Systematic review of the measurement properties of the Depression Anxiety Stress Scales-21 by applying updated COSMIN methodology.

PURPOSE: The Depression Anxiety Stress Scales (DASS)-21 measures emotional symptoms of depression, anxiety, and stress, is relatively short, and is freely available in the public domain, which has resulted in it being applied to various clinical and non-clinical populations in many countries. The aim of this study was to systematically review the measurement properties of the DASS-21. METHODS: The MEDLINE, Embase, and CINAHL databases were searched. The methodological quality of each identified study was assessed using the updated COSMIN Risk of Bias checklist. The quality of the measurement properties of the studies was rated using the updated criteria for good measurement properties. The quality of evidence was rated using a modified version of the GRADE approach. RESULTS: This study included 48 studies in its review. The content validity of the DASS-21 demonstrated sufficient moderate-quality evidence. The instrument exhibited sufficient high-quality evidence for bifactor structural validity and internal consistency. The instrument also showed sufficient high-quality evidence for hypothesis testing of construct validity. Regarding criterion validity, only the DASS-21 Depression subscale demonstrated sufficient high-quality evidence. The measurement invariance across gender demonstrated inconsistent moderate-quality evidence. There was insufficient low-quality evidence for the reliability of each subscale. For responsiveness there was sufficient low-quality evidence for depression and stress subscales, and insufficient very-low-quality evidence for anxiety subscale. CONCLUSIONS: The DASS-21 demonstrated sufficient high-quality evidence for bifactor structural validity, internal consistency (bifactor), criterion validity (Depression subscale), and hypothesis testing for construct validity. Further studies are required to assess the other measurement properties of the DASS-21.

The 21-Item and 12-Item Versions of the Depression Anxiety Stress Scales: Psychometric Evaluation in a Korean Population.

PURPOSE: This study aimed to evaluate the psychometric properties of the Depression Anxiety Stress Scales 21 and 12 in a Korean population. METHODS: The Depression Anxiety Stress Scales were translated into Korean using a translation and back-translation technique, and the content validity was assessed by an expert panel. Participants were recruited from six community health centers (n = 431) and two community mental health centers (n = 50). A field test of the psychometric properties of the instruments was conducted using confirmatory factor analysis with bootstrap maximum likelihood estimation involving 1,000 samples, Pearson's analysis, t test, and Cronbach's α coefficient. RESULTS: Confirmatory factor analysis of the Depression Anxiety Stress Scales 21 and 12 supported both three-factor and second-order three-factor models. The Scales 21 and 12 satisfied convergent validity with the Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, and Perceived Stress Scale-10 and discriminant validity with the Rosenberg Self-Esteem Scale. The scores for the Depression Anxiety Stress Scales 21 and 12 were higher for the psychiatric group than for the nonpsychiatric group, confirming the presence of known-groups validity. The Depression Anxiety Stress Scales 21 and 12 exhibited moderate-to-strong correlations with the Negative Affect. Cronbach's α coefficients for the Depression Anxiety Stress Scales 21 and 12 were .93 and .90, respectively. CONCLUSION: The Depression Anxiety Stress Scales 21 and 12 appear to be acceptable, reliable, and valid instruments. However, the shorter Depression Anxiety Stress Scales 12 may be more feasible to use in a busy practice and also be less burdensome to respondents.

Self-administered health literacy instruments for people with diabetes: systematic review of measurement properties.

AIMS: The aims of this study were to identify all available self-administered instruments measuring health literacy in people with diabetes and to determine the current instrument that is the most appropriate for applying to this population in both practice and research. DESIGN: A systematic review of measurement properties. DATA SOURCES: MEDLINE, EMBASE and CINAHL electronic databases from their inception up to 28 March 2016. REVIEW METHOD: The methodological quality of each included study was assessed using the COnsensus-based Standards for the selection of health Measurement INstruments checklist. The reported results for measurement properties in the studies were assessed according to Terwee's quality criteria. RESULTS: Thirteen self-administered instruments measuring health literacy in people with diabetes were identified, of which six (44%) were diabetes-specific instruments. The instruments that covered the broadest contents of health literacy were the Health Literacy Scale and Health Literacy Questionnaire. The (test-retest) reliability, measurement error and responsiveness were not evaluated for any instrument, while internal consistency and hypothesis testing validity were the most frequently assessed measurement properties. CONCLUSIONS: With the current evidence, the Health Literacy Scale may be the most appropriate instrument for patients with diabetes in practice and research. However, the structural validity of this scale needs to be further established, particularly in other language versions. It is also recommended to use the Diabetes Numeracy Test-15 along with the Health Literacy Scale to complement the lack of numeracy measures in the Health Literacy Scale.

A systematic review of measurement properties of the instruments measuring health-related quality of life in patients with irritable bowel syndrome.

PURPOSE: The systematic review of patient-reported outcome instruments can allow the selection of the most appropriate instrument for use in research and clinical practice. There has been no systematic review of the measurement properties of irritable bowel syndrome (IBS)-specific health-related quality-of-life (HRQOL) instruments. The purposes of this study were to identify all available instruments for measuring the IBS-specific HRQOL and to determine which is the most appropriate instrument to apply in clinical practice. METHODS: A systematic review study was conducted. The MEDLINE, EMBASE, and CINAHL databases were searched. The methodological quality of the included studies was assessed using the COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments) checklist. The measurement property results of each study were assessed using Terwee's quality criteria. RESULTS: Seven instruments were identified: The Irritable Bowel Syndrome-Quality of Life (IBS-QOL) instrument was the only one that had been analyzed in multiple studies, with each of the remaining six instruments only being analyzed in a single psychometric study. The IBS-QOL demonstrated moderate positive evidence for internal consistency and reliability and is the best instrument based on the currently available evidence. CONCLUSIONS: Even though the IBS-QOL is currently the best instrument, there is conflicting evidence for its underlying structural validity. The factor structure or dimensionality of the IBS-QOL needs to be elucidated further.

A Structural Equation Model Linking Health Literacy to Self-efficacy, Self-care Activities, and Health-related Quality of Life in Patients with Type 2 Diabetes.

PURPOSE: Health literacy has been attracting increasing attention because low health literacy is considered an important predictor of adverse health outcomes in many chronic conditions, including diabetes. However, it is unclear how health literacy is associated with health outcomes. The purpose of this study was to formulate a hypothetical structural equation model linking health literacy to self-efficacy, self-care activities, and health-related quality of life (HRQOL) in patients with type 2 diabetes. METHODS: A cross-sectional survey design was employed, and 459 patients with type 2 diabetes were recruited from outpatient clinics in two university hospitals. The patients completed a pack of questionnaires. The hypothetical model was tested using structural equation modeling analysis. RESULTS: The values of multiple fit indices indicated that the proposed model provided a good fit to the data. Health literacy exerted not only a direct effect on self-care activities, but also an indirect effect on self-care activities via self-efficacy. However, health literacy exerted only an indirect effect on HRQOL. This structural model was invariant across hemoglobin-A1c-controlled and hemoglobin-A1c-uncontrolled groups. Based on R(2) values, the final model accounted for 20.0% of the variance in self-efficacy, 61.0% of the variance in self-care activities, and 16.0% of the variance in HRQOL. CONCLUSIONS: This study suggests that self-care activities are crucial to the link between health literacy and HRQOL. Both health literacy and self-efficacy need to be considered in clinical practice for enhancing self-care activities in patients with type 2 diabetes. This approach may ultimately improve HRQOL in these patients.

Diabetes-related emotional distress instruments: a systematic review of measurement properties.

OBJECTIVES: The objectives of this study were to identify all available diabetes-related emotional distress instruments and evaluate the evidence regarding their measurement properties to help in the selection of the most appropriate instrument for use in practice and research. DESIGN: A systematic literature search was performed. DATA SOURCES: PubMed, Embase, CINAHL, and PsycINFO were searched systematically for articles on diabetes-related emotional distress instruments. REVIEW METHODS: The Consensus-based Standards for the Selection of Health Measurement Instruments checklist was used to evaluate the methodological quality of the identified studies. The quality of results with respect to the measurement properties of each study was evaluated using Terwee's quality criteria. An ancillary meta-analysis was performed. RESULTS: Of the 2345 articles yielded by the search, 19 full-text articles evaluating 6 diabetes-related emotional distress instruments were included in this study. No instrument demonstrated evidence for all measurement properties. The Problem Areas in Diabetes scale (PAID) was the most frequently studied and the best validated of the instruments. Pooled summary estimates of the correlation coefficient between the PAID and serum glycated hemoglobin revealed a positive but weak correlation. CONCLUSIONS: No diabetes-related emotional distress instrument demonstrated evidence for all measurement properties. No instrument was better than another, although the PAID was the best validated and is thus recommended for use. Further psychometric studies of the diabetes-related emotional distress instruments with rigorous methodologies are required.

Psychometric Properties of the Diabetes Management Self-Efficacy Scale in Korean Patients with Type 2 Diabetes.

Objectives. The aims of this study were to perform a cultural translation of the DMSES and evaluate the psychometric properties of the translated scale in a Korean population with type 2 diabetics. Methods. This study was conducted in patients with diabetes recruited from university hospitals. The first stage of this study involved translating the DMSES into Korean using a forward- and backward-translation technique. The content validity was assessed by an expert group. In the second stage, the psychometric properties of the Korean version of the DMSES (K-DMSES) were evaluated. Results. The content validity of the K-DMSES was satisfactory. Sixteen-items clustered into four-subscales were extracted by exploratory factor analysis, and supported by confirmatory factor analysis. The construct validity of the K-DMSES with the Summary of Diabetes Self-Care Activities scale was satisfactory (r = 0.50, P<0.001). The Cronbach's alpha and intraclass correlation coefficient were 0.92 and 0.85 (P<0.001; 95% CI = 0.75-0.91), respectively, which indicate excellent internal consistency reliability and test-retest reliability. Conclusions. The K-DMSES is a brief instrument that has demonstrated good psychometric properties. It is therefore feasible to use in practice, and is ready for use in clinical research involving Korean patients with type 2 diabetes.

Psychometric evaluation of the Korean version of the Diabetes Symptom Checklist-Revised (DSC-R) for patients with type 2 diabetes.

BACKGROUND: This study was to elucidate the psychometric properties of the Korean version of the Diabetes Symptom Checklist-Revised (K-DSC-R), which is a patient-reported outcome measure of diabetes symptom burden. METHODS: A sample of 432 Korean patients with diabetes was recruited from university hospitals. The data were analyzed using exploratory factor analysis (EFA), confirmatory factor analysis (CFA), multitrait/multi-item correlation, Pearson's correlation, t-test, ANOVA, and Cronbach's alpha for construct, item-convergent/discriminant, concurrent, and known-groups validity, and internal consistency reliability. RESULTS: EFA extracted a total of 29 items clustered into 7 subscales from the K-DSC-R. The construct of the seven-subscales was supported by CFA. The scaling success rates of item-convergent validity were 100% for all subscales, and those of item-discriminant validity ranged from 83.3% to 100%. Patients in more-depressed groups and in the HbA1c-uncontrolled group had higher K-DSC-R scores, satisfying the known-groups validity. The subscales of the K-DSC-R were moderately correlated with health-related quality of life, indicative of the established concurrent validity. The Cronbach's alpha of the K-DSC-R was 0.92. CONCLUSIONS: The psychometric properties of the K-DSC-R have been established. It is thus appropriate for use with respect to reliability and validity in practice and clinical trials for Korean patients with type 2 diabetes.

Measurement properties of rheumatoid arthritis-specific quality-of-life questionnaires: systematic review of the literature.

PURPOSE: This study conducted a systematic review of the methodological quality of the psychometric evaluation process and the quality of measurement properties of rheumatoid arthritis (RA)-specific health-related quality-of-life (HRQOL) questionnaires with the purpose of obtaining the best evidence to help in the selection of the most appropriate instrument for measuring HRQOL in RA patients. METHODS: A systematic literature search was performed to identify RA-specific HRQOL questionnaires in databases. The methodological quality of the studies was assessed using the Consensus-based Standards for the Selection of Health Measurement Instruments checklist. The quality of the measurement properties was assessed using quality criteria. The evidence regarding the measurement properties was pooled using best-evidence synthesis, with considerations of the number and methodological quality of the studies, and the consistency of their findings in terms of the quality of the measurement properties. RESULTS: The search identified 37 studies describing 9 instruments. Best-evidence synthesis suggested that the Rheumatoid Arthritis Quality of Life (RAQoL) questionnaire had the strongest positive evidence, especially with respect to reliability, measurement error, and content validity, and moderate positive evidence with respect to hypothesis testing and responsiveness. CONCLUSIONS: The current evidence suggests that the best-validated instrument among the RA-specific HRQOL measures is the RAQoL questionnaire in terms of both methodological quality in the process of psychometric evaluation and the quality of the measurement properties. However, there is limited evidence regarding internal consistency and structural validity of the RAQoL. Further efforts are warranted to establish the psychometric quality of this questionnaire.