Dysphagia Screening in Acute Stroke: Adaptation and Validation of the Modified Volume-Viscosity Swallowing Test With International Dysphagia Diet Standardization Initiative Standards

Objective: To adapt and validate the modified Volume-Viscosity Swallowing Test (MV-VST), aligned with the International Dysphagia Diet Standardization Initiative (IDDSI) framework, and to enhance its applicability in diverse dietary contexts, particularly in lower-middle-income countries. Design: A cross-sectional study. Setting: The research was carried out at an acute care tertiary hospital. Participants: Seventy patients (N=70) with acute stroke, aged ≥18 years, with a standard education level and no sensory deficits, were included in the study. Interventions: Not applicable. Main Outcome Measures: The study consisted of 2 phases. In phase 1, the MV-VST was adapted using IDDSI guidelines with varied viscosities and volumes and validated by 5 experienced swallow specialists. In phase 2, the test was used to screen swallowing safety, swallowing efficacy, and temporal parameters across different consistencies and volumes. In addition, clinical assessment was performed using standardized test batteries (Functional Oral Intake Scale [FOIS] and Eating Assessment Tool [EAT-10]), and a subset of participants underwent a videofluoroscopic swallow study (VFSS). The primary outcome of MV-VST measured parameters were defined as clinical indicators that predict potential deficits, and their correlations with FOIS, EAT-10, and VFSS. Furthermore, the study examined the reliability and validity of the adapted swallowing screening tool, MV-VST. Results: Of the 70 participants, 62.8% experienced dysphagia. The MV-VST demonstrated significant correlations with clinical assessments (FOIS and EAT-10), showing high test–retest and interrater reliability (Cronbach's α=0.994). Sensitivity and specificity were 87.5% and 100% for EAT-10, respectively, and 75% and 100% for VFSS, respectively. The tool demonstrated its ability to predict potential deficits in swallowing safety, efficacy, and temporal aspects, with significant differences observed between participants based on MV-VST outcomes. Conclusions: The adapted MV-VST, using IDDSI standards, is a reliable and valid tool for the early identification of poststroke dysphagia, facilitating timely intervention. Despite limitations like the single-center design and small sample size, the study underscores the potential of the MV-VST in diverse dietary practices. Future research should focus on larger, multicenter studies and integrating advanced technologies for more precise assessments.