Diagnostic agreement of schizophrenia spectrum disorders among chronic patients with functional psychoses

BACKGROUND: To investigate whether diagnostic agreement across different diagnostic systems improves in a sample of chronic patients suffering from functional psychosis compared to first-admitted patients. SAMPLING AND METHODS: Among 353 patients with a history of functional psychosis, a subset of 100 individuals (35 women and 65 men) were randomly sampled and assessed using the Operational Criteria Checklist for Psychotic Illness and Affective Illness (OPCRIT). Based on the OPCRIT diagnoses the subjects suffering from schizophrenia and schizophrenia spectrum disorders according to seven diagnostic systems were identified. Diagnostic agreement was assessed using unweighted kappa-statistics and pairwise concordance rates (CR). RESULTS: High diagnostic agreement of schizophrenia was observed across the ICD-10 and DSM systems (CR >0.70, kappa >0.70), which all had a significantly lower concordance to the St. Louis Criteria (SLC), research diagnostic criteria and Schneider's first rank symptoms (FRS) (0.32< CR <0.66; -0.10< kappa <0.51). Agreement on schizophrenia across all systems was observed for one fourth of the subjects. Elimination of the diagnostic impact of 'co-occurrence of psychotic and affective symptoms' excluded FRS standalone individuals from the sample, increased overall homogeneity and resulted in a dichotomized sample according to SLC (46 positive vs. 47 negative). SLC status could be predicted in 78% of cases by four items relating to family history and psychosocial function previous to the onset of illness. Similarly high pairwise CR were observed for schizophrenia spectrum disorders across all diagnostic systems. CONCLUSIONS: This study demonstrates that diagnostic agreement is higher among chronic patients than that observed in subjects with a recent onset of psychosis, although considerable discordance is also observed in this chronic sample. However, the discordance among chronic patients with functional psychosis largely derives from the different emphasis that diagnostic systems place on co-occurrence of psychotic and affective symptoms. This may have serious epistemological consequences, thus underlining the conventional nature of the present schizophrenia diagnoses and the need for biologically founded diagnostic criteria.     

Evaluation of diagnostic procedures in Swedish patients with schizophrenia and related psychoses

We aimed to estimate the value of structured interviews, medical records and Swedish register diagnoses for assessing lifetime diagnosis of patients with schizophrenia. Psychiatric records and diagnostic interviews of 143 Swedish patients diagnosed by their treating physician with schizophrenia and related disorders were scrutinized. Based on record analysis only, or a combined record and interview analysis, DSM-IV diagnoses were obtained by the OPCRIT algorithm. Independent of the OPCRIT algorithm, a standard research DSM-IV diagnosis, based on both record and interview analysis, was given by the research psychiatrist. Concordance rates for the different psychosis diagnoses were calculated. DSM-IV diagnoses based on records only, showed a good to excellent agreement with diagnoses based on records and interviews. Swedish register diagnoses displayed generally poor agreement with the research diagnoses. Nevertheless, 94% of subjects sometimes registered with a diagnosis of schizophrenic psychoses (i.e. schizophrenia, schizoaffective psychosis or schizophreniform disorder) displayed a standard research DSM-IV diagnosis of these disorders. For patients in long-term treatment for schizophrenia in Sweden, psychiatric record reviews should be optimal, cost effective and sufficient for assessment of lifetime research diagnoses of schizophrenia. For these patients a research interview adds little new information. The results further indicate that a Swedish register diagnosis of schizophrenic psychoses has a high positive predictive power to a standard research DSM-IV diagnosis of the disorders. It is concluded that for future Swedish large-scale genetic studies focusing on a broad definition of schizophrenia, it would be sufficient to rely on the Swedish register diagnoses of schizophrenic psychosis.     

Evaluation of diagnostic procedures in Swedish patients with schizophrenia and related psychoses

We aimed to estimate the value of structured interviews, medical records and Swedish register diagnoses for assessing lifetime diagnosis of patients with schizophrenia. Psychiatric records and diagnostic interviews of 143 Swedish patients diagnosed by their treating physician with schizophrenia and related disorders were scrutinized. Based on record analysis only, or a combined record and interview analysis, DSM-IV diagnoses were obtained by the OPCRIT algorithm. Independent of the OPCRIT algorithm, a standard research DSM-IV diagnosis, based on both record and interview analysis, was given by the research psychiatrist. Concordance rates for the different psychosis diagnoses were calculated. DSM-IV diagnoses based on records only, showed a good to excellent agreement with diagnoses based on records and interviews. Swedish register diagnoses displayed generally poor agreement with the research diagnoses. Nevertheless, 94% of subjects sometimes registered with a diagnosis of schizophrenic psychoses (i.e. schizophrenia, schizoaffective psychosis or schizophreniform disorder) displayed a standard research DSM-IV diagnosis of these disorders. For patients in long-term treatment for schizophrenia in Sweden, psychiatric record reviews should be optimal, cost effective and sufficient for assessment of lifetime research diagnoses of schizophrenia. For these patients a research interview adds little new information. The results further indicate that a Swedish register diagnosis of schizophrenic psychoses has a high positive predictive power to a standard research DSM-IV diagnosis of the disorders. It is concluded that for future Swedish large-scale genetic studies focusing on a broad definition of schizophrenia, it would be sufficient to rely on the Swedish register diagnoses of schizophrenic psychosis.     

Characteristics of very poor outcome schizophrenia

The authors compared 21 "Kraepelinian" schizophrenic patients who had been ill and dependent on others for the past 5 years with 76 chronic schizophrenic patients in remission or with exacerbations requiring hospitalization. The Kraepelinian patients met the criteria for schizophrenia by more diagnostic systems than the exacerbated patients, were less responsive to haloperidol, had more severe negative symptoms, and had similarly severe positive symptoms. They had cerebral ventricles that were more asymmetrical and a greater family history of schizophrenia spectrum disorders than the other chronic patients. These data suggest that patients with 5 years of illness and complete dependency on others may represent a subgroup of schizophrenia.     

Research in schizophrenia: necessity to include patients of multiple diagnostic systems]

The discrepancies of studies on symptomatology and treatment of schizophrenia could be related to the selection of different patients diagnosed by one diagnostic system, different from a study to another. Therefore, we tested whether 14 diagnostic systems could include 51 patients differently as regard to the intensity of positive, negative or depressive symptomatology and to the phase of illness. The distribution of the patients in different sets of diagnosis has been carried out by a computer program and the symptomatology has been evaluated with PANSS and MADRS. Some diagnostic criteria like DSMIII-R, Langfeldt, Taylor, ICD 9 include negative and depressive patients preferentially. Others systems like Berner, Catego, ICD 9, New-Haven, Schneider, include more patients with acute than residual symptoms. These results show the importance of the choice of one or more diagnostic criteria depending on the aim of the study.     

Reliability and concordance in the subtyping of schizophrenia

The authors examined the reliability, frequency, concordance, and demographic characteristics of subtypes of schizophrenia in patients from the Iowa 500 study as defined by four major diagnostic systems: DSM-III, Research Diagnostic Criteria (RDC), ICD-9, and the Tsuang-Winokur criteria. Reliability was higher in diagnostic systems with operationalized than in those with unoperationalized criteria and consistently higher for the paranoid subtype. The frequency of individual subtypes varied widely for the different systems. Concordance for subtype diagnoses between systems ranged from quite high to quite low. Demographic characteristics of the individual subtypes were similar according to all systems.     

The reassessment of chronic patients previously diagnosed as schizophrenic

Sixty-one outpatients with clinical diagnoses of schizophrenia or schizoaffective disorder were systematically reevaluated with a structured historical diagnostic interview, the Schedule for Affective Disorders and Schizophrenia-Lifetime Version, and with a review of their charts. Research diagnoses were then constructed by applying Research Diagnostic Criteria (RDC) to the interview data and seven diagnostic systems to the chart data. Of the 61 patients, 43 (70.5%) were again recognized to be schizophrenic by the RDC applied to the interview data and 39 (63.5%) met chart criteria. Fifty-one patients (83.6%) were rediagnosed as schizophrenic by at least one of these approaches (excluding the NHSI chart criteria). There was, however, great variation in rediagnostic assignment because of variations in the diagnostic criteria and chart data. Many of the patients who did not meet criteria for schizophrenia met criteria for affective disorder. Patients were assigned to one of four categories according to whether interview or chart rediagnosis was positive or negative for schizophrenia. This categorization was used to search for factors that might account for patients who did not receive a rediagnosis of schizophrenia.     

Epidemiology of cycloid psychosis

Summary The objective of the present study on cycloid psychosis was to describe the incidence and risk in a defined population sample. We therefore re-evaluated specific diagnostic groups in the 1947 cohort of the Lundby Study. Three female cases were identified as cycloid psychosis according to the diagnostic criteria of Leonhard, Perris and Brockington. No men were found. The incidence rate (per 100 observation years) was found to be 0.016% for women. The cumulative probability i.e. risk, up to 60 years of age was calculated to be 0.7%. Incidence rate and risk for cycloid psychosis in women was thus about half of the corresponding values for schizophrenia as described for the same population in a parallel study. We conclude that cases of cycloid psychosis constitute a substantial proportion of female psychotic patients.The present study was financed by the following grants: Nos. 4803, 06881 from The Swedish Medical Research Council, No. 83/64:1 from The Swedish Ministry of Health and Social Affairs, Delegation for Social Research and Pfannenstillska Stiftelsen     

Characterization of patients with schizophrenia and related psychoses: evaluation of different diagnostic procedures

BACKGROUND: We aimed at estimating the value of structured interviews, medical records and clinical diagnoses for assessing lifetime diagnosis of patients with schizophrenia. In addition, the validity of the Operational Criteria Checklist (OPCRIT) system was analysed. SAMPLING AND METHODS: Swedish patients (n = 73), diagnosed with schizophrenia and related disorders by their treating physician, were scrutinized. Independent research diagnoses according to the Diagnostic and Statistical Manual, ed. 3, revised (DSM-III-R) were obtained by (1) a structured interview; (2) the OPCRIT algorithm, based on record analysis only; (3) the OPCRIT algorithm, based on record and interview analysis, or (4) a separate traditional research diagnosis based on both record and interview analysis. In addition, clinical International Classification of Diseases (ICD) diagnoses, given by the treating physician, were obtained from the case notes. Concordance rates for the different psychosis diagnoses were calculated. RESULTS: Diagnoses based on interviews only showed poor to fair agreement with the other research diagnoses, but patients diagnosed with schizophrenia or schizophrenic psychoses (i.e. schizophrenia, schizophreniform or schizoaffective disorder) at the interview almost always also obtained a corresponding research diagnosis based on record or combined sources. Diagnoses based on records only showed a good to excellent agreement with diagnoses based on records and interviews. Clinical ICD diagnoses generally displayed poor agreement with the research diagnoses, but 94% of patients ever given a clinical ICD diagnosis of schizophrenic psychosis received a corresponding traditional research diagnosis. OPCRIT diagnoses and independently assigned research diagnoses, based on the same information, displayed excellent concordance. CONCLUSIONS: Structured interviews performed with Swedish long-term-treated psychosis patients during non-hospitalization are a poor source for the evaluation of psychosis diagnoses, but a good screening instrument for the detection of DSM-III-R schizophrenia. In the investigated population, medical records are a valuable source for diagnostic assessment of psychoses and may serve as a stand-alone procedure in this patient category. Swedish clinical ICD diagnoses have a high positive predictive power identifying DSM-III-R diagnoses of schizophrenic psychoses, indicating validity of register-based research focusing on these diagnoses. The OPCRIT system is a valid tool for assessing DSM-III-R psychosis diagnoses. It should be emphasized that the present conclusions are based on the investigated Swedish psychosis population and cannot be generalized to populations composed of other patient groups or sampled in other settings, with other traditions regarding the use and availability of medical records.     

The influence of gender on the classification of psychotic disorders--a multidiagnostic approach

A multidiagnostic approach was used prospectively to classify a sample of 176 psychotic patients. An excess of males was found with only one out of 11 systems of schizophrenia, the World Health Organization "flexible" system of schizophrenia, with an excess of females noted in 2 of 5 systems of schizoaffective disorder, the Kasanin schizoaffective system and the Feighner schizoaffective depressed category. Correlation matrices of the diagnostic categories were generated for men and women and multidimensional scaling was used to plot the distribution of diagnostic categories. In the male sample, patients appeared to cluster according to affective symptoms and the mood-congruence of psychotic symptoms. Four clusters were apparent, but were less evident in the female sample. This gender difference was given partial support by quantitative measures of concordance. It is suggested that women manifested a greater admixture of symptoms, especially mixed affective and psychotic symptoms, than men.     

精神分裂症与心境障碍诊断变更的特征比较

目的:探讨精神分裂症和心境障碍诊断相互变更的特征。方法:从10年间住院2次的786例病例中筛查出交替出现过心境障碍和精神分裂症诊断的患者93例,对其人口学资料和临床表现进行比较。结果:女性、家族史阴性、起病较早、首次病程短及心境障碍伴精神病性症状者较易变更诊断;起病年龄较大的首次诊断为精神分裂症患者,再次住院时易变更诊断为心境障碍。结论:精神分裂症的诊断并非固定不变,与心境障碍二者间可相互变更。     

Outcome of schizophrenia in India using various diagnostic systems

A group of 112 patients diagnosed to be suffering from schizophrenia according to ICD-9 concept of this disorder were followed-up for a period of 18-30 months. Five diagnostic systems for schizophrenia: CATEGO, Research Diagnostic Criteria, Feighner's Criteria, DSM-III and Schneider's First Rank Symptoms were also applied to the study group at the beginning of the investigation. The outcome was assessed in the areas of clinical improvement, course, severity of illness and work. The course of the disorder and outcome in various definitions did not reveal significant variability though patients diagnosed to be schizophrenics according to DSM-III tended to display more psychopathology and impaired work efficiency at the time of follow-up.     

Familial liability and schizophrenia phenotypes: a polydiagnostic approach

BACKGROUND: There are conflicting results about the correspondence between the diagnostic phenotype of schizophrenia and genetic factors. Using a polydiagnostic approach we examined the relationship between familial liability and alternative schizophrenia phenotypes. METHODS: The sample comprised of 660 psychotic probands and their 2987 first-degree relatives. Probands were assessed for 23 diagnostic systems of schizophrenia, 2 criteria for broadness of phenotype, 4 subtyping criteria and 16 clinical features, while relatives were assessed for familial morbid risk of schizophrenia. To quantify the predictive validity of familial liability against the alternative phenotypes we used the receiver operator characteristic curve analysis yielding an area under the curve (AUC) measure and logistic regression analysis. RESULTS: Although familial liability significantly predicted some diagnostic criteria for schizophrenia, their diagnostic performance was generally very poor (AUC .55 to .61 and OR 1.64 to 2.85). Overall, the most inclusive criteria performed better than the most restrictive ones. Subtyping schizophrenia according to both DSM-IV and negative or deficit subtypes was unrelated to familial liability. The best predictive ability of familial liability (AUC=.71, OR=4.54) was achieved against empirically-derived criteria consisting of (a) early onset or lack of a major mood syndrome and (b) presence of inappropriate affect, affective flattening or bizarre delusions. CONCLUSION: Familial liability does have poor predictive validity regarding diagnostic systems of schizophrenia, although some differences existed among systems. Liability to schizophrenia performed better in predicting broad than restrictive phenotypes of the disorder.     

Catatonic schizophrenia in Croatia

A representative sample of schizophrenic subjects was collected for epidemiological and clinical follow-up in 1972 from the pool of 8069 patients registered in the Croatian Psychotics Case Register (CPCR). This sample comprised 402 patients (207 males and 195 females), who were followed up until 1990/91. The diagnosis of schizophrenia, catatonic type according to ICD-8 (V/295.2), was made in 59 cases (14.7 %; 28 males, 31 females) at least once in the course of the follow-up. This study presents data concerning the diagnostic instability of the catatonic subtype during the long-term follow-up. As subtype diagnoses were frequently changed over the course of illness, at the end of the follow-up, the diagnosis of catatonic schizophrenia was only confirmed in 11 (18.6 %) cases. Positive family history of psychosis was found in 44.1 % of catatonic patients, a percent significantly greater than the corresponding figure for all non-catatonic schizophrenic subtypes combined (20.1 %). This study provides preliminary evidence that the catatonic subtype of schizophrenia is a separate diagnostic entity with a high familial loading.

     

Basal and haloperidol-stimulated prolactin in neuroleptic-free men with schizophrenia defined by 11 diagnostic systems

Forty-four male, neuroleptic-free, acutely psychotic patients with at least one diagnosis of schizophrenia among 11 diagnostic systems, and 28 healthy controls, underwent measurement of prolactin (PRL) concentrations before and after intravenous administration of haloperidol (0.5 mg). Basal PRL concentrations were lower in the patients with Research Diagnostic Criteria (RDC) DSM-III, Cloninger, and Taylor and Abrams schizophrenias than in controls. Compared with the controls, the PRL response to haloperidol was lower in the patients with schizophrenia defined by all diagnostic systems except those of Schneider and M. Bleuler. Neither basal nor stimulated PRL concentrations were correlated with positive symptoms, but basal PRL was correlated with the Brief Psychiatric Rating Scale (BPRS) depression-related subscore. This study lends further support for the presence of dopaminergic dysfunction in schizophrenia, and demonstrates the advantages and problems in the use of multidiagnostic psychopathological evaluation to categorize a disorder where there is major disagreement among diagnostic systems.     

Electroencephalographic findings in relation to diagnostic constructs in psychiatry

A group of 759 patients with final DSM-I and -II diagnoses of schizophrenia was identified among a cohort of 1494 adults who were hospitalized between 1965 and 1972. Admission EEG recordings were done in each patient during waking, activation procedures, drowsiness, and sleep. All cases were reclassified according to the Feighner et al. criteria, and relationships between the EEG, reassigned diagnosis, and outcome were examined. One-third of the schizophrenics were rediagnosed as having affective, organic, or other disorders. EEG abnormalities predicted diagnostic change and relatively favorable prognosis. Mean alpha frequencies were slower in schizophrenics than in patients with other DSM I-II disorders, and less in patients with Feighner et al. diagnoses of schizophrenia than in some rediagnosed categories. In 1980-82, matched samples from the original cohort with affective, schizophrenic, and mixed Feighner et al. diagnoses were followed and evaluated blindly with the SADS-L. RDC follow-up diagnoses were significantly correlated with the index EEG findings in terms of higher alpha average frequencies proportional to the amount of affective psychopathology. A subgroup of high functioning individuals within the RDC schizophrenic category was identified with affective symptomatology early in the course of illness, normal EEGs, and high alpha average frequencies. Patients with a consistent diagnosis of schizophrenia according to the three nosologic systems were shown to function better in some areas if the index EEG was abnormal. Discriminant function analysis established that DSM-I and -II categories possessed the greatest long-term predictive accuracy which was enhanced by the EEG diagnosis and alpha average to a level of more than 50%. The Feighner et al. and RDC diagnostic systems were not as relevant for prediction of long-term follow-up status.     

Are males more likely than females to develop schizophrenia?

OBJECTIVE: This study was undertaken to determine whether the incidence of schizophrenia is equivalent for males and females. METHOD: An attempt was made to identify every first-episode case of psychosis in a large Canadian city over a period of 2 1/2 years. A comprehensive referral network was established that included hospital and community settings where psychotic persons might appear. More than 300 potential subjects were identified, 175 of whom underwent a structured psychiatric interview and were assigned diagnoses according to five different diagnostic systems. RESULTS: The incidence of schizophrenia was two to three times higher among males than among females. Even though the use of different diagnostic systems yielded slightly different risk rates, the elevated risk for males remained consistent. There were no differences between the sexes in the incidence of affective psychosis. In comparison with schizophrenia, the incidence rates for mood disorders with psychotic features were sometimes lower and sometimes higher, depending on the diagnostic system used. CONCLUSIONS: The findings, coupled with reports in the past 10 years from other investigators, challenge the conventional belief that the incidence of schizophrenia is the same for the two sexes.     

Diagnostic systems for schizophrenia. A cross-sectional study of concordance from India

In a cross-sectional study, five diagnostic systems for schizophrenia: CATEGO, Research Diagnostic Criteria, DSM-III, Feighner's Criteria, and Schneider's First Rank Symptoms, were evaluated for their usefulness, comprehensiveness and concordance, using a clinical diagnosis conforming to the ICD-9 concept of schizophrenia. The sample consisted of 112 patients. It was found that all the diagnostic systems had good agreement with the index diagnosis. The rate of concordance among the systems varied. The advantages and limitations of each system and its usefulness in Indian context are discussed.     

Psychometric properties of a performance-based measurement of functional capacity, the UCSD Performance-based Skills Assessment - Brief version

The UCSD Performance-based Skills Assessment - Brief version (UPSA-B) describes the functions of patients without negative influences of environmental factors such as unemployment or shortage in housing. The aim of the present study is to further explore the psychometric properties of the UPSA-B as well as to ensure that the Swedish version can be used in clinical practice and for research purposes. Participants were 211 patients, 135 men and 76 women, diagnosed with schizophrenia, schizoaffective disorder, or delusional disorder. Results indicate that the UPSA-B is a reliable instrument with good psychometric properties regarding validity and reliability. The instrument also had a capacity to reveal differences between various patient groups, both diagnostic groups and groups based on remission status. The conclusion drawn is that the UPSA-B is a valuable instrument that could be used in future cross-national studies to describe the level of functioning for patients with schizophrenia and other psychotic illnesses.     

First rank symptoms: concepts and diagnostic utility

First Rank Symptoms (FRS) were first defined by Schneider as diagnostic of schizophrenia. Since then, there has been an immense debate on their diagnostic and prognostic utility. This review attempts to understand the concepts of FRS as depicted over the years and the diagnostic and prognostic implications of FRS in mental illnesses including schizophrenia. Review of relevant material showed that there are wide variations in the concepts of FRS which may be classified according to broad and narrow definitions. These variations have also led to the differences in the diagnostic systems currently being used. Although the diagnostic utility of FRS in schizophrenia remains, it is not clearly so with other mental illnesses in which these symptoms may also be observed. In addition there is controversy over the prognostic implications with evidence divided between poor and no influence on outcome.