A comparison of clinical and research DSM-III-R diagnoses of schizophrenia in a Finnish national birth cohort

Abstract

As a prerequisite to the use of the Finnish National Hospital Discharge Register in psychiatric epidemiological research, we studied the diagnostic reliability of the register in terms of the psychiatric morbidity experienced by a national birth cohort. We investigated all entries to the register for a sample based upon the Northern Finland 1966 birth cohort at the age of 16 years (n = 11017). Until the end of 1993 (age 27 years), a total of 563 subjects had a register diagnosis indicating a psychiatric illness, 37 of them being schizophrenia. When operational criteria (DSM-III-R) were applied to clinical information in the available original hospital records for cases of psychosis, personality disorder and substance abuse (n = 249), 71 fulfilled criteria for schizophrenia, including all of the 37 cases in the register and an additional 34 (48% false-negatives), most frequently diagnosed in the register as schizophreniform or other psychosis. Despite the official use of DSM-III-R nomenclature, it appears that the clinical concept of schizophrenia in Finland, manifest within the register, remains very restrictive. The application of operational criteria is a necessary prerequisite for scientific research on schizophrenia.

Birth order and risk for schizophrenia: a 31‐year follow‐up of the Northern Finland 1966 Birth Cohort

“…Our study population consisted of all hospitaltreated schizophrenia cases except two patients, who were treated solely as out-patients (16). In Finland the vast majority of schizophrenia and other psychoses are treated in some phase of life in a mental hospital, and are thereby included in the FHDR.…”

“…Data on biological, socioeconomic and health conditions, living habits and family characteristics of cohort members were collected prospectively from pregnancy up to the age of 31 years. Up to age 16, 284 had died and 757 emigrated, leaving 11 017 individuals living in Finland at age of 16 years for the present study (15,16).…”

Hospital-treated mental and behavioral disorders and risk of Alzheimer's disease: A nationwide nested case-control study

“…On the other hand, previous validation studies have shown that the Hospital Discharge Register is able to capture nearly all persons with schizophrenia, schizotypal and delusional disorders. (44,45) Although all AD diagnoses were clinically verified according to a standard protocol, one limitation is that the diagnoses were probable AD rather than definite AD. However, the validity was improved by the practice that diagnoses were assessed by two independent specialists in clinical practice, and further evaluation was done in the SII according to the predefined criteria.…”

The persistence of developmental markers in childhood and adolescence and risk for schizophrenic psychoses in adult life. A 34-year follow-up of the Northern Finland 1966 birth cohort

“…Detailed description and additional information regarding the study variables and methods is available from previous reports (Isohanni et al, 2001 (Rantakallio, 1969;Isohanni et al, 1997).…”

“…ICD-8 290-309, DSM-III-R diagnoses 290-316, and ICD-10 F 00-F69, F99) were identified. All case records were scrutinized and diagnoses were validated for the DSM-III-R criteria (Isohanni et al, 1997;Moilanen et al, 2003). Interrater reliability was good with kappa values from 0.6 to 0.9.…”