Scale Analysis

The Morisky Medication Adherence Scale (MMAS-8) was developed in 2008 by Dr. Morisky and is an evolution of an earlier reliable scale (MMAS-4, 1986), which was used to assess adherence to prescribed medication regimens.

Objective

The questions in the questionnaire relate to the degree of the patient’s adherence to the medication regimen prescribed by their physician and concern the consistency of the patient’s medication-taking behavior.

Question Scoring

The Morisky Medication Adherence Scale consists of 8 items. The first 7 questions are answered with a yes/no response, except for the last one, which is answered using a 5-point Likert scale.

Statistical Analysis

To minimize response bias (i.e., patients’ tendency to answer positively to all questions), some of the eight questions are phrased in a reverse format. For questions 1 to 7, a “no” response is scored as 1 point and a “yes” as 0 points, except for question 5, where “no” is scored as 0 and “yes” as 1.
Regarding the final question, “Almost never” is scored with 1 point, while “Almost always” is scored with 0 points. The answer “Rarely” scores 0.75, “Sometimes” scores 0.5, and “Often” scores 0.25.
Therefore, a total score is derived, ranging from 0 to 8. For scores less than 6, adherence is considered low. For scores from 6 to less than 8, adherence is medium. A score of exactly 8 indicates high adherence.

Validity and Reliability

The wide international use of the scale sparked interest in translating the MMAS-8 into Greek by Plakas, Mastrogiannis, Mantzorou, Adamakidou, Fouka, Bouziou, and Tsiou. The translated version was compared with the one issued by the MAPI Institute and was found to be equivalent and approved by the scale’s owner.
The original MMAS-8 study showed high internal consistency reliability with a Cronbach’s alpha of 0.83, while the Greek version study showed satisfactory reliability with a Cronbach’s alpha of 0.75. The MMAS has been validated for use in many countries with various patient groups and has been shown to be a valid and reliable scale for measuring medication adherence.

References

Author: Morisky D.E.
Greek adaptation: Plakas, S., Mastrogiannis, D., Mantzorou, M., Adamakidou, T., Fouka, G., Bouziou, A., and Tsiou, C.
Keywords: Morisky Medication Adherence Scale, MMAS-8, Medication, Drug Adherence, Behavior, Dependence, Scale Analysis.