Exploring the psychogastroenterology patterns of functional dyspepsia and irritable bowel syndrome comorbidities...

Comorbidities between different subtypes of functional gastrointestinal disorders (FGIDs) are highly prevalent in clinical practice. The heterogeneity of clinical appearance of these comorbidities causes difficulties with individualized diagnosis and comprehensive treatment of FGIDs. In this study, we aimed to estimate and interpret the psychology-gastroenterology interaction patterns of FGIDs for heterogeneous clinical appearances against the traditional anatomic diagnosis criteria.

In a retrospective cross-sectional study, the intensities of clinical appearances covering gastrointestinal symptoms, systemic symptoms, psychological disorders, and environmental sensitivity were collected using a self-administered questionnaire. Then, a multidimensional assessment framework was applied to estimate the quantitative model using structural equation modeling (SEM) and item response theory (IRT). The latent traits of each patient were evaluated using multidimensional computerized adaptive testing (MCAT). Lastly, the clinical patterns were estimated using either the original symptom intensity or quantified trait scores to interpret the psychology-gastroenterology interaction characteristics of FGIDs.

A total of 996 patients diagnosed with functional dyspepsia (FD) or irritable bowel syndrome (IBS) were enrolled in the study; the comorbidities of these two subtypes were observed along with the heterogeneities of their clinical appearances. The multidimensional framework was evaluated to be adequate based on the following parameters for SEM: Chi-square/df = 3.45, comparative fit index (CFI) = 0.92, goodness-of-fit index (GFI) = 0.96, root mean-squared error of approximation (RMSEA) = 0.05, Tucker-Lewis index (TLI) = 0.90, and root mean-squared residual (RMR) = 0.02. Based on the 5-dimension latent trait scores, the 7-latent-profile model was evaluated to be adequate for representing the heterogeneity of patients with comorbidities between FD and IBS (entropy = 0.98, Lo-Mendell-Rubin likelihood ratio test (LMRT) p-value < 0.01, bootstrap likelihood ratio test (BLRT)-p-value < 0.01). The model also represented different patterns of psychology-gastroenterology interactions for the heterogeneous clinical appearances.

Through the application of multidimensional variable analysis, the paradigm proposed in this study equips clinicians with an approach for quantifying and interpreting the complex clinical patterns of FGIDs.