Clinical and psychometric validation of the psychotic depression assessment scale.

BACKGROUND: Recent studies have indicated that the 11-item Psychotic Depression Assessment Scale (PDAS), consisting of the 6-item melancholia subscale (HAM-D6) of the Hamilton Depression Rating Scale and 5 psychosis items from the Brief Psychiatric Rating Scale (BPRS), is a valid measure for the severity of psychotic depression. The aim of this study was to subject the PDAS, and its depression (HAM-D6) and psychosis (BPRS5) subscales to further validation. METHODS: Patients diagnosed with psychotic depression at Danish psychiatric hospitals participated in semi-structured interviews. Video recordings of these interviews were assessed by two experienced psychiatrists (global severity rating of psychotic depression, depressive symptoms and psychotic symptoms) and by two young physicians (rating on 27 symptom items, including the 11 PDAS items). The clinical validity and responsiveness of the PDAS and its subscales was investigated by Spearman correlation analysis of the global severity ratings and the PDAS, HAM-D6, and BPRS5 total scores. The unidimensionality of the scales was tested by item response theory analysis (Mokken). RESULTS: Ratings from 39 participants with unipolar psychotic depression and nine participants with bipolar psychotic depression were included in the analysis. The Spearman correlation analysis indicated that the PDAS, HAM-D6 and BPRS5 were clinically valid (correlation coefficients from 0.78 to 0.85, p<0.001) and responsive (correlation coefficients from 0.72 to 0.86, p<0.001) measures of psychotic depression. According to the Mokken analysis, all three scales were unidimensional. CONCLUSIONS: The clinical validity, responsiveness and unidimensionality of the PDAS and its subscales were confirmed in an independent sample of patients with psychotic depression.

The validity of the schizophrenia diagnosis in the Danish Psychiatric Central Research Register is good.

INTRODUCTION: The Danish Psychiatric Central Research Register (DPCRR) has been used extensively for research purposes during the past decades. The aim of this study was to investigate the validity of the International Classification of Diseases (ICD)-10 schizophrenia diagnosis in the DPCRR. MATERIAL AND METHODS: A random sample of 300 patients with a first-time diagnosis of schizophrenia (ICD-10 codes F20.0-F20.3 and F20.9) in 2009 was drawn from the register to assess its validity. The case records were reviewed by a Schedules for Clinical Assessment in Neuropsychiatry-certified psychiatric resident using the ICD-10 diagnostic criteria as reference. RESULTS: The sample of 300 patients with schizophrenia represented 23.3% of all incident cases (n = 1,288) registered in 2009. We obtained 291 (97.0%) of the case records (nine were lost or inaccessible). Two case records (0.7%) were excluded because of foreign citizenship as these patients had prior episodes in other countries. Thirteen cases (4.3%) were erroneously registered as schizophrenia in the DPCRR. Of the remaining 276 patients, 269 (97.5%) fulfilled the ICD-10 diagnostic criteria for schizophrenia. In a worst case model including all 300 case records, the validity of the schizophrenia diagnosis was 89.7%. CONCLUSION: According to this assessment of patient case records, the diagnosis of schizophrenia in the DPCRR has a high validity and is well-suited for research. FUNDING: Aalborg Psychiatric Hospital funded the study, but the institution had no influence on the planning of the study or the preparation of the manuscript. TRIAL REGISTRATION: not relevant.

Characteristics and predictors of long-term institutionalization in patients with schizophrenia.

BACKGROUND: Patients with schizophrenia requiring long-term institutionalization represent those with the worst outcome, leading to personal costs for patients and relatives and constituting a large economical burden for society. AIM: To identify characteristics and predictors of outcome of institutionalized patients with schizophrenia. METHOD: One-year follow-up cohort study, utilizing the Danish national registers, of all institutionalized and non-institutionalized patients with schizophrenia in Denmark with an ICD-10 lifetime diagnosis of schizophrenia (F20.0-F20.9) since 1969 and alive at the index date of January 1st 2006 (total number 22,395). RESULTS: Compared with non-institutionalized patients, institutionalized patients (n=2188; 9.8%) had earlier onset of schizophrenia and lower scholastic achievements, were more often diagnosed with a hebephrenic subtype (odds ratio (OR), 2.34; 95% confidence interval (CI), 1.95-2.80; p<0.001), received higher dosages of antipsychotics, more antipsychotic polypharmacy and more concomitant medications, and had more substance misuse and early retirement pension. In a logistic regression model adjusted for sex and age, institutionalized patients with schizophrenia had an increased risk of type II diabetes (AOR, 1.22; CI, 1.01-1.42; p<0.001), but the mean age of onset of type II diabetes did not differ. The mean patient age was higher in the institutionalized group (62.7 vs. 58.7 years; p=0.027), which was mainly driven by absence of death from suicide in the institutionalized group. Multivariate predictors of institutionalization included hebephrenic subtype, a diagnosis of epilepsy, early retirement pension, male sex, a greater proportion of prior hospitalization, and substance misuse. CONCLUSIONS: Institutionalized patients with schizophrenia had a more complex and worse outcome of the disorder, except for less suicide, illustrated by lower scholastic achievement, receiving higher dosages of antipsychotic medications, more concomitant medications and more prior bed-days.