[Observational studies in osteoporosis treatment]

Osteoporosis is characterized by increased fracture risk, with associated severe morbidity and mortality. Several pharmacological treatments have been demonstrated to be effective in reducing fracture risk, by means of Randomized Controlled Trials (RCTs). However, it seems that the results of these RCTs could not be immediately generalized to the "real-world" population. It has been calculated that less than 20% of the subjects included in the RCTs may be representative of the general population treated for osteoporosis in clinical practice, due to the very strict inclusion and exclusion criteria of these trials. In the last years, some observational studies on osteoporotic-treated patients have been carried out in those Countries where wide administrative claims database are available. These studies may be useful because of the large "real-world" population sample included, the possibility to control for several comorbidities and active treatments, and the opportunity to follow patient outcome over time, even comparing the clinical effects of the different drugs used for fracture prevention. However, their results should be considered with caution, due to the potential bias in the diagnosis of fracture, adherence assessment, type of treatment followed by the patients, and the impossibility to control for several characteristics influencing bone health as well as treatment outcomes. As discussed in the paper, the results of these studies tend to confirm, at least in some cases, the results of the RCTs for fracture prevention, confirming that the drugs currently used for osteoporosis treatment are actually effective in clinical practice as well.