Psychometric Properties of the Spanish Version of Two Mental Health Outcome Measures: World Health Organization Disability Assessment Schedule II and Lehman’s Quality of Life Interview

Psychometric evaluation of the Swedish self-rated 36-item version of WHODAS 2.0 for use in psychiatric populations - using classical test theory

AIM

The aim of this study was to evaluate the reliability and validity of the Swedish version of the self-rated 36-item WHODAS 2.0 in patients from Swedish psychiatric outpatient settings, using classical test theory.

METHODS

The 36-item WHODAS 2.0, together with the Sheehan Disability Scale (SDS), was filled in by a sample of 780 participating psychiatric patients: 512 (65.6%) women, 263 (33.7%) men, and 5 (0.6%) who did not report any sex.

RESULTS

The internal consistency, measured by Cronbach's alpha, for the different domains of functioning were between 0.70 and 0.94, and interpreted as good. The confirmatory factor analysis (CFA) revealed two levels: the first level consisted of a general disability factor, while the second level consisted of the six domains of the scale, respectively. The model had borderline fit. There was a significant correlation between WHODAS 2.0 36-item and SDS (n = 395). The WHODAS 2.0 differed significantly between diagnostic groups.

CONCLUSION

The present study demonstrates that the Swedish self-rated 36-item version of WHODAS 2.0, within a psychiatric outpatient population, showed good reliability and convergent validity. We conclude that the self-rated 36-item Swedish version of WHODAS 2.0 can be used for valid interpretations of disability in patients with psychiatric health conditions.

Initial evaluation of the validity and reliability of the culturally adapted Spanish CaSUN (S-CaSUN)

PURPOSE

There is a dearth of knowledge and limited research on the needs of Hispanic male cancer survivors (HMCSs). There is a clear need for the development of culturally and linguistically adapted needs assessment tools that are valid and reliable for use among the growing HMCS population. Thus, the purpose of this paper is to describe the field testing and psychometric evaluation of the translated and culturally adapted Spanish Cancer Survivor Unmet Needs Measure (S-CaSUN).

METHODS

Hispanic male cancer survivors (n = 84) completed the Spanish CaSUN (S-CaSUN), the Hospital Anxiety and Depression Scale (HADS), and the Functional Assessment of Cancer Therapy-General Population (FACT-GP). Construct validity of the S-CaSUN was assessed by correlation analysis among aforesaid measures. A test-retest procedure with 2-week delay was used to examine reproducibility with a participant subsample (n = 50). Cronbach's alpha was computed to assess internal consistency of the S-CaSUN.

RESULTS

Construct validity of the S-CaSUN was estimated by moderate correlation with the HADS anxiety (r = 0.55, P < 0.001) and depression scales (r = 0.60, P < 0.001) and the FACT-GP (r = - 0.62, P < 0.001). The test-retest correlation coefficient for the S-CaSUN was 0.78. Cronbach's alpha was 0.96. Field testing yielded a mean S-CaSUN score of 38.3 (SD = 26.2); all needs and positive change items were endorsed.

CONCLUSION

Findings from field testing and preliminary psychometric evaluation of the S-CaSUN provide initial evidence of validity and reliability of the measure and highlight the importance of going beyond translation when adapting measures to take culture, literacy, and language into consideration.

IMPLICATIONS FOR CANCER SURVIVORS

Reliable, culturally, and linguistically valid instruments facilitate identification of unique unmet needs of Hispanic cancer survivors that, in turn, can be addressed with evidence-based interventions. As cancer centers continue to develop survivorship programs, the S-CaSUN may be useful for a growing group of cancer survivors.

Cultural adaptation of a supportive care needs measure for Hispanic men cancer survivors

OBJECTIVE

Research with ethnic minority populations requires instrumentation that is cultural and linguistically relevant. The aim of this study was to translate and culturally adapt the Cancer Survivor Unmet Needs measure into Spanish.

METHODS

We describe the iterative, community-engaged consensus-building approaches used to adapt the instrument for Hispanic male cancer survivors. We used an exploratory sequential mixed method study design. Methods included translation and back-translation, focus groups with cancer survivors (n = 18) and providers (n = 5), use of cognitive interview techniques to evaluate the comprehension and acceptability of the adapted instrument with survivors (n = 12), ongoing input from the project's community advisory board, and preliminary psychometric analysis (n = 84).

RESULTS

The process emphasized conceptual, content, semantic, and technical equivalence. Combining qualitative and quantitative approaches offered a rigorous, systematic, and contextual approach to translation alone and supports the cultural adaptation of this measure in a purposeful and relevant manner.

CONCLUSION

Our findings highlight the importance of going beyond translation when adapting measures for cross-cultural populations and illustrate the importance of taking culture, literacy, and language into consideration.

World Health Organization disability assessment schedule 2.0: An international systematic review

PURPOSE

This systematic review examines research and practical applications of the World Health Organization Disability Assessment Schedule (WHODAS 2.0) as a basis for establishing specific criteria for evaluating relevant international scientific literature. The aims were to establish the extent of international dissemination and use of WHODAS 2.0 and analyze psychometric research on its various translations and adaptations. In particular, we wanted to highlight which psychometric features have been investigated, focusing on the factor structure, reliability, and validity of this instrument.

METHOD

Following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) methodology, we conducted a search for publications focused on "whodas" using the ProQuest, PubMed, and Google Scholar electronic databases.

RESULTS

We identified 810 studies from 94 countries published between 1999 and 2015. WHODAS 2.0 has been translated into 47 languages and dialects and used in 27 areas of research (40% in psychiatry).

CONCLUSIONS

The growing number of studies indicates increasing interest in the WHODAS 2.0 for assessing individual functioning and disability in different settings and individual health conditions. The WHODAS 2.0 shows strong correlations with several other measures of activity limitations; probably due to the fact that it shares the same disability latent variable with them. Implications for Rehabilitation WHODAS 2.0 seems to be a valid, reliable self-report instrument for the assessment of disability. The increasing interest in use of the WHODAS 2.0 extends to rehabilitation and life sciences rather than being limited to psychiatry. WHODAS 2.0 is suitable for assessing health status and disability in a variety of settings and populations. A critical issue for rehabilitation is that a single "minimal clinically important .difference" score for the WHODAS 2.0 has not yet been established.

Disability in bipolar I disorder: the 36-item World Health Organization Disability Assessment Schedule 2.0

BACKGROUND

The WHODAS 2.0 is an ICF-based multidimensional instrument developed for measuring disability. The present study analyzes the utility of the 36-item interviewer-administered version in a sample of patients with bipolar disorder. There is no study to date that analyses how the scale works in a sample that only comprises such patients.

METHODS

A total of 291 patients with bipolar disorder (42.6% males) according to DSM-IV-TR criteria from a cross-sectional study conducted in outpatient psychiatric clinics were enrolled. In addition to the WHODAS 2.0, patients completed a comprehensive assessment battery including measures on psychopathology, functionality and quality of life. Analyses were centered on providing evidence on the validity and utility of the Spanish version of the WHODAS 2.0 in bipolar patients.

RESULTS

Participation domain had the highest percentage of missing data (2.7%). Confirmatory factorial analysis was used to test three models formulated in the literature: six primary correlated factors, six primary factors with a single second-order factor, and six primary factors with two second-order factors. The three models were plausible, although the one formed by six correlated factors produced the best fit. Cronbach's alpha values ranged between .73 for the Self-care domain and .92 for Life activities, and the internal consistency of the total score was .96. Relationships between the WHODAS 2.0 and measures of psychopathology, functionality and quality of life were in the expected direction, and the scale was found to be able to differentiate among patients with different intensity of clinical symptoms and work situation.

LIMITATIONS

The percentage of euthymic patients was considerable. However, the assessment of euthymic patients is less influenced by mood. Some psychometric properties have not been studied, such as score stability and sensitivity to change.

CONCLUSIONS

The Spanish version of the 36-item WHODAS 2.0 has suitable psychometric properties in terms of reliability and validity when applied to patients with bipolar disorder. Disability in bipolar patients is especially prominent in Cognition, Getting along, Life activities, and Participation domains, so functional remediation interventions should emphasize these areas in order to improve the daily living activities of these patients.

Spanish cross-cultural adaptation and psychometric properties of the Schizophrenia Quality of Life short-version questionnaire (SQoL18) in 3 middle-income countries: Bolivia, Chile and Peru

OBJECTIVE

The aim of this study was to adapt the Schizophrenia - Quality of Life short-version questionnaire (SQoL18) for use in three middle-income countries in Latin America and to evaluate the factor structure, reliability, and external validity of this questionnaire.

METHODS

The SQoL18 was translated into Spanish using a well-validated forward-backward process. We evaluated the psychometric properties of the SQoL18 in a sample of 253 patients with schizophrenia attending outpatient mental health services in three Latin American countries. For participants in each country (Bolivia, N=83; Chile, N=85; Peru, N=85), psychometric properties were compared to those reported from the reference population (507 patients with schizophrenia) assessed in the validation study. In addition, differential item functioning (DIF) analyses were performed to see whether all items behave in the same way in each country.

RESULTS

Factor analysis performed in the 3 countries showed that the questionnaire's structure adequately matched the initial structure of the SQoL18. The unidimensionality of the dimensions was preserved, and the internal/external validity indices were close to those of the reference population. However, one dimension of the SQoL18 (resilience) presented some unsatisfactory properties including low Cronbach's alpha coefficients, one INFIT value higher than 1.2, and one item showing DIF between the 3 countries.

CONCLUSIONS

These results demonstrate the satisfactory acceptability and psychometric properties of the SQoL18, suggesting the relevance of this questionnaire among patients with schizophrenia in these 3 Latin American countries.

The cultural adaptability of intermediate measures of functional outcome in schizophrenia

The Measurement and Treatment Research to Improve Cognition in Schizophrenia initiative was designed to encourage the development of cognitive enhancing agents for schizophrenia. For a medication to receive this indication, regulatory agencies require evidence of improvement in both cognition and functional outcome. Because medication trials are conducted across multiple countries, we examined ratings of the cross-cultural adaptability of 4 intermediate measures of functional outcome (Independent Living Scales, UCSD Performance-based Skills Assessment, Test of Adaptive Behavior in Schizophrenia, Cognitive Assessment Interview [CAI]) made by experienced clinical researchers at 31 sites in 8 countries. English-speaking research staff familiar with conducting medication trials rated the extent to which each subscale of each intermediate measure could be applied to their culture and to subgroups within their culture based on gender, geographic region, ethnicity, and socioeconomic status on the Cultural Adaptation Rating Scale. Ratings suggested that the CAI would be easiest to adapt across cultures. However, in a recent study, the CAI was found to have weaker psychometric properties than some of the other measures. Problems were identified for specific subscales on all the performance-based assessments across multiple countries. India, China, and Mexico presented the greatest challenges in adaptation. For international clinical trials, it would be important to use the measures that are most adaptable, to adapt subscales that are problematic for specific countries or regions, or to develop a battery composed of the subscales from different instruments that may be most acceptable across multiple cultures with minimal adaptation.

The 12-item World Health Organization Disability Assessment Schedule II (WHO-DAS II): a nonparametric item response analysis

BACKGROUND

Previous studies have analyzed the psychometric properties of the World Health Organization Disability Assessment Schedule II (WHO-DAS II) using classical omnibus measures of scale quality. These analyses are sample dependent and do not model item responses as a function of the underlying trait level. The main objective of this study was to examine the effectiveness of the WHO-DAS II items and their options in discriminating between changes in the underlying disability level by means of item response analyses. We also explored differential item functioning (DIF) in men and women.

METHODS

The participants were 3615 adult general practice patients from 17 regions of Spain, with a first diagnosed major depressive episode. The 12-item WHO-DAS II was administered by the general practitioners during the consultation. We used a non-parametric item response method (Kernel-Smoothing) implemented with the TestGraf software to examine the effectiveness of each item (item characteristic curves) and their options (option characteristic curves) in discriminating between changes in the underliying disability level. We examined composite DIF to know whether women had a higher probability than men of endorsing each item.

RESULTS

Item response analyses indicated that the twelve items forming the WHO-DAS II perform very well. All items were determined to provide good discrimination across varying standardized levels of the trait. The items also had option characteristic curves that showed good discrimination, given that each increasing option became more likely than the previous as a function of increasing trait level. No gender-related DIF was found on any of the items.

CONCLUSIONS

All WHO-DAS II items were very good at assessing overall disability. Our results supported the appropriateness of the weights assigned to response option categories and showed an absence of gender differences in item functioning.

Measuring disability across cultures--the psychometric properties of the WHODAS II in older people from seven low- and middle-income countries. The 10/66 Dementia Research Group population-based survey

We evaluated the psychometric properties of the 12-item interviewer-administered screener version of the World Health Organization Disability Assessment Schedule-version II (WHODAS II) among older people living in seven low- and middle-income countries. Principal component analysis (PCA), confirmatory factor analysis (CFA) and Mokken analyses were carried out to test for unidimensionality, hierarchical structure, and measurement invariance across 10/66 Dementia Research Group sites. PCA generated a one-factor solution in most sites. In CFA, the two-factor solution generated in Dominican Republic fitted better for all sites other than rural China. The two factors were not easily interpretable, and may have been an artefact of differing item difficulties. Strong internal consistency and high factor loadings for the one-factor solution supported unidimensionality. Furthermore, the WHODAS II was found to be a 'strong' Mokken scale. Measurement invariance was supported by the similarity of factor loadings across sites, and by the high between-site correlations in item difficulties. The Mokken results strongly support that the WHODAS II 12-item screener is a unidimensional and hierarchical scale confirming to item response theory (IRT) principles, at least at the monotone homogeneity model level. More work is needed to assess the generalizability of our findings to different populations.

Contribution of chronic diseases to disability in elderly people in countries with low and middle incomes: a 10/66 Dementia Research Group population-based survey

BACKGROUND

Disability in elderly people in countries with low and middle incomes is little studied; according to Global Burden of Disease estimates, visual impairment is the leading contributor to years lived with disability in this population. We aimed to assess the contribution of physical, mental, and cognitive chronic diseases to disability, and the extent to which sociodemographic and health characteristics account for geographical variation in disability.

METHODS

We undertook cross-sectional surveys of residents aged older than 65 years (n=15 022) in 11 sites in seven countries with low and middle incomes (China, India, Cuba, Dominican Republic, Venezuela, Mexico, and Peru). Disability was assessed with the 12-item WHO disability assessment schedule 2.0. Dementia, depression, hypertension, and chronic obstructive pulmonary disease were ascertained by clinical assessment; diabetes, stroke, and heart disease by self-reported diagnosis; and sensory, gastrointestinal, skin, limb, and arthritic disorders by self-reported impairment. Independent contributions to disability scores were assessed by zero-inflated negative binomial regression and Poisson regression to generate population-attributable prevalence fractions (PAPF).

FINDINGS

In regions other than rural India and Venezuela, dementia made the largest contribution to disability (median PAPF 25.1% [IQR 19.2-43.6]). Other substantial contributors were stroke (11.4% [1.8-21.4]), limb impairment (10.5% [5.7-33.8]), arthritis (9.9% [3.2-34.8]), depression (8.3% [0.5-23.0]), eyesight problems (6.8% [1.7-17.6]), and gastrointestinal impairments (6.5% [0.3-23.1]). Associations with chronic diseases accounted for around two-thirds of prevalent disability. When zero inflation was taken into account, between-site differences in disability scores were largely attributable to compositional differences in health and sociodemographic characteristics.

INTERPRETATION

On the basis of empirical research, dementia, not blindness, is overwhelmingly the most important independent contributor to disability for elderly people in countries with low and middle incomes. Chronic diseases of the brain and mind deserve increased prioritisation. Besides disability, they lead to dependency and present stressful, complex, long-term challenges to carers. Societal costs are enormous.

FUNDING

Wellcome Trust; WHO; US Alzheimer's Association; Fondo Nacional de Ciencia Y Tecnologia, Consejo de Desarrollo Cientifico Y Humanistico, Universidad Central de Venezuela.

Psychometric properties of the Spanish BASIS-24 mental health survey

To assess mental health status among Latinos, culturally and linguistically appropriate instruments are needed. The purpose of this study was to assess psychometric properties and sensitivity of the Spanish revised Behavior and Symptom Identification Scale (BASIS-24), a self-report mental health assessment instrument first developed and validated in English. The Spanish translation was field tested among Spanish-speaking recipients of inpatient (N = 283) or outpatient (N = 311) mental health services in Massachusetts, Puerto Rico, and California. BASIS-24 was completed within 72 h of admission and up to 48 h before discharge (for inpatients) or at intake and 30-60 days later for outpatients. Confirmatory factor analysis indicated adequate fit for the model obtained from the English instrument. Internal consistency reliability exceeded 0.70 for five of the six factors. Concurrent and discriminant validity were partially supported. Improvement following treatment was statistically significant, with small to moderate effect sizes.

Psychometric properties of the WHODASII in rehabilitation patients

BACKGROUND

To evaluate function and disability, the WHO has developed the WHO Disability Assessment Schedule II (WHODASII), an instrument arising from the same conceptual basis as the International Classification of Functioning, Disability, and Health (ICF).

OBJECTIVES

The general objective of this study was to investigate whether the WHODASII--German version-is a valid instrument to measure functioning and disability across various conditions. Specific aims were (1) to assess its psychometric properties (reliability, validity, and sensitivity to change) based on the traditional test theory and (2) to compare its sensitivity to change after a rehabilitative intervention to the Short Form 36 (SF-36).

RESEARCH DESIGN

This was a multi-center study with convenience samples of patients with different chronic conditions undergoing rehabilitation. Patients completed the WHODASII and the SF-36 before and after a rehabilitation treatment. Health professionals rated in cooperation with the patients the pain of the patients based on the ICF category "sensation of pain."

RESULTS

904 patients were included in the study. The Cronbach's range from 0.70 to 0.97 for the different subscales of WHODASII. With exception of the subscale Activities, the exploratory-factor structure of the WHODASII corresponds highly with the original structure. The effect size (ES) of the WHODASII total score ranged from 0.16 to 0.69 depending on the subgroup. The ES of the SF-36 summary scores ranged from 0.03 to 1.40.

CONCLUSIONS

The WHODAS II (German version) is a useful instrument for measuring functioning and disability in patients with musculoskeletal diseases, internal diseases, stroke, breast cancer, and depressive disorder. The results of this study support the reliability, validity, dimensionality, and responsiveness of the German version of the WHODASII. However, the reproducibility in test-retest samples of stable patients, as well as the question to what extent a summary score can be constructed, requires further investigation.