A Cochrane review included 9 studies testing 10 interventions for short-term treatments and 69 studies testing 81 interventions for long-term treatments. These included eleven studies in hypertension, 10 in schizophrenia or acute psychosis, and eleven in asthma (and / or chronic obstructive pulmonary disease COPD). For short-term treatments, four of ten interventions reported in nine RCTs showed an effect on both adherence and at least one clinical outcome. For long-term treatments, 36 of 81 interventions reported in 69 RCTs were associated with improvements in adherence, but only 25 interventions led to improvement in at least one treatment outcome. Almost all of the interventions that were effective for long-term care were complex, including combinations of more convenient care, information, reminders, self-monitoring, reinforcement, counseling, family therapy, psychological therapy, crisis intervention, manual telephone follow-up, and supportive care. Even the most effective interventions did not lead to large improvements in adherence and treatment outcomes.
Comment: The quality of evidence was downgraded by imprecise results (limited study size for each comparison).