;38(6):305-10
references: 12799780