Association of a Smartphone-Based mHealth Intervention with Knowledge, Attitude, and Practice Regarding Treatment Adherence and Adverse Events Among Patients with Multidrug-Resistant Tuberculosis in Vietnam: A Nested Cross-Sectional Study Within the V-SMART Randomised Controlled Trial

BackgroundMobile health (mHealth) interventions have shown promise in supporting tuberculosis care, but their association with patient knowledge, attitudes, and practices (KAP) among people with multidrug-resistant tuberculosis (MDR-TB) remains poorly evaluated in high-burden, programmatic settings. We assessed the association between a smartphone-based mHealth application and KAP regarding treatment adherence and adverse events within the V-SMART randomised controlled trial in Vietnam.MethodsThis nested cross-sectional study included 528 patients with MDR-TB (278 intervention, 250 control) enrolled across seven provinces in Vietnam between 2023 and 2025. KAP was measured using a validated questionnaire (Knowledge 0–17, Attitude 0–44, Practice 0–19, total 0–80). Multivariable linear regression adjusted for age, sex, province, education, time on treatment, PHQ-9, stigma, and social support. Dose-response relationships with self-reported app usage were examined in the intervention arm.ResultsThe mHealth intervention was associated with higher total KAP scores (adjusted mean difference 5.0 points, 95% CI 3.3–6.7, p<0.001), with largest gains in practice (+2.2 points) and knowledge (+1.1 points). Clear dose-response relationships were observed: each additional month of app use was associated with a 0.81-point increase in total KAP score (p<0.001).ConclusionThe smartphone-based mHealth intervention was associated with meaningfully higher KAP scores among MDR-TB patients in Vietnam. These findings support integration of mHealth tools into routine programmatic management of drug-resistant tuberculosis in high-burden settings.