Chou WY, et al. - Prognostic factors for the outcome of extracorporeal shockwave therapy (ESWT) for calcific tendinitis of the shoulder were identified in this study. Poor prognosis was found to be significantly associated with Gartner type I calcification, calcification extent > 15 mm and duration of symptoms > 11 months. A different procedure was recommended for patients who had the factors identified for a poor outcome after ESWT.