12.3.4  Variation in adherence

Variation in the adherence of the recipients and providers of care can limit the applicability of results. Predictable differences in adherence can be due to divergence in economic conditions or attitudes that make some forms of care not accessible or not feasible in some settings, such as in developing countries (Dans 2007). It should not be assumed that high levels of adherence in closely monitored randomized trials will translate into similar levels of adherence in normal practice.