Personal characteristics and the law of attrition in randomized controlled trials of eHealth services for self-care

Despite its evident advantages, applying a Randomized Controlled Trial (RCT) to evaluate Information and Communication Technology services for self-care (i.e., eHealth) may have limitations. For medical intervention research, an RCT is generally considered the 'gold standard' and could well be used for empirical research of eHealth 1 . RCTs determine whether a cause-effect relationship exists between an intervention and an outcome, as well as assessing the cost effectiveness of the intervention. Accordingly, findings in the experimental setting can be directly translated into implications for health care contexts. However, these trials often face a high dropout rate of participants. The phenomenon of recurring high dropout rates across RCTs evaluating eHealth services is referred to as Eysenbach's 'Law of Attrition' 2 . The Law of Attrition occurs in non-technical RCTs Such services enable individuals to make decisions and perform activities together with families, and communities to prevent disease, limit illness, and restore health at home 5 .