“…The main difference between retention and length of stay was that there were no predetermined expectations about the required length of treatment (e.g., at least 7 days). Seven studies included outcomes relating to total length of stay in the facility [ 4 , 6 , 22 , 24 , 29 , 40 , 80 ]. Eight studies included outcomes relating to length of withdrawal treatment only [ 40 , 41 , 53 , 54 , 71 , 72 , 76 ].…”