Psychometric properties of the 12-item Knee injury and Osteoarthritis Outcome Score (KOOS-12) Spanish version for people with knee osteoarthritis

A scoping review of patient self-report measures of flare in knee and hip osteoarthritis (OA): A report from the OMERACT flares in OA working group

PURPOSE

We aimed to analyze the content validity/domain match and feasibility of self-report instruments that could measure flare in osteoarthritis (OA), by extending our 2017 literature review on the definition of flare in knee and hip OA.

METHOD

We searched PubMed (Medline), Web of Science and PsycInfo (Ebsco Host) databases for original articles reporting research about flare (or synonyms) in humans with knee and hip OA, between 2017 and 2023. Four experts worked independently, checking the records, and assessing content validity and feasibility, writing justification for exclusion.

RESULTS

At literature review phase, 575 papers were filtered. After experts' analysis, 59 studies were included, and 44 instruments associated with flare in OA were identified. Most were studies about pain in knee or hip OA (35 %), cultural adaptation of a measure (33 %) or studies investigating psychometric properties of full (16 %) or short form (4 %) instruments. The assessment of domain match and feasibility revealed that 15 instruments were assigned a label of 'yes' or 'uncertain' as to whether or not there was a good match with the domain concept or whether the instrument was considered feasible to use.

DISCUSSION

Most identified instruments considered different aspects of pain and the associated discomfort in performing daily activities but did not include the central aspects of flare in OA, i.e. the change of state, nor the additional Outcome Measures in Rheumatology (OMERACT) endorsed domains for OA flare namely stiffness, swelling, psychological aspects, impact of symptoms including fatigue and sleep disturbance. Although it is possible that the period specified to conduct this literature review may have led to some recognized instruments being excluded, this review demonstrates the need for the research community to reach consensus on the best way to measure self-reported flares in future clinical trials and observational studies.

Exploration of the psychometric properties of the novel General Medication Adherence Scale (GMAS) for chronic illness patients

OBJECTIVE

Many related scales have been developed and applied to measure patients' medication adherence, but the research on the psychometric characteristics of the scale still requires further studies. This study aims to provide further validation of the GMAS scale by using Rasch analysis and to make targeted recommendations for scale improvement.

METHODS

This is a cross-sectional study using secondary data. 312 Chinese adult patients were recruited from two tertiary hospitals and one community health service center in Tianjin to complete a questionnaire containing the GMAS, from January to June 2020. Participants included to have at least one chronic condition and also have been on medication for more than 3 months, but excluded patients with major life-threatening illnesses (e.g. heart failure, cancer), cognitive impairments preventing clear expression and significant communication difficulties. Rasch analysis was used to explore the psychometric properties of the GMAS scale. Key indicators including unidimensionality, validity and reliability, differential item functioning and degree of fit with Rasch model are validated.

RESULTS

After fitting the Rasch model for the first time, 56 samples poorly fitting the model were deleted. The remaining 256 samples were used for Rasch analysis. The results show that GMAS can fit the Rasch model well, which proves that the scale has favourable psychometric characteristics. But some items had differential item functioning in whether patients have comorbidities.

CONCLUSION

The GMAS was found to be useful as a screening tool for patients' medication adherence problems reported, except some issues to be addressed for further improvement of the scale.

Translation and validation of the Chinese version of the general medication adherence scale (GMAS) in patients with chronic illness

OBJECTIVE

To translate the English version of general medication adherence scale (GMAS) into a Chinese version and test its reliability and validity in Chinese patients with chronic diseases.

METHODS

After translating the original English version into Chinese (GMAS-C) following the forward-backward translation and expert review procedure, we conducted a pilot study among 10 chronic disease patients. Each patient took about 10 min to complete the scale and was asked about the difficulty of understanding or filling the scale. Then a total of 312 patients aged 18 years or older with chronic illness were selected from the outpatient departments of two tertiary hospitals and a community center in Tianjin from April 2019 to May 2020 by convenience sampling. Cronbach's α coefficient, item-total correlation and test-retest reliability were used to evaluate the scale reliability; expert evaluation method was used to evaluate the content validity of the scale; and exploratory factor analysis, confirmatory factor analysis, and known group validity were used to evaluate the construct validity of the scale.

RESULTS

As a result of the adaptation process, the GMAS-C's structure was determined. It included 3 dimensions and 11 items and was reliable and valid for Chinese patients with chronic diseases. Total Cronbach's α coefficient of the scale was 0.781 and test-retest reliability coefficient was 0.883 after two weeks. The item-level content validity indexes (CVIs) were ≥ 0.78 for all items. A Kaiser-Meyer-Olkin test and Bartlett' test of sphericity test indicated that the sample met the requirements of factor analysis. Exploratory factor analysis extracted three factors with eigenvalue >1, and 60% of the total variance was explained by three-factor solution. Confirmatory factor analysis showed acceptable fit indices (χ²/df = 1.58, IFI = 0.96, TLI = 0.94, CFI = 0.96 and RMSEA = 0.05).

CONCLUSIONS

The GMAS-C demonstrates satisfactory reliability and validity. This scale can be a clinically useful tool to identify the levels of medication adherence and possible barriers for adherence of the medication regime in patients with chronic diseases.

Validation of a Spanish Version of the Health Assessment Questionnaire-II to Assess Mexican Patients' Physical Function with Rheumatoid Arthritis

OBJECTIVE

To evaluate the validity, reliability, and performance of the Health Assessment Questionnaire-II(HAQ-II) Spanish version questionnaire to measure physical function.

METHODS

A cross-sectional study of 496 patients with rheumatoid arthritis, distributed in 2 samples. The construct validity was evaluated employing the confirmatory factor analysis and the validity based on the relationship with other variables. Cronbach's alpha (α) and McDonald's omega (ω) coefficient were used to determine reliability. Item performance was analysed by fitting different models of item response theory.

RESULTS

The one-factor model presented a poor fit in the confirmatory factor analysis; an exploratory factor analysis was carried out, which suggested a 2-factor structure. The confirmatory factor analysis in the second sample confirmed that the second-order model had a good fit to the data. The general factor explained more than 70% of the variance. The reliability indices showed adequate internal consistency (α=.92-.95; ω=.88-.93). Ninety-three percent of the contrasting hypotheses about the relationship of the HAQ-II scores with other variables were confirmed, demonstrating their convergent, divergent, and known group validity. The multidimensional graduated response model was the one that best predicted person's interaction with the items.

CONCLUSION

The Spanish version of the HAQ-II presents adequate validity and reliability for measuring Mexican patients' physical function with rheumatoid arthritis.