Development and validation of the revised Cedars-Sinai health-related quality of life for rheumatoid arthritis instrument

Development and validation of the rheumatoid arthritis scale among the system of quality of life instruments for chronic diseases QLICD-RA (V2.0)

Rheumatoid Arthritis is a more serious threatening to people and suitable for QOL measurement. A few specific QOL instruments are available without considering Chinese culture. The present study was aimed to develop and validate the Rheumatoid Arthritis Scale among the System of Quality of Life Instruments for Chronic Diseases (QLICD-RA V2.0). The data collected from 379 patients with RA was used to evaluate the psychometric properties of the scale. The reliability was evaluated by the internal consistency Cronbach's α, test-retest reliability Pearson correlation r and intra-class correlation (ICC). We evaluated the construct validity and criteria-related validity by correlation analysis and structural equation modeling. We compared the differences in scores of QLICD-RA before and after treatment and used the Standard Response Mean (SRM) to assess the responsiveness. The results showed that the internal consistency coefficient Cronbach's α values were greater than 0.70. The correlations r and ICCs were greater than 0.80. The correlation analysis and structural equation modeling confirmed good construct validity and criterion-related validity. The SRM ranges from 0.07 to 0.27 for significant domains/facets. It concluded that QLICD-RA (2.0) is a reliable and valid instrument to measure QOL among patients with RA.

Why Exercise at Work: Development of the Office Exercise Behavior Determinants Scale

The constant increase in work pressure and the penetration of labor-saving technologies have significantly reduced physical activity in office-based work routines, threatening employees’ physical and mental well-being. Encouraging physical exercises at the office seems a potential solution. However, while there is a wealth of research into occupational health and workplace exercise promotion, little is known about which factors can influence the engagement of physical exercises in the office context. It is crucial to understand these determinants, in order to support the design of office exercise promoting intervention. This study explored the determinants of office workers’ exercise behavior by proposing and developing the Office Exercise Behavior Determinants (OEBD) scale based on existing behavioral and environmental research. The OEBD scale was assessed through an online questionnaire study involving 479 office workers. The results indicated that four factors (Intrinsic Motivation, Extrinsic Motivation, Social Environment, and Work Environment) contribute to office workers’ exercise behavior. Furthermore, confirmatory factor analysis of our obtained data provided evidence for the internal validity of the OEBD scale. Thereby, this research can support increased office exercise with valid measurements for behavioral determinants.

Sensitivity and specificity of assessment instruments of quality of life in rheumatoid arthritis

OBJECTIVE

To check sensitivity and specificity of assessment instruments of QoL in patients with rheumatoid arthritis (RA).

METHODOLOGY

Accuracy study in a sample consisting of patients with confirmed diagnosis of RA. QoL questionnaires QV SF-36 (Gold Standard), HAQ and NHP were applied. The Pearson correlation coefficient, ROC curve, AUC and Youden Index (J) were used to analyze the data.

RESULTS

This study enrolled 97 individuals with RA. The functional capacity estimated by SF-36 was correlated with the total score of HAQ (r=-0.666; p<0.001; J=0.579), while the emotional aspects of SF-36 were correlated with the emotional reactions domain of NHP (r=-0.316; p=0.005; J=0.341). The vitality domain of SF-36 was correlated with the level of energy of NHP (r=-0.362; p=0.001; J=0.302). For the evaluation of functional capacity (AUC=0.839; p<0.001) and physical aspect (AUC=0.755; p<0.001) the most accurate instrument was the HAQ. For evaluation of the impact of vitality, sleep (AUC=0.679; p=0.007), emotional reactions (AUC=0.674; p=0.009) and level of energy in QoL, the NHP (AUC=0.633; p=0.045) was the most specific and sensitive. In the evaluation of the emotional aspect domain, the most accurate instrument was the NHP in the "emotional reaction" score (AUC=0.699; p=0.003). The evaluation of pain was limited in the three instruments and SF-36 was the only one in assess of the domains of social aspects and general health status.

CONCLUSION

For evaluation of the physical aspects in patients with RA, the HAQ is the most accurate. For evaluation of emotional aspects the NHP is the most indicated, although the SF-36 was the only one in the evaluation of general domains.

Minimal Clinically Important Difference as Applied in Rheumatology: An OMERACT Rasch Working Group Systematic Review and Critique

Objective.

We aimed to evaluate how minimal (clinically) important differences (MCID/MID) were calculated in rheumatology in the past 2 decades and demonstrate how the calculation is compromised by the lack of interval scaling.

Methods.

We conducted a systematic literature review on articles reporting MCID calculation in osteoarthritis (OA) and rheumatoid arthritis (RA) from January 1, 1989, to May 9, 2014. We evaluated the methods of MCID calculation and recorded the ranges of MCID for common patient-reported outcome measures (PROM). Taking data from the Health Assessment Questionnaire (HAQ), we showed the effects of performing mathematical calculations on ordinal data.

Results.

A total of 330 abstracts were reviewed and 123 articles chosen for full text review. Thirty-six (19 OA, 16 RA and 1 OA-RA) articles were included in the final evaluation. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was the most frequently reported PROM with relevant calculations in OA, and the HAQ in RA. Sixteen articles used anchor-based methods alone for calculation of MCID, and 1 article used distribution-based methods alone. Nineteen articles used both anchor and distribution-based methods. Only 1 article calculated MCID using an interval scale. Wide ranges in MCID for the WOMAC in OA and HAQ in RA were noted. Ordinal-based derivations of MCID are shown to understate true change at the margins, and overstate change in the mid-range of a scale.

Conclusion.

The anchor-based method is commonly used in the calculation of MCID. However, the lack of interval scaling is shown to compromise validity of MCID calculation.

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.

Measurement properties of physical function scales validated for use in patients with rheumatoid arthritis: a systematic review of the literature

Background

The aim of this study was to systematically review the content validity and measurement properties of all physical function (PF) scales which are currently validated for use with patients with rheumatoid arthritis (RA).

Methods

Systematic literature searches were performed in the Scopus and PubMed databases to identify articles on the development or psychometric evaluation of PF scales for patients with RA. The content validity of included scales was evaluated by linking their items to the International Classification of Functioning Disability and Health (ICF). Furthermore, available evidence of the reliability, validity, responsiveness, and interpretability of the included scales was rated according to published quality criteria.

Results

The search identified 26 questionnaires with PF scales. Ten questionnaires were rated to have adequate content validity. Construct validity, internal consistency, test-retest reliability and responsiveness was rated favourably for respectively 15, 11, 5, and 6 of the investigated scales. Information about the absolute measurement error and minimal important change scores were rarely reported.

Conclusion

Based on this literature review, the disease-specificHAQ and the generic SF-36 can currently be most confidently recommended to measure PF in RA for most research purposes. The HAQ, however, was frequently associated with considerable ceiling effects while the SF-36 has limited content coverage. Alternative scales that might be better suited for specific research purposes are identified along with future directions for research.

Rasch analysis of the Oxford Knee Score

OBJECTIVES

Use Rasch analysis to examine the psychometric properties of the Oxford Knee Score (OKS), particularly in respect to unidimensionality, and consistency of item functioning before and after total knee replacement and across age and gender groups.

METHODS

The 12-item OKS was administered to 1,712 patients before the surgery, and 1,322 and 855 patients were administered the instrument repeatedly at the 6-month and 2-year postoperative assessments, respectively. Data were fitted to the Rasch partial credit model with the Winsteps program. Differential item functioning (DIF) analysis was performed, and fit statistics in combination with principal components analysis of the residuals were used to test the unidimensionality assumption. The fit criteria were set at 1.5 and 2.0 for infit mean-square (MNSQ) and outfit MNSQ, respectively.

RESULTS

At baseline, item difficulty ranged from -1.86 to 1.78 logits, and person measures had a mean+/-SD of -0.01+/-0.89. Misfit items were "limping" and "night pain" in preoperative data and "limping" and "kneeling" in postoperative data. After removing items limping and kneeling and recoding item night pain, none of the items misfit at each of the time points and there was stability of item difficulty ordering across time. In the modified OKS set, five items displayed DIF by age and three by gender.

CONCLUSION

The original OKS had adequate targeting and good coverage of knee severity levels in preoperative patients. The modified 10-item OKS data fit the Rasch model and had stable item difficulty ordering over time.