<qa>  What is the main concern for improvement of quality and safety of care in elderly patients?We suppose that many of hospitalized elderly have at least one prescribed medication without valid indication. Conversely, many diseases are currently undertreated in elderly patients: e.g. medicines used to treat heart failure and osteoporosis are underused in 20 to 70 of patients. Moreover, PMI prescription is associated with an increased of morbidity, mortality, risk of drug-related adverse events, utilization of health care system, care costs and impairment of quality of life. Thus, optimization of drug prescription is a major concern for improvement of the quality and safety of care in elderly. 