Validation of the 5-Item Medication Adherence Report Scale in Older Stroke Patients in Iran

Abstract

Background: There is a lack of feasible and validated measures to self-assess medication adherence for older patients with stroke. In addition, the potential determinants of medication adherence for older patients with stroke remain unclear. Objectives: The aims of this study were to (1) examine the psychometric properties of a 5-item questionnaire on medication adherence, specifically the 5-item Medication Adherence Report Scale (MARS-5), and (2) explore the determinants of medication adherence. Methods: Stroke patients older than 65 years (N = 523) filled out the MARS-5 and the Hospital Anxiety and Depression Scale. The medication possession rate (MPR) was calculated to measure the objective medication adherence. Several clinical characteristics (stroke types, blood pressure, comorbidity, HbA1c, quantity of prescribed drugs, fasting blood glucose, and total cholesterol) and background information were collected. We used Rasch analysis with a differential item functioning test to examine psychometric properties. Results: All 5 items in the MARS-5 fit in the same construct (ie, medication adherence), no differential item functioning items were displayed in the MARS-5 across gender, and the MARS-5 total score was strongly correlated with the MPR (r = 0.7). Multiple regression models showed that the MARS-5 and the MPR shared several similar determinants. In addition, the variance of the MARS-5 (R 2 = 0.567) was more than that of the MPR (R 2 = 0.300). Conclusions: The MARS-5 is a feasible and

Modifiable Factors Associated with Non-adherence to Antihypertensive or Antihyperlipidemic Drugs Are Dissimilar: a Multicenter Study Among Patients with Diabetes in Indonesia

“…The MARS scale has been shown to correlate well with other indirect methods, including pill counts among patients with hypertension and refill rates (using medication possession ratio) among patients with stroke. 43,44 Furthermore, the subtype analyses sometimes included small numbers leading to wide confidence intervals and loss of power. Due to the cross-sectional design, no causal inferences can be made regarding the temporal association between medication beliefs and non-adherence.…”

Effectiveness of a Patient-Tailored, Pharmacist-Led Intervention Program to Enhance Adherence to Antihypertensive Medication: The CATI Study

“…An explanation for these inconsistent results could be the use of pharmacy refill data as reference standard, since this measures another underlying construct compared to self-reported questionnaires. However, a large number of studies have shown acceptable validity and reliability of MARS-5 and therefore we have chosen this measure for this study ( Cohen et al, 2009 ; Mora et al, 2011 ; Bäck et al, 2012 ; Salt et al, 2012 ; Horne, 2013 ; Lin et al, 2018 ). The chosen cut-off value for MARS-5 might be a plausible explanation for the absence of effects.…”

“…The MARS-5 sum score was also dichotomized, where a score below 25 points indicates non-adherence. The MARS-5 questionnaire is an easy-to-use tool and shows acceptable reliability and validity ( Horne et al, 2001 ; Cohen et al, 2009 ; Mora et al, 2011 ; Bäck et al, 2012 ; Salt et al, 2012 ; Horne, 2013 ; Lin et al, 2018 ).…”

Smartphone Application-Based Addiction Among Iranian Adolescents: A Psychometric Study

“…Differential item functioning (DIF) was further computed in the Rasch model to test the measurement invariance of the SABAS across subgroups at the item level. More specifically, if the subgroup is gender, DIF can clearly identify which item content for males as compared with females are easier or harder to achieve (Lin et al 2018b, c). The suggested cutoff of DIF is < 0.5 in the DIF contrast (i.e., the difference of difficulty between two subgroups) (Lin et al 2018b, c).…”