Sixteen RCTs (3,305 patients, range 37 to 902) were included. Follow-up time ranged from two weeks to 12 months, with a median of six months. Where reported, mean percentage of patients included at follow-up was 79.8% ranging from 28 to 100%. Studies were of limited quality overall. Few studies reported using intention-to-treat analyses and allocation concealment methods.
Patient education and information (two studies)
One trial showed that a multidisciplinary intervention significantly enhanced medication adherence compared to control. Another trial found no significant difference in adherence between individual patient education and control.
Intensified patient care (eight studies)
All of the six studies that used direct patient contact intervention showed a significant positive effect on adherence. Of the five studies that used telephone or telemonitoring programmes, only one led to increased adherence.
Complex behavioural approaches (two studies)
Two trials found no significant effect of complex behavioural interventions on medication adherence.
Simplification of the drug regimen (one study)
One trial found no evidence of enhanced adherence following the simplification of the drug regimen.