The Epidemiological Characteristics of Autoimmune Thyroiditis in the Tuzla Canton in the Period from 2015 to 2020.

Background: Bosnia and Herzegovina (B&H) is one of the countries of Southeast Europe with the lack of data about chronic autoimmune thyroid diseases (CAITD) epidemiology.

Objective: This research aimed to assess incidence of CAITD in the Tuzla Canton of B&H during a 6-year period (2015-2020).

Methods: We retrospectively evaluated 82,000 hospital records of inpatients and outpatients with possible thyroid symptoms residing in Tuzla Canton of B&H (total of 445,028 inhabitants). The study included patients with laboratory and clinical proof of autoimmune thyroid diseases (AITD). Incidence rates were calculated with age standardisation using European standard population. Trends in incidence were evaluated as moving three-year averages.

Results: During the observed period, 1875 patients satisfied the diagnostic criteria for CAITD with male to female ratio of 1: 8.01. Median age of all cases was 46 years (interquartile range: 31 to 61) and women and men were on average the same age at the time of diagnosis. The overall standardized incidence was found to be 71.25 per 105 (%95 CI=63.36-79.15). The overall standardized incidence in men was 16.25 per 105 and 123.74 per 105 in women. In the end of the observed period, AITD prevalence was 427.52 per 105 (% 95 CI=408.17-446.87).

Conclusion: There was a slight decline of incidence in our region during the observed period. This decrease might be the result of combination of various factors, mainly the Corona epidemics outbreak and emigration. On the basis of the lower incidence rate in the Tuzla Canton, one can assume that iodine prophylaxis carried out in order to eradicate goitre had satisfied expectations because there had not been any enormous increase in patients with AITD.