CLINICAL PHENOTYPES OF VOMITING SYNDROME IN INFANTS: CLUSTER ANALYSIS AND NOSOLOGICAL VALIDATION

Aim - to identify clinical phenotypes of vomiting syndrome in infants using signs recorded at initial examina­tion, independently of the reference diagnosis. Materials and methods. Data of 89 infants (0-12 months, 2019-2025) were analysed; organic pathology in 52 (pyloric stenosis - 42, duodenal obstruction - 10), functional disorder in 37. K-means cluster analysis was performed in 66 patients with complete data on seven variables. Results. Three pheno­types were identified (k=3; silhouette=0.337): functional (n=19), pyloric obstruction (n=40) and distal obstruction (n=7); differences were significant for all variables (p<0.002). Concordance with the reference diagnosis was 83.3% (95% CI 72.6-90.4); sensitivity 97.4%, specificity 66.7%, negative predictive value 94.7%. Length of stay was 6.06±2.48, 7.47±3.11 and 18.14±7.24 days (p=0.0004). Conclusion. The clinical presentation reflects the nosological structure with 83.3% accuracy even without diagnostic information; phenotyping is appropriate as a first, screening step of diagno­sis.