(as cited in Brands & Brands, 1998, 2) found that MMT had substantially higher retention rates (68% after three months) compared to outpatient counselling without methadone (36%) or residential programs without methadone (45%).
(cités dans Brands & Brands, 1998, 2) ont trouvé que le TEM permettait d'obtenir des taux de rétention considérablement plus élevés (68 p. 100 après trois mois) que le counseling externe sans méthadone (36 p.