Explore the Overall Benefit Index and its correlation with item difficulty among dysphagia-related syndromes in the ICF framework.

Background: Individuals with dysphagia typically experience multiple co-occurring symptoms, whose interrelationships can vary in strength. The significance and impact of each symptom within dysphagia also differ. However, the intricate web of connections among these symptoms remains poorly understood, making it challenging to assess the importance of individual symptoms from a relational perspective.

Aim: The aim of this study was to: 1) construct a correlation map that identifies the risk associations within dysphagia-related syndromes; and 2) rank syndromes according to the Overall Benefit Index (OBI) of a specific functional intervention, which varies in their impact on the overall functional status.

Design: This study has a cross-sectional design.

Setting: The setting of this study was a tertiary hospital in Hunan Province, China.

Population: Population considered in this study included patients with non-esophageal dysphagia.

Methods: Adopting convenience sampling, we recruited 150 patients with dysphagia to assess their health-related quality of life through the dysphagia-specific International Classification of Functioning, Disability and Health (ICF) Scale. A network structure of 50 second-level or third-level ICF categories was investigated by the Ising model. The Bayesian model was applied to determine the probability of the existence of the connection among ICF functional categories.

Results: The resulting network consisted of 50 nodes and 64 connections. 48 functional categories demonstrated a significant OBI, with "d9102 Ceremonies" (OBI=1.00) achieving the highest OBI. "d9204 Hobbies" (OBI=0.862), and "d9205 Socializing" (OBI=0.847) were another top two categories with the 2^nd and 3^rd highest OBI. There was a significant correlation between network parameters, OBI, and item difficulty. Specifically, item difficulty showed a positive correlation with OBI (P<0.001, rPearson=0.712), indicating that more challenging items tend to correspond with higher OBIs.

Conclusions: The Ising model is a powerful tool that can assist rehabilitation clinicians in better understanding the complex functional network and guide specific rehabilitation interventions for patients with dysphagia.

Clinical rehabilitation impact: Cooperating the item difficulties from the Item Response Theory (IRT) into the OBI from the Ising model could guide individualized clinical decisions based on item difficulties and importance.