Cross-cultural Measurement Equivalence of the KINDL Questionnaire for Quality of Life Assessment in Children and Adolescents

A Machine Learning Approach to Assess Differential Item Functioning of the KINDL Quality of Life Questionnaire Across Children with and Without ADHD

This study aimed to investigate differential item functioning (DIF) of the child and parent reports of the KINDL measure across children with and without Attention-deficit/hyperactivity disorder (ADHD). The sample included 122 children with ADHD and 1086 healthy peers, alongside 127 and 1061 of their parents, respectively. The generalized partial credit model with lasso penalization, as a machine learning method, was used to assess DIF of the KINDL across the two groups. The findings showed that three out of 24 items of the child reports and seven out of 24 items of the parent reports of the KINDL exhibited DIF between children with and without ADHD. Accordingly, Iranian children with and without ADHD along with their parents perceive almost all items in the KINDL similarly. Hence, the observed difference in quality of life scores between children with and without ADHD is a real difference and not a reflection of measurement bias.

Cross-cultural measurement invariance of the Quality of Life Enjoyment and Satisfaction Questionnaire-Short form across ten countries: the application of Bayesian approximate measurement invariance

Background

The Quality of Life Enjoyment and Satisfaction Questionnaire-Short Form (Q-LES-Q-SF) is the most frequently used generic quality of life (QOL) measure in many countries and cultures worldwide. However, no single study has been carried out to investigate whether this questionnaire performs similarly across diverse cultures/countries. Accordingly, this study aimed to assess the cross-cultural measurement invariance of the Q-LES-Q-SF across ten different countries.

Methods

The Q-LES-Q-SF was administrated to a sample of 2822 university students from ten countries: Bangladesh, Brazil, Croatia, India, Nepal, Poland, Serbia, Turkey, the United Arab Emirates, and Vietnam. The Bayesian approximate measurement invariance approach was used to assess the measurement invariance of the Q-LES-Q-SF.

Results

Approximate measurement invariance did not hold across the countries for the Q-LES-Q-SF, with only two out of 14 items being non-invariant; namely items related to doing household and leisure time activities.

Conclusions

Our findings did not support the cross-cultural measurement invariance of the Q-LES-Q-SF; thus, considerable caution is warranted when comparing QOL scores across different countries with this measure. Item rewording and adaptation along with calibrating non-invariant items may narrow these differences and help researchers to create an invariant questionnaire for reliable and valid QOL comparisons across different countries.

A Comparative Study of the Bias Correction Methods for Differential Item Functioning Analysis in Logistic Regression with Rare Events Data

The logistic regression (LR) model for assessing differential item functioning (DIF) is highly dependent on the asymptotic sampling distributions. However, for rare events data, the maximum likelihood estimation method may be biased and the asymptotic distributions may not be reliable. In this study, the performance of the regular maximum likelihood (ML) estimation is compared with two bias correction methods including weighted logistic regression (WLR) and Firth's penalized maximum likelihood (PML) to assess DIF for imbalanced or rare events data. The power and type I error rate of the LR model for detecting DIF were investigated under different combinations of sample size, moderate and severe magnitudes of uniform DIF (DIF = 0.4 and 0.8), sample size ratio, number of items, and the imbalanced degree (τ). Indeed, as compared with WLR and for severe imbalanced degree (τ = 0.069), there were reductions of approximately 30% and 24% under DIF = 0.4 and 27% and 23% under DIF = 0.8 in the power of the PML and ML, respectively. The present study revealed that the WLR outperforms both the ML and PML estimation methods when logistic regression is used to evaluate DIF for imbalanced or rare events data.

The adaptation process and preliminary psychometric evaluation of the Polish version of Kiddo-KINDL questionnaire

The assessment of health-related quality of life (HRQoL) is increasingly important in fields of public health, medicine, sociology and psychology. The aim of the study was to evaluate the psychometric properties of the Polish version of generic Kiddo-KINDL questionnaire for adolescents. The psychometric evaluation was performed using 96 questionnaires fulfilled by adolescents aged 12–16 years. Cronbach’s α coefficient for internal consistency and split-half reliability was estimated as well as ceiling, floor effect and correlations among the subscales and total score. The mean reliability for subscales was 0.65 and the Cronbach’s α coefficient for the total score was 0.85. The lowest α coefficient was for the School dimension (0.44) and the highest was achieved for the Self-esteem (0.80). The correlation between two parts of the questionnaire and split-half reliability was 0.66 and 0.80 respectively. The first psychometric evaluation of the Polish Kiddo-KINDL showed promising basic measurement properties, but it needs farther assessment, including convergent, construct and discriminant validity estimation.

Measurement invariance of the Depression Anxiety Stress Scales-21 across medical student genders

OBJECTIVES

This study aimed to assess whether male and female Iranian medical students perceived the meaning of the items in the Depression Anxiety Stress Scales-21 consistently.

METHODS

A convenience sample of 783 preclinical medical students from the first to sixth semester was invited to this cross-sectional study. Of the 477 respondents, 238 were male and 239 were female. All participants completed the Persian version of the Depression Anxiety Stress Scales-21. The graded response model was used to assess measurement invariance of the instrument across the gender groups. Categorical confirmatory factor analysis was used to evaluate the construct validity of the measure. Moreover, internal consistency was assessed via Cronbach's Alpha.

RESULTS

Statistically significant differential item functioning was flagged for just item 6 in the depression subscales (c²=6.5, df=1, p=0.011). However, removing or retaining the item 6 in the stress subscale did not change our findings significantly, when we compared stress scores across two genders. The results of categorical confirmatory factor analysis supported the fit of the three-factor model of Depression Anxiety Stress Scales-21. Moreover, Cronbach's alpha was greater than 0.7 in depression, anxiety and stress subscales.

CONCLUSIONS

This study revealed that Depression Anxiety Stress Scales-21 is an invariant measure across male and female medical students. Hence, this reliable and valid instrument can be used for meaningful comparison of distress scores between medical student genders. Gender comparisons of medical students' psychological profiles provide a better insight into gender influences on the outcome of medical education and medical practice.

Psychometric evaluation and wording effects on the Chinese version of the parent-proxy Kid-KINDL

Background

The pediatric quality of life (QoL) questionnaire, the child-rated Kid-KINDL, has wording effects. However, no studies have examined for its parallel questionnaire, the parent-proxy Kid-KINDL. This study aimed to examine the psychometric properties and wording effects of the parent-proxy Kid-KINDL.

Methods

Parents with 8- to 12-year-old children (n = 247) completed the parent-proxy Kid-KINDL, 83 of them completed it again 7–14 days later, and 241 of their children completed the child-rated Kid-KINDL. Internal consistency was examined using Cronbach’s α; test-retest reliability and concurrent validity, using Pearson correlation coefficients (r); construct validity and wording effects, using confirmatory factor analyses (CFAs).

Results

The internal consistency of the parent-proxy Kid-KINDL total score was acceptable (α = .86). Test-retest reliability (r = .33–.60) and concurrent validity (r = .27–.42) were acceptable or nearly acceptable for all subscales and the total score. The CFA models simultaneously accounting for QoL traits and wording effects had satisfactory fit indices, and outperformed the model accounting only for QoL traits. However, four subscales had unsatisfactory internal consistency, which might be attributable to wording effects.

Conclusion

When children are unable to complete a QoL questionnaire, the parent-proxy Kid-KINDL can substitute with all due cautions to wording effects and inconsistent reliability among different raters.

Testing measurement equivalence of the SF-36 questionnaire across patients on hemodialysis and healthy people

BACKGROUND

Differential item functioning (DIF) occurs when members from different groups respond differently to particular items in a health-related quality of life (HRQoL) questionnaire after controlling for underlying HRQoL construct. This study aimed to assess DIF in the SF-36 questionnaire and its effect on comparing HRQoL scores across patients on HD and healthy people.

METHODS

One hundred fifty patients on maintenance hemodialysis (HD) and 642 healthy individuals filled out the Persian version of the SF-36 questionnaire. Multiple-group multiple-indicator multiple-causes (MG-MIMIC) model was used to assess DIF across patients on HD and healthy population.

RESULTS

Sixteen out of 36 (44.4 %) items were flagged with DIF. Six out of 16 items (37.5 %) were flagged with uniform DIF, nine items (56.2 %) with non-uniform DIF, and one item (6.2 %) with both uniform DIF and non-uniform DIF. DIF items were associated with all subscales with the exception of the limitation due to physical problems and bodily pain subscales. The significant lower HRQoL scores of patients on HD in comparison with healthy people in the physical functioning and vitality subscales did not change after removing the items with uniform DIF.

CONCLUSIONS

Our findings revealed that patients on HD and healthy people perceived the meaning of the items in SF-36 questionnaire differently. Although the impact of DIF is minimal, the cross-group comparison across patients on HD and healthy people should be performed with caution.