The contributions in this section deal with measurement issues in treatment adherence in childhood chronic illness, focusing on asthma and diabetes as key examples. In her comprehensive overview of treatment adherence in pediatric illness in chapter 6, Matsui underscores the need to identify the specific type of noncompliance, such as delayed or omitted doses, taking the wrong amount of medication, improper dosage intervals, taking the wrong medication, and premature discontinuation. Matsui points out that, although most studies of compliance are focused on whether patients consume medications that are available to them, it is important to determine whether patients actually fill their prescriptions because patients cannot take medications that they do not have.
Matsui also considers the advantages and disadvantages of available methods that can be used in the assessment of medication compliance such as self-report measures, pill counts, and direct measurement of drug levels and bodily fluids, such as blood or urine--microelectronic devices. Another important measurement issue noted by Matsui is the importance of assessing compliance in explaining treatment failure and targeting patients for more intensive interventions. One of Matsui's contributions is to consider the impact of noncompliance on measurement, clinical assessment, and decision making. For example, discovering the potential impact of poor compliance in a clinical trial of a new drug may result in a potentially beneficial medication being abandoned due to its apparent lack of efficacy. Another consequence is that medical decisions may be affected by