# Psychometric properties of an Arabic language version of the Treatment Adherence Questionnaire among dialysis patients with cardio renal syndrome

## TL;DR

This study validates an Arabic version of a treatment adherence questionnaire for dialysis patients with cardio renal syndrome in Yemen.

## Contribution

The study provides a culturally adapted and psychometrically validated Arabic version of the Treatment Adherence Questionnaire (TAQ-Ar).

## Key findings

- The TAQ-Ar demonstrated strong semantic equivalence and content validity with a Content Validity Index of 0.88.
- Exploratory factor analysis identified four factors with an overall average factor loading of 0.683, confirming validity.
- The questionnaire showed excellent internal consistency (Cronbach's alpha = 0.948) and good test-retest reliability (ICC = 0.776).

## Abstract

Assessing or measuring adherence is the initial step toward comprehending it, or the lack thereof.

This study aims to translate and validate the Treatment Adherence Questionnaire TAQ among Yemeni dialysis patients with cardiorenal syndrome.

This cross-cultural adaptation study was conducted at two dialysis centers in Hadhramout Governorate, Yemen, between January 10 and February 15 of 2021. The English version of TAQ was translated into Arabic using the Beaton translation process. Psychometric tests of the TAQ were performed on 100 patients with cardiorenal syndrome. For face and content validity, the pre-final version of the TAQ Arabic was tested using a convenience sample of 10 patients. Individual interviews were used to investigate the meaning, comprehensibility, and acceptability. To evaluate the factor loadings, discriminant validity, and internal consistency of the TAQ Arabic version (the TAQ-Ar), one hundred patients were selected in the same manner and using the same inclusion criteria. Exploratory Factor Analysis (EFA) was utilized to ascertain the underlying factor structure of the Arabic version of the questionnaire, as its dimensionality had not been previously determined in this group. We employed principal component extraction with promax rotation to produce a clear and understandable factor solution. To assess reproducibility, 30 patients were chosen randomly from 100 to resubmit the questionnaire 2 weeks after the initial administration and under the same conditions.

The transcultural adaptation process revealed that all TAQ-Ar items and patient descriptions exhibited full semantic equivalence. During the psychometric validation phase, the scale-level Content Validity Index was 0.88, and cognitive interviews (n = 30) confirmed patient clarity. Exploratory factor analysis identified four variables, aligning with the structure suggested by the original instrument inventor. Based on Bandalos' standards, factors were kept if their eigenvalues were more than 1 and their factor loadings were higher than 0.30. The overall average factor loading was 0.683, which shows that the test was valid. Internal consistency was very good (Cronbach's alpha = 0.948), and test-retest repeatability showed significant stability (ICC = 0.776).

We confirm that the TAQ-Ar is suitable for assessing treatment adherence in individuals with Arabic as their first language for cardiorenal syndrome disease.