Adherence to anti-tuberculosis treatments by patients using an instrument based on the health belief model

Introduction: Several studies report a persistently high rate of non-adherent patients globally, with tuberculosis patients failing to comply with prescribed regimens. Adherence rates often decline during advanced treatment phases due to patients feeling cured, treatment fatigue, or obstacles related to access and employment. The aim of the study was to compare TB patient’s adherence to treatment using two instruments: the researchers AMI-TB and the MMAS-8 questionnaire. Research Methodology: This study employed a cross-sectional observational design with descriptive assessments using two adherence-related instruments. No intervention or repeated measurement was performed. The study population consisted of all registered patients diagnosed with tuberculosis undergoing anti-tuberculosis treatment, totaling 489 patients. A total of 148 respondents participated in this study using simple random sampling. Data were collected using the MMAS-8 and AMI-TB questionnaire. Data analysis included univariate and bivariate analyses using an independent t-test with a significance level of p < 0.05. Results: The average treatment status measured using MMAS-8 was 6.48 (standard deviation = 1.48), and using AMI-TB was 59.13 (standard deviation = 4.13). A previously reported p value of 0.005 resulted from a raw-score comparison; this does not constitute a valid test of comparative adherence because the instruments have different score ranges and conceptual targets. Conclusion: The findings describe adherence-related scores obtained using two conceptually different instruments in the participating tuberculosis services. MMAS-8 assesses self-reported medication-taking behavior, whereas AMI-TB addresses selected Health Belief Model perceptions. These results do not demonstrate superior validity, accuracy, or interchangeability of either instrument. Further study-specific reliability, construct validity, criterion validity, and clinical outcome analyses are needed before recommending routine comparative use. Questionnaires based on the health belief model can be used to measure TB patients' adherence to anti-tuberculosis treatment.