Accuracy of register-based schizophrenia diagnoses in a genetic study

Abstract

In order to assess the accuracy of schizophrenia diagnoses for genetic studies, we identified all schizophrenia patients (n = 492) in an isolated community with a diagnosis of schizophrenia in the Finnish Hospital Discharge Register (HDR) between 1969-1991. For the accuracy study we identified a sample of 73 patients from registers with Diagnostic and Statistical Manual (DSM)-III-R for schizophrenia (codes 295.10, 295.30, 295.60, 295.90) (n = 62) or "schizophrenia spectrum" diagnoses (295.40, 295.70, 297.10, 301.20, 301.22) (n = 11). When the operational criteria (DSM-III-R) were applied by two senior researchers using information from the original mental hospital records, 93% (68/73) of the cases fulfilled criteria for schizophrenia or schizophrenia spectrum. The results demonstrate that the schizophrenia diagnoses of the registers are accurate when a broad concept of schizophrenia is applied. When using operational DSM-III-R schizophrenia criteria, eight false positive cases were found among the 62 mental hospital schizophrenia diagnoses. Consequently, there may be a need to reassess schizophrenia diagnoses depending on the purpose of the study. We also found good agreement between DSM-III-R (kappa 0.93) and operational criteria (OPCRIT) diagnostic system (kappa 0.89) diagnoses, made by one researcher, compared with operational diagnoses. This indicates the possibility for the reliable use of one of these methods alone for diagnostic reassessment. The information in the HDR on primary diagnoses and on the dates of admission and discharge was accurately transferred from the hospital records.

School Performance in Finnish Children and Later Development of Schizophrenia

“…18 The diagnostic validity of the FHDR has been examined against DSM-III-R criteria and has been found to have excellent (92%-100%) specificity for diagnoses of schizophrenia. [19][20][21] We identified 928 individuals from the registers who had received a "295" diagnosis and who were born in Helsinki between 1951 and 1960. Child health cards were located for 486 of these individuals (52%) in the city archives, indicating that they had attended school in Helsinki; the remainder had attended school elsewhere.…”

Intrahepatic cholestasis of pregnancy as an indicator of liver and biliary diseases: A population-based study

“…[38][39][40][41][42] The validity of the Finnish Hospital Discharge Register has been evaluated in several studies. [21][22][23][24] Virtually all inpatient hospital care periods in Finland are recorded in the register because the reporting is compulsory. The accuracy of most variables utilized in this study (personal and hospital ID numbers, age, sex, and dates of admission and discharge) is at least 95%.…”

“…Several studies have concluded that the register has reasonably good validity for epidemiological research. [21][22][23][24] During the years 1972-2000, three versions of the International Classification of Diseases (ICD-8, -9, and -10) were used in Finland. The diagnosis related codes used in the identification of the study population were as follows: during ICD-8 (1972ICD-8 ( -1986 63,900 (hepatosis gravidarum, n ϭ 3,831)/63,901 (icterus gravis gravidarum, n ϭ 132)/63,909 (necrosis acuta et subacuta hepatis gravidarum, n ϭ 162); during ICD-9 (1987-1995) 6467A (hepatosis gravidarum, n ϭ 4,226)/6,467X (hepatopathia alia gravidarum, n ϭ 72); and during ICD-10 (1996-2000) O26.6 (intrahepatic cholestasis of gravidarum, n ϭ 2,081).…”

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.…”