Adherence as a mediator of olfactory improvement in digitally-guided versus text-based olfactory training.

OBJECTIVES: To compare the efficacy of WeChat-guided olfactory training (WG-OT) versus text-based olfactory training (TB-OT) in improving odor identification and enhancing adherence in patients with persistent olfactory dysfunction (OD), and to evaluate the mediating role of adherence and psychological outcomes. METHODS: A prospective cohort study was conducted from March 2024 to June 2025. A total of 113 adults with moderate-to-severe OD were randomized to WG-OT (n = 50) or TB-OT (n = 63). Both groups performed twice-daily exposure to four odorants for 12 weeks. Primary outcomes were changes in odor threshold (T) and identification (I) measured by Sniffin’ Sticks. Secondary outcomes included adherence rates, PHQ-9 depression scores, QOD (Questionnaire of Olfactory Disorders), and endoscopic scores (OCES). RESULTS: WG-OT demonstrated significantly higher adherence (89.4%) compared to TB-OT (78.3%; p < 0.001) and greater improvement in odor identification (ΔI: 6.72 ± 4.48 vs. 3.73 ± 3.39; MD = 2.99, 95%CI:1.47–4.51; p < 0.005). Adherence mediated 42% of the treatment effect (Sobel Z = 2.65, p = 0.008). No between-group difference was found in threshold improvement. TB-OT was associated with a greater reduction in depressive symptoms (ΔPHQ-9: −0.81 ± 1.17 vs. −0.28 ± 1.11; p < 0.05). Furthermore, baseline QOD scores were inversely correlated with olfactory function (identification: r = -0.35, p < 0.001; threshold: r = -0.31, p = 0.001) and predicted less post-intervention QOD improvement (r = -0.42, p < 0.001). CONCLUSION: WeChat-guided OT significantly improves odor identification through enhanced adherence, particularly in post-viral OD. Text-based OT may offer superior psychological benefits. Baseline olfactory-specific quality of life (QOD) is a potential prognostic indicator for rehabilitation response. Hybrid approaches should be explored to optimize both sensory and mood outcomes. LEVEL OF EVIDENCE: 2b.