“…In fact, only 7 of the studies discussed in the present review conducted follow-up evaluations at 12 months 39,46 or more, 28,34,36,38,44,48 with drop-out rates ranging between 5% for the 2 studies with 12month follow-up, 39,46 and 37-49% for two studies with a follow-up of 20 months 28,44 and 36-48 months. In fact, only 7 of the studies discussed in the present review conducted follow-up evaluations at 12 months 39,46 or more, 28,34,36,38,44,48 with drop-out rates ranging between 5% for the 2 studies with 12month follow-up, 39,46 and 37-49% for two studies with a follow-up of 20 months 28,44 and 36-48 months.…”