Psychometric properties and a latent class analysis of the 12‐item World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) in a pooled dataset of community samples

The 12‐item World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) is a brief measurement tool used cross‐culturally to capture the multi‐dimensional nature of disablement through six domains, including: understanding and interacting with the world; moving and getting around; self‐care; getting on with people; life activities; and participation in society. Previous psychometric research supports that the WHODAS 2.0 functions as a general factor of disablement. In a pooled dataset from community samples of adults (N = 447) we used confirmatory factor analysis to confirm a one‐factor structure. Latent class analysis was used to identify subgroups of individuals based on their patterns of responses. We identified four distinct classes, or patterns of disablement: (1) pervasive disability; (2) physical disability; (3) emotional, cognitive, or interpersonal disability; (4) no/low disability. Convergent validity of the latent class subgroups was found with respect to socio‐demographic characteristics, number of days affected by disabilities, stress, mental health, and substance use. These classes offer a simple and meaningful way to classify people with disabilities based on the 12‐item WHODAS 2.0. Focusing on individuals with a high probability of being in the first three classes may help guide interventions.     

Modeling the World Health Organization Disability Assessment Schedule II using non‐parametric item response models

The World Health Organization Disability Assessment Schedule II (WHO‐DAS II) is a multidimensional instrument developed for measuring disability. It comprises six domains (getting around, self‐care, getting along with others, life activities and participation in society). The main purpose of this paper is the evaluation of the psychometric properties for each domain of the WHO‐DAS II with parametric and non‐parametric Item Response Theory (IRT) models. A secondary objective is to assess whether the WHO‐DAS II items within each domain form a hierarchy of invariantly ordered severity indicators of disability. A sample of 352 patients with a schizophrenia spectrum disorder is used in this study. The 36 items WHO‐DAS II was administered during the consultation. Partial Credit and Mokken scale models are used to study the psychometric properties of the questionnaire. The psychometric properties of the WHO‐DAS II scale are satisfactory for all the domains. However, we identify a few items that do not discriminate satisfactorily between different levels of disability and cannot be invariantly ordered in the scale. In conclusion the WHO‐DAS II can be used to assess overall disability in patients with schizophrenia, but some domains are too general to assess functionality in these patients because they contain items that are not applicable to this pathology. Copyright © 2014 John Wiley & Sons, Ltd.     

Psychometric properties of the World Health Organization Disability Assessment Schedule used in the European Study of the Epidemiology of Mental Disorders

This study assessed the factor structure, internal consistency, and discriminatory validity of the World Health Organization Disability Assessment Schedule (WHODAS) version used in the European Study of the Epidemiology of Mental Disorders (ESEMeD). In total 8796 adults were assessed using the ESEMeD WHODAS (22 severity and 8 frequency items). An Exploratory Factor Analysis (EFA) with promax rotation was done with a random 50%. The other half was used for confirmatory factor analysis (CFA) comparing models (a) suggested by EFA; (b) hypothesized a priori; and (c) reduced with four items. A CFA model with covariates was conducted in the whole sample to assess invariance across Mediterranean (Spain, France and Italy) and non-Mediterranean (Belgium, Germany and the Netherlands) countries. Cronbach's alphas and discriminatory validity were also examined. EFA identified seven factors (explained variance: 80%). The reduced model (six factors, four frequency items excluded) presented the best fit [Confirmatory Fit Index (CFI) = 0.992, Tucker-Lewis Index (TLI) = 0.996, Root Mean Square Error of Approximation (RMSEA) = 0.024]. The second-order factor structure also fitted well (CFI = 0.987, TLI = 0.991, RMSEA = 0.036). Measurement non-invariance was found for Embarrassment. Cronbach's alphas ranged from 0.84 for Participation to 0.93 for Mobility. Preliminary data suggest acceptable discriminatory validity. Thus, the ESEMeD WHODAS may well be a valuable shortened version of the WHODAS-II, but future users should reconsider the filter questions.     

Mapping of the World Health Organization's Disability Assessment Schedule 2.0 to disability weights using the Multi‐Country Survey Study on Health and Responsiveness

ObjectivesTo develop and test an internationally applicable mapping function for converting WHODAS‐2.0 scores to disability weights, thereby enabling WHODAS‐2.0 to be used in cost‐utility analyses and sectoral decision‐making.MethodsData from 14 countries were used from the WHO Multi‐Country Survey Study on Health and Responsiveness, administered among nationally representative samples of respondents aged 18+ years who were non‐institutionalized and living in private households. For the combined total of 92,006 respondents, available WHODAS‐2.0 items (for both 36‐item and 12‐item versions) were mapped onto disability weight estimates using a machine learning approach, whereby data were split into separate training and test sets; cross‐validation was used to compare the performance of different regression and penalized regression models. Sensitivity analyses considered different imputation strategies and compared overall model performance with that of country‐specific models.ResultsMapping functions converted WHODAS‐2.0 scores into disability weights; R‐squared values of 0.700–0.754 were obtained for the test data set. Penalized regression models reached comparable performance to standard regression models but with fewer predictors. Imputation had little impact on model performance. Model performance of the generic model on country‐specific test sets was comparable to model performance of country‐specific models.ConclusionsDisability weights can be generated with good accuracy using WHODAS 2.0 scores, including in national settings where health state valuations are not directly available, which signifies the utility of WHODAS as an outcome measure in evaluative studies that express intervention benefits in terms of QALYs gained.     

Disability in schizophrenia: clinical correlates and prediction over 1-year follow-up

Schizophrenia may cause disability leading to restrictions on many domains of daily life such as hygiene, self-management, vocational and leisure activities, and family and social relationships. The aim of this study was to assess the level of disability with the Brief Disability Questionnaire (BDQ), developed by the World Health Organization, and to identify the clinical correlates and predictors of disability during a 1-year follow-up period in 382 patients with schizophrenia. All patients were assessed at the beginning of the study, and 168 (44%) of them were re-evaluated after 1 year. Total disability scores of the patients with schizophrenia were significantly decreased at follow-up. Female patients seemed to be more disabled than males. Disability showed a positive correlation with the total, positive symptoms and negative symptoms scores on the Brief Psychiatric Rating Scale, as well as scores on the UKU Side Effects Rating Scale. Patients with the disorganized subtype of schizophrenia and residual symptoms were more disabled than patients with other subtype diagnoses. Negative symptoms and duration of untreated psychosis were significant predictors of disability after 1 year. Early-onset schizophrenia had a twofold increased risk for developing disability. Disability in schizophrenia is a clinical phenomenon closely linked to negative symptoms and poor outcome.     

Mortality among homeless people with schizophrenia in Sydney, Australia: a 10-year follow-up

OBJECTIVE: The aims were first, to describe deaths in a cohort of homeless people compared to the general population and secondly, to compare deaths among the individuals with schizophrenia to those without schizophrenia. METHOD: Mortality was assessed in a cohort of 708 homeless subjects, 506 with schizophrenia who were referred 10 years previously to psychiatric outreach clinics. Standardized mortality ratios (SMRs) were calculated. RESULTS: Eighty-three people (12%) had died, 19 from suicide. The SMR was 3.76 for homeless men and 3.14 for homeless women. There was a non-significant trend for higher excess mortality among men without schizophrenia compared to men with schizophrenia. SMRs for suicide were significantly elevated among homeless men. CONCLUSION: Homeless people in inner Sydney have death rates three to four times higher than people in the general population of New South Wales. Excess mortality was greatest for younger age groups.     

The World Health Organization Short Disability Assessment Schedule (WHO DAS-S): a tool for the assessment of difficulties in selected areas of functioning of patients with mental disorders

The World Health Organization Short Disability Assessment Schedule (WHO DAS-S) is an instrument for clinicians' assessment and rating of difficulties in maintaining personal care, in performing occupational tasks and in functioning in relation to the family and the broader social context due to mental disorders. The WHO DAS-S was developed and underwent preliminarily testing in the context of two international field trials of the multiaxial presentation of ICD-10 for use in adult psychiatry. The instrument was found to be useful, user-friendly and reasonably reliable for use by clinicians belonging to different schools of psychiatry and psychiatric traditions. Further work on the WHO DAS-S should include development of national adaptations of the instrument, studies of concurrent validity of the instrument and modification of the instrument to accommodate changes in the next edition of the International Classification of Impairments, Disabilities and Handicaps (ICIDH).     

Repeated naloxone administration in schizophrenia: a phase II World Health Organization Study

In the context of a previous WHO collaborative study, six research centers reported that naloxone (0.3 mg/kg) produced significant improvement in symptomatology in neuroleptic-treated patients. In the current Phase II WHO study, repeated (4 days) naloxone (0.3 mg/kg) administration was performed in schizophrenic patients (n = 43) from five WHO collaborating centers using a double-blind, placebo-controlled design. Both naloxone and placebo administrations were associated with significant reductions in symptoms. Naloxone, however, was not superior to placebo. These data are discussed in relation to endorphin hypotheses of schizophrenia.     

Social outcome in schizophrenia: a 13-year follow-up

Summary The cohort consists of all psychiatric patients (n=53) admitted for the first time in 1972 from a welldefined catchment area with a population of 582,000 inhabitants aged 15 years and over. Furthermore, they were all registered with the diagnosis schizophrenia in the nation-wide psychiatric register at least once during an observation period from the day of the first admission in 1972 until August 31, 1983. The entire cohort was followed up on average 13 years after their first admission. Poor employment outcome (79%), poor social contact outcome (55%), and poor overall social outcome (76%) characterized the living conditions of the 42 patients alive at follow-up. Good employment outcome was predicted by born in rural area. Good social contact outcome was predicted by full remission at first discharge and poor outcome by male sex. Good overall social outcome was predicted by born in rural area and of marginal significance by high social status at first admission. A comparison of parents' highest social group and patients' social group at follow-up supports previous findings on social drift.     

A five-year follow-up study of older long-stay clients with intellectual disability using the Disability Assessment Schedule

The emphasis on community care means closure of the long-stay institutions for people with intellectual disability. Studies have indicated that older people with intellectual disability in particular may not be adequately cared for because of poor monitoring of their changing needs and inadequate provision of services. The use of rating instruments to monitor changes, and to predict outcome or needs in this population may help to improve care by assisting with planning and projection of service requirements. In 1991, all residents of a long-stay hospital for people with intellectual disability were assessed using the Disability Assessment Schedule (DAS). Five years later, the 1991 scores of the older residents (aged > 50 years) were reviewed and compared under three outcome groups: in-patients, discharged and deceased. Furthermore, all older people resident in the hospital in 1996 were reassessed using the DAS. Out of the 144 older clients resident in 1991, five years later, 78 were still in-patients, 38 had been discharged into the community and 28 were deceased. In 1991, the deceased group had the greatest problems with continence and symbolic behaviour, while the discharged group had the greatest problems with self-help, vision, hearing, communication, social interaction, echolalia and repetitive speech. In comparison with 1991, the 1996 DAS scores of older residents showed that there were increasing problems with vision, hearing, communication, behaviour and symbolic activities. The present study suggested that the DAS is a useful instrument for monitoring change and predicting outcome in older people with intellectual disability.     

Outcome in males with first-episode schizophrenia: 7-year follow-up

Abstract

Family, twin, and segregation analytic studies indicate a complex genetic contribution to panic disorder with an estimated heritability of 48%. Angiotensin-converting enzyme (ACE) degrades substance P, which has been implicated in anxiety-related behaviour. ACE has been suggested as a potential risk factor in the pathogenesis of panic attacks. A functional insertion deletion (I/D) polymorphism in the ACE gene was suggested to be associated with panic disorder in a potentially gender-specific way (). The present study aimed to replicate this finding and thereby to further elucidate the role of ACE gene variation in the pathomechanism of panic disorder. The ACE I/D polymorphism was genotyped in a sample of 102 German patients with panic disorder with or without agoraphobia as well as a healthy German control group matched with regard to age and sex (n = 102). In the male subgroup (n = 43) of panic patients a significant association of the ACE I allele (P = 0.0474) and genotypes containing the I allele (P = 0.0195), respectively, was observed. The present results provide further support for a potentially male-specific role of the less active ACE I allele in the pathogenesis of panic disorder, possibly by altering substance P levels.     

Predictors of changes in caregiving burden in people with schizophrenia: a 3-year follow-up study in a community mental health service

OBJECTIVE: The aims of this study were to measure changes over 3-years in caregiving burden and emotional distress in relatives of people with schizophrenia and to identify factors predicting the levels of caregiving burden. METHOD: A cohort of 51 caregivers of patients with schizophrenia attending the South-Verona Community Mental Health Service was assessed over 3-years with the Involvement Evaluation Questionnaire, European Version. Predictors of caregiving burden included both caregivers' and patients' characteristics and patterns of carer-patient interaction. RESULTS: Baseline levels of family burden were high in worrying and urging domains. Fifty-one per cent of caregivers experienced significant emotional distress. Both overall burden and emotional distress improved. Higher patients' psychopathology, higher numbers of patient-rated needs, patients' lower global functioning and patients' poorer quality of life were found to be related to the severity of family burden. The only significant predictor of caregivers' burden at follow-up was the baseline level of caregivers' burden itself. CONCLUSION: A policy addressing the caring burden of informal caregivers beyond patients' symptoms reduction should be considered.     

The Maudsley early onset schizophrenia study: cognitive function over a 4-year follow-up period

Generalized cognitive deficits have been consistently reported in adolescents with early onset schizophrenia (EOS; defined as onset before the age of 17 years). The impact on cognition of potential interactions between disease pathology and brain maturation remains unclear. We therefore compared cognitive function between 20 EOS patients and 20 healthy controls matched on age, gender, and parental socioeconomic status at 2 time points, when aged 15.58 (2.27) and after a mean interval of 4 +/- 1.08 years when aged 19.46 (2.21) years. Repeated measures analyses revealed no differences between patients and controls in the degree of change over this time period in general intellectual function and planning ability as measured by the Tower of London. There was deterioration in the verbal memory and attentional control index scores from the Wechsler Memory Scale-Revised but relative improvement in Part A of the Trail Making Test. Patients' level of symptomatology as well as the type and dose of medication were comparable at both time points. We conclude that most aspects of cognitive function remain relatively stable in EOS patients during adolescence; there is evidence for deterioration in immediate verbal memory and attention while speed of information processing may show improvement.     

Social functioning and neurocognitive deficits in outpatients with schizophrenia: a 2-year follow-up

Neurocognitive deficits have been associated with the social functioning impairments of patients with schizophrenia. More information is needed about how cognitive status and other variables predict social functioning over defined periods of time. In this study, 72 relatively stable outpatients with schizophrenia were compared between baseline and a 2-year follow-up on measures of social functioning. Patients were also assessed with a battery of neurocognitive tests and the Positive and Negative Syndrome Scale. Results were compared by univariate and multivariate analyses. A total of four out of seven subscales of the Social Functioning Scale (SFS) and the total SFS score did not show a significant change over the 2-year period. On the three SFS subscales that did show a significant change, residual change scores were correlated with better neurocognitive performance at baseline, younger age, and shorter illness duration. For the Multnomah Community Ability Scale, 48.9% of the total score at follow-up was predicted by initial negative symptoms and scores on the Aphasia Screening Test. These results document the independent contribution of demographic variables, negative symptoms, and neurocognitive deficits to the social functioning impairments of individuals with schizophrenia.     

Remission in schizophrenia: a community-based 6-year follow-up study in Bali

Aim: The purpose of this naturalistic study was to investigate the rate and predictors of remission at medium‐term follow up of individuals with schizophrenia in a community setting in Bali. Methods: Subjects comprised 37 individuals with schizophrenia, including 19 never‐treated cases, screened from 8546 general residents. Outcome was evaluated using the standardized symptomatic remission criteria based on Positive and Negative Syndrome Scale scores and operational functional remission criteria at 6‐year follow up. Results: Ten individuals (27%) achieved symptomatic remission, 12 (32%) achieved functional remission, and 10 (27%) achieved complete remission (i.e. symptomatic and functional remission). Lower Positive and Negative Syndrome Scale negative symptom score at baseline and receipt of psychiatric treatment for more than half of the follow‐up period were predictors of complete remission. Conclusions: The majority of community‐screened individuals with schizophrenia failed to achieve complete remission at the 6‐year follow up. These results suggest that strategies promoting mental health service utilization among individuals with schizophrenia are essential in Bali.     

Life expectancy of people with intellectual disability: a 35-year follow-up study

A 35‐year follow‐up study based on a nation‐wide population study of the life expectancy of people with intellectual disability (ID) was undertaken. The study population consisted of a total of 60969 person‐years. A prospective cohort study with mortality follow‐up for 35 years was used and the life expectancy of people with ID was calculated for different levels of intelligence. Proportional hazard models were used to assess the influence of level of intelligence and associated disorders on survival. People with mild ID did not have poorer life expectancy than the general population and subjects with mild ID did not have lower life expectancy in the first 3 decades of life. In cases with profound ID, the proportion of expected life lost was > 20% for almost all age groups. The female preponderance was manifested from the age of 60 years onwards, 25 years later than in the general population. Respectively, survival between sexes differed less. Epilepsy and/or hearing impairment increased the relative risk of death for all levels of ID. The prevalence of people with ID over 40 years was 0.4%. People with ID now live longer than previously expected, and the ageing of people with mild ID appears to be equal to that of the general population, posing new challenges to health care professionals.