title: Do psychiatric registries include all persons with schizophrenia in the general population? A population-based longitudinal study.
abstract: BACKGROUND
  Psychiatric hospitalization registries are utilized to investigate the incidence and prevalence of schizophrenia for both research and administrative purposes. The assumption behind this is that most individuals with schizophrenia will be hospitalized at least once in their life-time.
  
  
  METHODS
  In an epidemiological survey conducted in the 1980s, a population-based sample (n = 4914) of Israel-born individuals then aged 25-34 were screened in the community, and 29 (0.6%) were subsequently diagnosed by psychiatrists using SADS/RDC criteria. Twenty four years later we linked data from the epidemiological survey with the Israeli National Psychiatric Hospitalization Registry.
  
  
  RESULTS
  Twenty seven of the 29 individuals (93%) diagnosed with schizophrenia in the survey were identified in the hospitalization registry with the same diagnosis. Fifty-two (1.0%) participants not diagnosed during the survey with schizophrenia were identified in the psychiatric hospitalization registry 24 years later with schizophrenia. The majority of them were diagnosed with other psychiatric disorders in the survey. If all diagnoses of schizophrenia are accepted at face value, the lifetime prevalence rate would be 1.8% for this cohort.
  
  
  CONCLUSIONS
  The overwhelming majority of individuals diagnosed with schizophrenia at ages 25-34 in an epidemiological survey were present in the Psychiatric Hospitalization Registry. However, the assessment of life-time rates of schizophrenia at these ages is problematic because some future cases are asymptomatic, others have premorbid non-psychotic disorders, while in others it is difficult to differentiate between affective disorders and schizophrenia. Availability of psychiatric services and hospitalization policy must be considered when generalizing these findings to other countries.
authors.affiliation: Department of Psychiatry, Sheba Medical Center, Tel-Hashomer, Israel. mweiser@netvision.net.il
authors.forename: Mark
authors.initials: M
authors.lastname: Weiser
authors.forename: Nomi
authors.initials: N
authors.lastname: Werbeloff
authors.forename: Bruce P
authors.initials: BP
authors.lastname: Dohrenwend
authors.forename: Itzhak
authors.initials: I
authors.lastname: Levav
authors.forename: Rinat
authors.initials: R
authors.lastname: Yoffe
authors.forename: Michael
authors.initials: M
authors.lastname: Davidson
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D018672:Community Health Planning; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D007557:Israel / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D012042:Registries / Q000706:statistics & numerical data*; D012559:Schizophrenia / Q000453:epidemiology*