Mokken scaling of the Myocardial Infarction Dimensional Assessment Scale (MIDAS)

Development and Validation of the Coronary Heart Disease Scale Among the System of Quality of Life Instruments for Chronic Diseases QLICD-CHD (V2.0) Based on Classical Test Theory and Generalizability Theory

Objective

Coronary heart disease (CHD) is a common and frequent disease with a long and incurable course, and the quality of life of patients is severely reduced. This study was to develop and validate a quality of life scale for patients with CHD based on the Chinese context.

Methods

The scale QLICD-CHD (V2.0) was developed based on the QLICD-CHD (V1.0), using a programmed decision procedures. Based on the data measuring QoL 3 times before and after treatments from 189 patients with CHD, the psychometric properties of the scale were evaluated with respect to validity, reliability and responsiveness employing correlation analysis, multi-trait scaling analysis, structural equation modeling, t-test and also G-study and D-study of generalizability theory analysis. The SF-36 scale was used as the criterion to evaluate the criterion-related validity. Paired t tests were conducted to evaluate the responsiveness on each domain/facet as well as the total of the scale, with Standardized Response Mean (SRM) being calculated.

Results

The QLICD-CHD (V2.0) has been developed with 42 items in 4 domains. The Cronbach's α of the general module, the specific module and the total scale were 0.91, 0.92 and 0.91 respectively. The overall score and the test-retest reliability coefficients in all domains are higher than 0.60, except for the specific module. Correlation and factor analysis confirmed good construct validity and criterion-related validity. After treatments, the overall score and score of all domains have statistically significant changes (P<0.01). The SRM of domain-level score ranges from 0.27 to 0.50. Generalizability Theory further confirm the reliability of the scale through more accurate variance component studies.

Conclusion

The QLICD-CHD (V2.0) could be used as a useful instrument in assessing QoL for patients with CHD, with good psychometric properties.

Effects of quercetin supplementation on inflammatory factors and quality of life in post-myocardial infarction patients: A double blind, placebo-controlled, randomized clinical trial

Myocardial infarction (MI) is one of the leading causes of death in the world. Epidemiological studies have shown that dietary flavonoids are inversely related to cardiovascular morbidity and mortality. The study aimed to determine whether quercetin supplementation can improve inflammatory factors, total antioxidant capacity (TAC) and quality of life (QOL) in patients following MI. This randomized double-blind, placebo-controlled trial was conducted on 88 post-MI patients. Participants were randomly assigned into quercetin (n = 44) and placebo groups (n = 44) receiving 500 mg/day quercetin or placebo tablets for 8 weeks. Quercetin supplementation significantly increased serum TAC compared to placebo (Difference: 0.24 (0.01) mmol/L and 0.00 (0.00) mmol/L respectively; p < .001). TNF-α levels significantly decreased in the quercetin group (p = .009); this was not, however, significant compared to the placebo group. As for QOL dimensions, quercetin significantly lowered the scores of insecurity (Difference: -0.66 (12.5) and 0.00 (5.55) respectively; p < .001). No significant changes in IL-6, hs-CRP, blood pressure and other QOL dimensions were observed between the two groups. Quercetin supplementation (500 mg/day) in post-MI patients for 8 weeks significantly elevated TAC and improved the insecurity dimension of QOL, but failed to show any significant effect on inflammatory factors, blood pressure and other QOL dimensions.

Adaptação transcultural do Myocardial Infarction Dimensional Assessment Scale (MIDAS) para a língua portuguesa brasileira

Resumo A partir da avaliação dos fatores que incidem na qualidade de vida (QV) é possível planejar as intervenções que proporcionam melhoria do bem-estar dos pacientes. Realizar a adaptação transcultural do questionário Miocardial Infarction Dimensional Assessment Scale (MIDAS) para língua portuguesa, buscando as equivalências semântica, idiomática, conceitual e cultural. Foi utilizado o referencial teórico de Guillemin, Bombardier e Beaton, cumprindo as seguintes etapas: tradução, retrotradução, avaliação dos autores, banca de juízes e pré-teste. Após todas as avaliações, foram alcançadas as equivalências semântica, conceitual, idiomática e cultural. A escala mostrou-se de fácil aplicação e importância clínica. O MIDAS encontra-se validado no que se refere às equivalências semânticas, idiomáticas, conceituais e culturais. Posteriormente, será avaliada a equivalência de mensuração, para verificar as propriedades psicométricas.

Scalability and internal consistency of the German version of the dementia-specific quality of life instrument QUALIDEM in nursing homes - a secondary data analysis

BACKGROUND

Quality of life (Qol) is a widely selected outcome in intervention studies. The QUALIDEM is a dementia-specific Qol-instrument from The Netherlands. The aim of this study is to evaluate the scalability and internal consistency of the German version of the QUALIDEM.

METHODS

This secondary data analysis is based on a total sample of 634 residents with dementia from 43 nursing homes. The QUALIDEM consists of nine subscales that were applied to a subsample of 378 people with mild to severe dementia and six consecutive subscales that were applied to a subsample of 256 people with very severe dementia. Scalability, internal consistency and distribution scores were calculated for each predefined subscale using the Mokken scale analysis.

RESULTS

In people with mild to severe dementia, seven subscales, care relationship, positive affect, negative affect, restless tense behavior, positive self-image, social relations and feeling at home, were scalable (0.31 ≤ H ≤ 0.65) and internally consistent (Rho ≥ 0.62). The subscales social isolation (H = 0.28) and having something to do (H = 0.18) were not scalable and exhibited insufficient reliability scores (Rho ≤ 0.53). For people with very severe dementia, five subscales, care relationship, positive affect, restless tense behavior, negative affect and social relations, were scalable (0.33 ≤ H ≤ 0.65), but only the first three of these subscales showed acceptable internal consistency (Rho 0.59 - 0.86). The subscale social isolation was not scalable (H = 0.20) and exhibited poor internal consistency (Rho = 0.42).

CONCLUSIONS

The results show an acceptable scalability and internal consistency for seven QUALIDEM subscales for people with mild to severe dementia and three subscales for people with very severe dementia. The subscales having something to do (mild to severe dementia), negative affect (very severe dementia), social relations (very severe dementia) and social isolation (both versions) produced unsatisfactory results and require revision.

The Chinese version of the cardiac depression scale: Mokken scaling

Background

Myocardial infarction is a major cause of death and morbidity in many countries, including China. The aim of this study was to analyse a Mandarin Chinese translation of the Cardiac Depression Scale for a hierarchy of items according to the criteria of Mokken scaling.

Findings

Data from 438 Chinese participants who completed the Chinese translation of the Cardiac Depression Scale were analysed using the Mokken scaling procedure and the 'R' statistical programme using the diagnostics available in these programmes. Correlations between Mandarin Chinese items and Chinese translations of the Hospital Anxiety and Depression Scale and the Beck Depression Inventory were also analysed. Fifteen items from the Mandarin Chinese Cardiac Depression Scale were retained in a weak but reliable Mokken scale; invariant item ordering was evident but of low accuracy and the Mokken scaled items of the Chinese Cardiac Depression Scale correlated with the Hospital Anxiety and Depression Scale and the Beck Depression Inventory.

Conclusions

Items from the Mandarin Chinese Cardiac Depression Scale form a Mokken scale and this offers further insight into how the items of the Cardiac Depression Scale relate to the measurement of depression in people with a myocardial infarction.

The Chinese version of the Myocardial Infarction Dimensional Assessment Scale (MIDAS): Mokken scaling

Background

Hierarchical scales are very useful in clinical practice due to their ability to discriminate precisely between individuals, and the original English version of the Myocardial Infarction Dimensional Assessment Scale has been shown to contain a hierarchy of items. The purpose of this study was to analyse a Mandarin Chinese translation of the Myocardial Infarction Dimensional Assessment Scale for a hierarchy of items according to the criteria of Mokken scaling. Data from 180 Chinese participants who completed the Chinese translation of the Myocardial Infarction Dimensional Assessment Scale were analysed using the Mokken Scaling Procedure and the 'R' statistical programme using the diagnostics available in these programmes. Correlation between Mandarin Chinese items and a Chinese translation of the Short Form (36) Health Survey was also analysed.

Findings

Fifteen items from the Mandarin Chinese Myocardial Infarction Dimensional Assessment Scale were retained in a strong and reliable Mokken scale; invariant item ordering was not evident and the Mokken scaled items of the Chinese Myocardial Infarction Dimensional Assessment Scale correlated with the Short Form (36) Health Survey.

Conclusions

Items from the Mandarin Chinese Myocardial Infarction Dimensional Assessment Scale form a Mokken scale and this offers further insight into how the items of the Myocardial Infarction Dimensional Assessment Scale relate to the measurement of health-related quality of life people with a myocardial infarction.

Item response theory: how Mokken scaling can be used in clinical practice

AIMS

To demonstrate the principles and application of Mokken scaling.

BACKGROUND

The history and development of Mokken scaling is described, some examples of applications are given, and some recent development of the method are summarised.

DESIGN

Secondary analysis of data obtained by cross-sectional survey methods, including self-report and observation.

METHODS

Data from the Edinburgh Feeding Evaluation in Dementia scale and the Townsend Functional Ability Scale were analysed using the Mokken scaling procedure within the 'R' statistical package. Specifically, invariant item ordering (the extent to which the order of the items in terms of difficulty was the same for all respondents whatever their total scale score) was studied.

RESULTS

The Edinburgh Feeding Evaluation in Dementia scale and the Townsend Functional Ability Scale showed no violations of invariant item ordering, although only the Townsend Functional Ability Scale showed a medium accuracy.

CONCLUSION

Mokken scaling is an established method for item response theory analysis with wide application in the social sciences. It provides psychometricians with an additional tool in the development of questionnaires and in the study of individuals and their responses to latent traits. Specifically, with regard to the analyses conducted in this study, the Edinburgh Feeding Evaluation in Dementia scale requires further development and study across different levels of severity of dementia and feeding difficulty.

RELEVANCE TO CLINICAL PRACTICE

Good scales are required for assessment in clinical practice and the present paper shows how a relatively recently developed method for analysing Mokken scales can contribute to this. The two scales used as examples for analysis are highly clinically relevant.