Adherence In Clinical Study Procedure

Investigators conducting clinical trials need to appreciate the important role of adherence in clinical research. Poor compliance may reduce the power of a study and lead to an underestimation of the efficacy of a treatment and dismissal of a potentially useful therapeutic agent. In general, medication adherence of participants in clinical trials is better than in clinical practice. The study protocol should indicate how adherence will be handled, both in terms of measurement and in the data analysis. Unfortunately, no perfect method for assessing compliance exists, complicating research in this area. Techniques commonly employed in research include self-reporting (such as diaries), pill counts and electronic monitors with a combination of methods preferred. Selection of which method(s) to use will depend on the goals of the
One strategy to attempt to minimize the number of study subjects who will be poor adherers is to attempt to identify these individuals and eliminate them using a run-in period. Study participants should be well informed and expectations with respect to study procedures should be realistic. Factors that affect compliance should be considered in drug development to improve medication-taking behaviour. Drugs with less frequent dosing to enhance patient convenience or fixed-dose combination drugs to reduce the pill burden are possible options, as is the use of specialized containers and packaging.
Direct measures of adherence include drug assays of blood or urine, use of drug markers with the target medication, and direct observation of the patient receiving the medication. Indirect measures of adherence imply that the medication has been used by the patient; these measures include various forms of self-reporting by the patient, medication measurement (pill count), use of electronic monitoring devices, and review of prescription records and