Oſten, compliance is also used and the two can be used interchangeably in research and clinical practice . It describes “the extent to which the patients’ behavior (including medication-taking) coincides with medical or healthcare advice”, yet its meaning has become more negative regarding patient’s behaviors, since it implies patient’s passivity.
Nevertheless,measurement of medication adherence can be quite challenging since and parameters of acceptable adherence need to be carefully delineated and appropriated for individual situations. There are numerous tools available for these measurements, but these need to prove to be valid, reliable, and sensitive to change. The selection of a method to monitor adherence should be based on individual attributes and goals/resources of the study or the clinical setting. Currently none of the available methods can be considered as a gold standard and the combination of methods is recommended.
Objective measures include pill counts, electronic monitoring, secondary database analysis and biochemical measures and are thought to represent an improvement over subjective measures. As such, objective measures should be used to validate and correlate the subjective ones. However, a meta-analysis on adherence outcomes states that a multi-subjective-measure approach may have higher sensitivity, but not accuracy, over employing a single objective measure. In summary, subjective and objective measures have both advantages and disadvantages and should be used in combination.
The Medication Events Monitoring System (MEMS) is the most commonly used EMP device in medication adherence studies.
Studies show that approxi- mately 25% of all prescribed doses are omitted by patients.
This was in 1999 more recent studies say 50% are non adherent. like the study below:
Who. Defining adherence. Who. 2003;:1–28. www.who.int/chp/knowledge/publications/adherence_report/en/?
No single intervention is totally effective for all patients and it is not yet possible to predict which individual or subgroup actually needs a given intervention.
Patients also are reluctant to admit non-adherence unless clinicians make specific efforts to monitor the degree of adherence on a regular basis.
Studies have demonstrated that MEMS is more accurate than other available methods and is therefore considered the ‘‘gold standard’’ of adherence measurement. Despite these advantages, this tool has not yet been applied widely due to its cost and other practical issues that limit its use in large studies and routine clinical practice.[Top]