Seventy-one RCTs were included. The authors noted that many of the studies used routine medical care as the comparator, which potentially led to confounding between the amount of contact and the e-intervention and an overestimation of the effectiveness of the e-intervention.
Mental health interventions (11 RCTs): There was an overall positive pattern of results for web-based interventions for mental health conditions; six out of seven psychoeducational interventions for people with mental health conditions reported statistically significant benefit on all or most outcomes compared to control and one did not. All four telephone-based showed positive benefits on mental health outcomes.
Diabetes interventions (14 RCTs): Six of seven web-based interventions showed positive effects on a range of behavioural, psychosocial and biological measures. Two of the seven studies of telephone-based interventions reported statistically significant improvement in the intervention group compared to control and the other five studies did not. The authors noted that the short duration of the interventions, inclusion of participants with disadvantaged and disrupted living conditions and severe illness may have been contributing factors in the lack of benefit.
Cardiac conditions (12 RCTs): Seven of the 11 studies that used a telephone-based intervention reported a positive benefit compared to control and four studies did not. Improvements included reduced hospitalisation. In the single web-based study there were fewer cardiovascular events and greater weight loss in the intervention than in the control group.
Other conditions: Twenty-eight RCTs assessed interventions in a range of different conditions. Only studies that related to pulmonary conditions, cancer and chronic pain were discussed. Most studies reported positive improvements with the e-interventions.