This 5-items scale asks respondents to rate the frequency with which they engage in each of 5 aspects of non-adherent behaviour Eg deciding to miss a dose, forgetting to take a dose), rated on a five point scale (where 5=never, 4 = rarely, 3 = sometimes, 2 = often and 1= very often). Scores for each of the 5 items were summed to give a scale score ranging from 5 to 25, where higher scores indicate higher levels of reported adherence.
Adherence can be expressed as a continuous scale, or by separating into ‘high’ and ‘low’ adherence groups on the basis of scale scores.
The MARS-5 offers a convenient, ‘spot check’ estimate of adherence behaviour that can be used to grade patients according to their ‘relative standing on the adherence dimension’ rather than as an exact measure of when and how patients took their medicines.
The MARS attempts to diminish the social pressure on patients to underreport non-adherence by phrasing adherence questions in a non-threatening manner and assuring them that responses were anonymous and confidential, as recommended in the literature
Since 1996, the MARS has been used in research studies across arrange of illnesses and in several countries. A paper describing the validity and reliability testing of the scale has been submitted for publication