3.1 | Statistics
The sampled data were recorded and analyzed by SPSS (version 27.0.1.0 SPSS, Inc, Chicago, III).
In univariate analysis, the non-parametric Mann-Whitney U-test (two groups) was first used to compare continuous IgE values in subjects with or without a given clinical involvement; then, each variable of interest was dichotomized (as negative or positive) to study the proportion of subjects with symptoms in the two groups thus obtained.
Pearson’s χ2 test or Fisher’s exact test (used for two-by-two contingency tables with less than 50 cases) were used to assess if paired observations on two variables expressed in a contingency table, were independent of each other.
We performed multiple logistic regression for the clinical variables with dichotomous scores (present, absent) to see whether the association between clinical symptoms and different shellfish allergens reactivity was present after simultaneously adjusting for the other variables of interest.
The degree of relationship between the quantitative variables studied was analyzed using Spearman Correlation (rho) test, and the most commonly used bivariate correlation technique. A value of p < 0.05 was considered statistically significant.