The reliability of psychiatric diagnosis in Israel's Psychiatric Case Register

Predictors of Disagreement Between Diagnoses From Consult Requesters and Consultation-Liaison Psychiatry

We evaluated disagreement between reported symptoms and a final diagnosis of depression, anxiety, withdrawal, psychosis, or delirium through regression models assessing individual and combined diagnoses. Highest disagreement rates were reported for services classified as others (88.2%), general surgery (78.5%), and bone marrow transplant (77.7%). Disagreement rates varied widely across different diagnoses, with anxiety having the highest disagreement rate (63.3%), whereas psychosis had the lowest disagreement rate (10.6%). When evaluating kappa coefficients, the highest agreement occurred with diagnoses of withdrawal and psychosis (0.66% and 0.51%, respectively), whereas anxiety and depression presented the lowest values (0.31% and 0.11%, respectively). The best-performing predictive model for most outcomes was random forest, with the most important predictors being specialties other than the ones focused on single systems, older age, lack of social support, and the requester being a resident. Monitoring disagreement rates and their predictors provides information that could lead to quality improvement and safety programs.

Validation study of the early onset schizophrenia diagnosis in the Danish Psychiatric Central Research Register

The objective of this study is to assess (1) the concordance and validity of schizophrenia register diagnoses among children and adolescents (early onset schizophrenia = EOS) in the Danish Psychiatric Central Research Register (DPCRR), and (2) the validity of clinical record schizophrenia diagnoses. Psychiatric records from 200 patients with a first-time diagnosis of schizophrenia (F20.x) at age < 18 years between 1994 and 2009 in the DPCRR were rated by experienced clinicians according to ICD-10 criteria, using a predefined checklist. We retrieved 178 records, representing 19.6% of all patients diagnosed with EOS from 1994 to 2009. Mean age was 15.2 years and 56.2% were males. The register-based and clinical diagnoses matched in 158 cases (88.8%). Raters' diagnoses confirmed the DPCRR schizophrenia diagnoses in 134 cases, rendering a diagnostic validity of 75.3% of DPCRR schizophrenia, while 149 cases were confirmed as being in the schizophrenia spectrum (83.7%). When removing records with registration errors, 83.5% of cases were confirmed as schizophrenia and 91.8% as being in the schizophrenia spectrum. Interrater reliability was substantial with Cohen's kappa > 0.78-0.83 depending on classification. Compared to diagnoses made in outpatient settings, EOS diagnoses during hospitalizations were more likely to be valid and had fewer registration errors. Diagnosed in inpatient settings, EOS diagnoses are reliable and valid for register-based research. Schizophrenia diagnosed in children and adolescents in outpatient settings were found to have a high number of false-positives, both due to registration errors and diagnostic practice. Utilizing this knowledge, it is possible to reduce the number of false-positives in register-based research of EOS.

Setting up a psychiatric case register

Case registers have very little to do with computers or any other form of mechanical calculating machine. To write an article on case registers which concentrated on information technology would be as logical as an article on open heart surgery which confined itself to the finer points of scalpel technology. The creation of a case register is as simple or as complicated as the clinician wishes it to be; a case register at its purest is simply a list of contacts with patients, organised to a predetermined format, which allows the clinician to gain information from the list for education, research, planning or administration. The work needed to establish a case register, however, should not be underestimated, and the time spent in thinking through reasons for development of a register is a worthwhile investment. An understanding of the history of the development of psychiatric case registers may help those wishing to develop new registers to avoid treading well worn cul-de-sacs, while reviewing some of the work which has resulted from case registers may demonstrate the enormous potential of a well-designed register in facilitating the extension of knowledge about treatment and provision of services.

Comparing algorithms for deriving psychosis diagnoses from longitudinal administrative clinical records

PURPOSE

Registers derived from administrative datasets are valuable tools in psychosis research, but diagnostic accuracy can be problematic. We sought to compare the relative performance of four methods for assigning a single diagnosis from longitudinal administrative clinical records when compared with reference diagnoses.

METHODS

Diagnoses recorded in inpatient and community mental health records were compared to research diagnoses of psychotic disorders obtained from semi-structured clinical interviews for 289 persons. Diagnoses were derived from administrative datasets using four algorithms; 'At least one' diagnosis, 'Last' or most recent diagnosis, 'Modal' or most frequently occurring diagnosis, and 'Hierarchy' in which a diagnostic hierarchy was applied. Agreements between algorithm-based and reference diagnoses for overall presence/absence of psychosis and for specific diagnoses of schizophrenia, schizoaffective disorder, and affective psychosis were examined using estimated prevalence rates, overall agreement, ROC analysis, and kappa statistics.

RESULTS

For the presence/absence of psychosis, the most sensitive and least specific algorithm ('At least one' diagnosis) performed best. For schizophrenia, 'Modal' and 'Last' diagnoses had greatest agreement with reference diagnosis. For affective psychosis, 'Hierarchy' diagnosis performed best. Agreement between clinical and reference diagnoses was no better than chance for diagnoses of schizoaffective disorder. Overall agreement between administrative and reference diagnoses was modest, but may have been limited by the use of participants who had been screened for likely psychosis prior to assessment.

CONCLUSION

The choice of algorithm for extracting a psychosis diagnosis from administrative datasets may have a substantial impact on the accuracy of the diagnoses derived. An 'Any diagnosis' algorithm provides a sensitive measure for the presence of any psychosis, while 'Last diagnosis' is more accurate for specific diagnosis of schizophrenia and a hierarchical diagnosis is more accurate for affective psychosis.

Classification of bipolar disorder in psychiatric hospital. A prospective cohort study

BACKGROUND

This study has explored the classification of bipolar disorder in psychiatric hospital. A review of the literature reveals that there is a need for studies using stringent methodological approaches.

METHODS

480 first-time admitted patients to psychiatric hospital were found eligible and 271 of these gave written informed consent. The study sample was comprised of 250 patients (52%) with hospital diagnoses. For the study, expert diagnoses were given on the basis of a structured diagnostic interview (M.I.N.I.PLUS) and retrospective review of patient records.

RESULTS

Agreement between the expert's and the clinicians' diagnoses was estimated using Cohen's kappa statistics. 76% of the primary diagnoses given by the expert were in the affective spectrum. Agreement concerning these disorders was moderate (kappa ranging from 0.41 to 0.47). Of 58 patients with bipolar disorder, only 17 received this diagnosis in the clinic. Almost all patients with a current manic episode were classified as currently manic by the clinicians. Forty percent diagnosed as bipolar by the expert, received a diagnosis of unipolar depression by the clinician. Fifteen patients (26%) were not given a diagnosis of affective disorder at all.

CONCLUSIONS

Our results indicate a considerable misclassification of bipolar disorder in psychiatric hospital, mainly in patients currently depressed. The importance of correctly diagnosing bipolar disorder should be emphasized both for clinical, administrative and research purposes. The findings questions the validity of psychiatric case registers. There are potential benefits in structuring the diagnostic process better in the clinic.

The psychiatric case register: noble past, challenging present, but exciting future

Case registers have been fundamental to mental health research from the early asylum studies onwards. Having declined in popularity over the past 20 years, they are likely to see a resurgence of interest with the advent of electronic clinical records and the technological capacity to derive anonymised databases from these.

Administrative registers in psychiatric research: a systematic review of validity studies

OBJECTIVE

To conduct a systematic review of studies investigating the validity of administrative registers for use in psychiatric research.

METHOD

Studies were identified using MEDLINE (1966-2004) and EMBASE (1980-2004) databases using keywords 'validity' or 'reliability' combined with 'register' or 'database$'. Studies reviewed by two raters blind to each other and quality assessed using a data extraction form devised by the authors. A narrative description of the findings is presented.

RESULTS

Fourteen studies were identified, seven of which concerned Scandinavian registers. Ten studies were solely concerned with diagnostic validity and the most common single diagnosis studied was schizophrenia (five studies). Methods used and study quality varied widely.

CONCLUSION

Given the importance of the area, relatively little high-quality work exists into systematically measuring the diagnostic data validity of registers for research purposes.

Cancer in schizophrenia: is the risk higher or lower?

Studies exploring the relationship between schizophrenia and cancer have shown conflicting results. Our study explores this association in three Jewish-Israeli population groups defined by their continent/place of birth (Israel, Europe-America, and Africa-Asia). The identification of the patients was made through the linkage of the nationwide psychiatric and cancer registries. The incidence of cancer in patients diagnosed with schizophrenia was compared with the incidence in the general population. The results showed that the cancer standardized incidence ratios (SIRs) for all sites were significantly lower among men and women with schizophrenia, 0.86 [95% confidence interval (CI) 0.80-0.93] and 0.91 (95% CI 0.85-0.97), respectively. This reduced overall risk was clearest for those born in Europe-America, both men (SIR 0.85, 95% CI 0.74-0.97) and women (SIR 0.86, 95% CI 0.77-0.94). Among women diagnosed with schizophrenia, the SIR was statistically higher for cancer in the breast among those born in Asia-Africa (1.37, 95% CI 1.12-1.63) and in the corpus uteri among the Israel-born (2.75, 95% CI 1.69-3.81) than among their counterparts in the general population. Lung cancer was significantly higher in men born in Asia-Africa diagnosed with schizophrenia than in the respective comparison population group (1.58, 95% CI 1.13-2.2). Our findings, and those of the literature, justify conducting a multinational study that includes identification of cancer-related risk factors among patients with schizophrenia and their families, and information on the use of psychotropic medications. This effort may clarify an epidemiological puzzle that remains outstanding.

An epidemiological study of mental disorders in a 10-year cohort of young adults in Israel

This is an overview of a two-phase epidemiological study of mental disorders among young adults in a ten-year birth cohort (1949-58) conducted in Israel. A sample of 4914 Israel-born offspring of Jewish immigrants was obtained by full probability sampling procedures and screened for caseness using psychometric symptom scales from the Psychiatric Epidemiology Research Interview (PERI). Those screened positive and almost a fifth of the negatives (N = 2741) were interviewed by psychiatrists using the Schedule for Affective Disorders and Schizophrenia, Israel version (SADS-I), in order to determine prevalence rates of specific disorders as defined by the Research Diagnostic Criteria (RDC). The completion rates for each interview phase were 94.5% and 90.7% respectively. Six-month prevalence rates are presented by gender, ethnic origin, and education. Approximately one-fifth of the birth cohort met current RDC criteria for a disorder at the definite level, excluding the RDC category of 'other psychiatric disorder'. Generalized anxiety disorder and major depressive disorder were the most commonly found types. The striking findings centre on alcoholism and drug use disorder which were exceedingly rare, and the unusually similar rates of major depression for males and females. The results from this study are discussed in comparison with those obtained from other epidemiological studies.

DSM-III in Ethiopia: a feasibility study

A feasibility study of DSM-III on 40 Ethiopian visitors to a psychiatric outpatient clinic in Addis Ababa was carried out by a Dutch psychiatrist, with three of his Dutch colleagues. In spite of the highly idiosyncratic way in which Ethiopians present their complaints, the diagnostic criteria of DSM-III appeared to be useful to a certain extent. The outcome of an inter-rater reliability study was comparable with that of an American one. The results were congruent for the classes that are rather well-defined in the DSM-III, like the psychotic and affective disorders. This did not apply to the classes of the somatoform and factitious disorders. Possible reasons for this are discussed.

The case for psychiatric record linkage

Evaluation of regional psychiatric services is essential for effective and economical planning and requires a complete and accurate source of data about individuals in the system. Routinely collected statistics describe only events, and cannot link data about individuals over time. This is possible with record linkage systems (or case registers) which are systematic standardized data collections about individuals' contacts with specified facilities over time. Such data bases have a wide range of clinical, epidemiological and administrative functions. The confidentiality of such systems is of paramount importance and is maintained by several safeguards. There are numerous technical considerations in establishing and operating record linkage systems. A wide variety of studies have been produced from systems around the world. An ongoing collection of linked data is required for many types of research and particularly for service evaluation. In times of cost constraints and diminishing resources, it is essential to deliver psychiatric services in the most effective and cost efficient manner possible.