Temporal and spatial trends of precocious puberty in France: a feasibility study

Background Precocious puberty (PP) is defined as the development of secondary sexual characteristics before the age of 8 in girls and 9 yrs in boys. The prevalence is about 10 times higher in girls than in boys. The disease is mostly due to the activation of the pituitary-gonadal axis (central PP) with no identified cause. Early environmental exposure to endocrine disruptors (ED) seems to impair sexual development and could play a causal role. Female PP incidence is suspected to have increased in some countries. Very few studies have been published on the incidence of PP at the scale of a whole country. Therefore a better knowledge on the epidemiology of PP is needed. Aims The objective of this study was to assess the feasibility of monitoring trends of PP in France based on medical-administrative databases. Methods To establish the diagnosis of PP, patients are mostly evaluated in day hospital. We counted all first hospital admissions related to PP (considered as a proxy of clinical suspicions of PP) between 2002 and 2011 based on data available from the French National Hospital Discharge Database. Cases were selected according to age, sex, and diagnosis. Zip code was available, thus allowing geographical distribution of cases to be studied. In addition we looked at the number of children actually treated for PP by GnRH analogs between 2010 and 2013, based on exhaustive data obtained from the French National Information System for Health Insurance. Zip code was also available. We analysed temporal and spatial trends based on these two indicators. Results We estimated incidence rates and temporal trends for clinical suspicions and geographic disparities for clinical suspicions and treated PP. We observed marked geographical disparities. Conclusions This is the first study describing trends based on PP evaluation and treatments at the scale of a whole country. Interpretation of the results needs to focus on several limits, such as temporal and geographical differences in medical practices regarding PP definition, evaluation and management.