[REIN: a tool to evaluate practices].

On the occasion of the 20th anniversary of the REIN (French Renal Epidemiology and Information Network), a summary work on the contributions of the national French ESKD register was carried out. On the issue of its role in practices evaluation, the following key messages were retained. The evaluation of our practices allows improving them as proposed by the concept of the Edward Deming wheel (Plan, Do, Check, Act). Measurement also allows setting goals and targets. Where there are recommendations available, the REIN indicators allow comparison with the identified targets. The REIN registry is an interesting tool to observe the deployment and impact of the recommendations in dialysis units and to evaluate the professional practices taking into account the patients’ characteristics and the changes in the recommendations. Finally, the treatment indicators analysed using REIN data show the great diversity of practices from one region to another, the result of habits, training of nephrologists, the history of the care offered and sometimes the geography of the region and its population.