Measuring adherence to medical treatments in childhood chronic illness: Considering multiple methods and sources of information

Adherence to medical treatment is a significant problem for children and adolescents with chronic conditions, such as asthma, diabetes, and cystic fibrosis. The consequences of nonadherence can be serious, contributing to increased symptoms, unnecessary hospitalizations, and declines in physical functioning. The quality of data obtained from clinical trials can also be affected by poor adherence, leading to erroneous conclusions concerning the efficacy of drug treatments and the dosages that are needed to achieve those effects. Adherence problems in both clinical research and practice also lead to substantially higher health care costs. In order to further our understanding of the barriers that lead to poor adherence and identify strategies that are effective in addressing them, we need to develop reliable and valid measures of adherence behaviors. Using cystic fibrosis as a model of a serious, chronic disease that requires a difficult and time-consuming medical regimen, three different types of adherence measures are considered: self-report questionnaires, daily diary reports, and electronic monitors. The specific advantages and disadvantages of each type of measurement are reviewed, and specific recommendations are made for future research.