Long term corticosteroid therapy concerns 0.5 to 1% of the population and about 2.5% of elderly subjects. It is currently used as a cornerstone therapy in a wide variety of clinical contexts. The central problematic of prolonged corticosteroid therapy is the burden of adverse events associated with its long term use, including bone, metabolic and infectious complications. The management of patients for whom the prescription of long term corticosteroid therapy is indicated should include an evaluation of the individual risk and implementation of the appropriate preventive measures. Such an approach should particularly include cortisonic osteoporosis prevention, infectious prevention including vaccination, prevention of adrenal insufficiency, promotion of physical activity, as well as dietary management. In France, nurse-led prevention programs are highly developed for patients initiating immunosuppressive targeted therapies. Conversely, there are no dedicated nurse-led programs for patients starting prolonged corticosteroid therapy, for several historical and economical reasons. The implementation of such programs is likely to be beneficial at different levels, including the reduction of the number of adverse events and improvement of health-related quality of life. The main objective of the study is to determine the long-term benefit of a nurse-led prevention program among patients starting long-term corticosteroids therapy, compared to routine care.