Confirmatory factor analysis of the Malaysia medication adherence assessment tool (MYMAAT) among patients with chronic medications

• Main Author: Tian, Ong Gaik
• Format: Thesis
• Language: English
• Published: 2024
• Subjects: R Medicine; RS1-441 Pharmacy and materia medica
• Online Access: http://eprints.usm.my/61110/1/Ong%20Gaik%20Tian-E.pdf; http://eprints.usm.my/61110/

The MyMAAT was developed using Exploratory Factor Analysis and the current study intends to confirm the measurement model, dimensionality and ensure the factor structure by Confirmatory Factor Analysis (CFA). A cross-sectional study was conducted using a self-report questionnaire at six health facilities in the Federal Territories Kuala Lumpur and Putrajaya Health Department between May to November 2023. Participants with age≥18 years old, prescribed with one or more chronic medications for at least six months and understand English or Malay language were selected using quota sampling. There were two constructs in the MyMAAT, namely the Specific Medication-Taking Behaviour (Factor 1) with eight items and the Social-Cognitive Theory of Self-Efficacy and Social Support (Factor 2) with four items. There were 470 participants which comprised of Malay (62.7%), Chinese (24.0%) dan Indian (12.2%). Most participants had five drugs or less (81.3%). The final model for the Malay version of the MyMAAT retained the two constructs and 12 items with good fit: CFI=0.978, TLI=0.973, RMSEA=0.036(90%CI 0.001,0.067) and with good composite reliability CR=0.790 for Factor 1 and CR=0.787 for Factor 2. The factor loadings ranged from 0.413 to 0.832 with p-value<0.001 The AVE for Factor 1 was 0.664 and for Factor 2 was 0.491. There was a strong correlation (ρ=0.507, p < 0.001) between the Malay version of the MyMAAT with the Malay version of the MMAS-8 by adherence category from the data of 191 participants. The final measurement model of the English version did not achieve the minimum level of good fit to the data: CFI=0.933, TLI=0.917, RMSEA=0.073(90%CI 0.052,0.094) but had good composite reliability CR=0.802 for Factor 1 and CR=0.852 for Factor 2. The factor loadings ranged from 0.347 to 0.845. The AVE was 0.630 for Factor 1 and 0.392 for Factor 2. Fifty-two participants completed the test-retest after five to ten days from the first administration. The Malay version had moderate to excellent reliability based on ICC=0.932(95%CI:0.661,0.986) for Factor 1 whereas Factor 2 had poor to excellent reliability based on ICC=0.956(95%CI:0.325,0.997) by using the Two-Way Mixed Model and Consistency type. The English version had moderate to excellent reliability based on ICC=0.911(95%CI:0.554,0.982) for Factor 1 whereas Factor 2 had poor to excellent reliability based on ICC=0.941(95%CI:0.092,0.996). It can be concluded that the Malay version of the MyMAAT is valid and reliable in measuring medication adherence among participants with chronic medication(s), but the English version needs to be improved and then re-tested