Department of Family Medicine
Medication Adherence Self-Efficacy Scale
Ogedegbe G, Mancuso CA, Allegrante JP, Charlson ME (2003)
Background and Development:
The purpose of the MASE scale is so clinicians and researchers can identify situations in which patients have low self-efficacy in adhering to prescribed medications. Open-ended interviews with 106 patients were used to elicit their experiences with taking antihypertensive medications. Using qualitative techniques, responses were recorded verbatim, coded, and sorted into nine categories of barriers and facilitators of medication adherence. Concepts from categories were formatted into an initial 43-item self-efficacy questionnaire, which was administered to another group of 72 patients for the item analyses phase. For each of the situations listed, patients are asked to rate how sure they are that they can take their blood pressure medications ALL OF THE TIME: Not at all sure, Somewhat sure, Very sure.
In all, 21 of the 43 items fulfilled the minimum item-to total correlation coefficient value of 0.5 and minimum kappa value of greater than 0.4. The remaining 22 items did not meet the selection criteria. Of these, five items were retained for their clinical significance. The five items retained reflected cost of medications, side effects, and frequency of dosing, all of which have been shown to be significant predictors of medication adherence. The Cronbach’s alpha for the entire 26-item scale was 0.95.
An exploratory principal components factor analysis performed on the 26 items of the final MASES revealed a five-factor solution using the minimum Eigen value criteria >1. These five factors accounted for about 93% of the total variance. Results of this factor analysis suggest that the final MASES is a one-dimensional scale, with the majority of the items loading on factor 1.
The mean self-efficacy score was 2.50 for all patients. Those with controlled blood pressure had higher mean self-efficacy score than those patients with uncontrolled blood pressure (2.54 vs. 2.48, P > 0.05). Although not statistically significant, this difference in mean self-efficacy score was in the predicted direction. This finding provides preliminary evidence for the inverse relationship between blood pressure and self-efficacy.
Assessment in Elderly Populations:
The initial subject population consisted of hypertensive patients ages 20 to 83 (mean age 56).
Assessment in Minority Populations:
The initial subject population consisted of hypertensive African-American patients (66% Women).
No other studies have used this scale.
Design Strengths and Weaknesses:
Internal reliability is excellent, however there is no external validation that results of the scoring equate with medication compliance or control of hypertension.
The initial 43 items and the final 26 items of the MASE are in tables in Ogedegbe et al. (2003).
Ogedegbe G, Mancuso CA, Allegrante JP, Charlson ME (2003) Development and evaluation of a medication adherence self-efficacy scale in hypertensive African-American patients. Journal of Clinical Epidemiology. 56(6):520-9.