ABSTRACT
OBJECTIVE: To investigate the time trend and geographic distribution of treated patients with congenital hypothyroidism (CH) and explore their possible relationship to the availability of endocrinologists in Japan. STUDY DESIGN: The 2-source capture-recapture method was used to estimate the total number of patients. The ratio of the total estimated number of patients with CH to the number of endocrinologists and Spearman correlation coefficients were calculated. Curve fitting for changes in incidence or prevalence was estimated. RESULTS: The incidence and prevalence of CH exhibited upward trends, with linear slopes of increase during the period 1994-2002. A statistically significant positive correlation was observed between the prevalence of CH and the ratio of the number of patients with CH to the number of endocrinologists in the 10 regions studied. The prevalence of CH was significantly higher in the regions with a higher ratio of patients with CH to endocrinologists, and also in younger patients. CONCLUSIONS: A shortage of endocrinologists may be one reason for the upward trend in the incidence and prevalence of treated patients with CH.