Translation and validation of the Test of Adherence to Inhalers (TAI) questionnaire among adult patients with asthma in Malaysia

Abstract

Objective

The Test of Adherence to Inhalers (TAI) is a validated self-reported questionnaire that can reliably assess adherence to inhalers through patient self-report. However, it was not available in Bahasa Melayu (BM) language, nor has it been validated for use in the Malaysian population. The study aimed, therefore, to translate the 10-item TAI questionnaire into BM and evaluate its psychometric properties.

Methods

The translation of the English version of the valid 10-item TAI questionnaire into BM was followed by subjecting it to a series of tests establishing factorial, concurrent and known group validities. Concurrent validity was assessed through Spearman’s rank correlation coefficient against pharmacy refill-based adherence scores. Known group validity was assessed by cross-tabulation against asthma symptom control and using chi-square test. The internal consistency of the test scale was determined by a test-retest method using Cronbach’s alpha (α) value and intraclass correlation coefficients.

Results

A total of 120 adult asthma patients participated in the study. A 2-factor structure was obtained and confirmed with acceptable fit indices; CFI, NFI, IFI, TLI >0.9 and, RMSEA was 0.08. The reliability of the scale was 0.871. The test-retest reliability coefficient for the total sum score was 0.832 (p < 0.01), which indicated good reliability. The 10-item TAI-BM established concurrent and known group validities. The sensitivity and specificity of the tool were >85%.

Conclusions

The scale successfully translated into BM and validated. The 10-item TAI-BM appears fit for use in testing inhaler adherence of Malaysian patients with asthma.

Keywords:

• Treatment
• therapy

Acknowledgment

The authors would like to thank the Director General of Health Malaysia for the permission to publish this paper. We are also grateful to Universiti Sains Malaysia for the support. This study was funded by the Research University (RUI) Grant, Universiti Sains Malaysia (Grant Account Number: 1001/PFARMASI/8012267). Finally, we would like to express our special gratitude to Hospital Kuala Kubu Bharu, Selangor, especially the pharmacy department for the cooperation and facilitation of the present study. The views expressed in this study are those of the authors and not necessarily those of the Universiti Sains Malaysia or Ministry of Health, Malaysia.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.