Applicability of the bayesian methodology to the study of low incidence diseases : example of child anxiety

Abstract

This work is a cross-sectional quantitative study that provides information about anxiety symptoms from the CECAD questionnaire, applied to 500 students aged 8-12. Anxiety prevalence was estimated using three different procedures, both in the total sample and in a subsample of 10 children, randomly selected. Results showed a prevalence range of childhood anxiety for the three methods of 16.5%-23.5%, 16.7%-23.7%, and 18.3%-24%, when using the large sample. When the small sample size was used, the frequentist estimation method yielded impossible values, but results when using Bayesian methods were between 2.3% and 41.3% in the non-informative distribution, and between 17.9% and 27.4% in the informative distribution. The Bayesian method was found to be the procedure that provided better estimation, with improved results when informative distribution was used since it adds relevant information.