Studies Using the Medication Adherence Report Scale (MARS)
The Medication Adherence Report Scale (MARS) has been used in numerous studies across multiple disease conditions to assess patient adherence to medication regimens, with validated versions in multiple languages showing good reliability and validity.
Overview of MARS Versions and Validation
The MARS exists in multiple versions, with MARS-5 being one of the most commonly used:
- MARS-5: A 5-item version that demonstrates acceptable reliability (Cronbach's alpha 0.67-0.89) and validity across multiple patient populations 1
- MARS-D: German translation with satisfactory internal consistency (Cronbach's alpha 0.60-0.69) and test-retest reliability (r=0.61-0.63) 2
- MARS Arabic version: Validated through factor analysis with good internal consistency (Cronbach's alpha 0.89-0.93) 3
- MARS for psychosis: 10-item version specifically for patients with psychosis, showing moderate to weak concurrent validity with clinician ratings 4
Disease Conditions Where MARS Has Been Used
MARS has been validated and used across numerous chronic conditions:
- Hypertension: Shows criterion-related validity with blood pressure control (better adherence correlates with better BP control) 1
- Diabetes: Used to assess adherence in diabetic patients 1
- Asthma: Validated for use in respiratory conditions 1
- Psychosis/Schizophrenia: 10-item version specifically developed and validated 4
- Multiple chronic conditions: The MAR-Scale (Medication Adherence Reasons Scale), a related 20-item comprehensive scale, has been validated across 17 distinct chronic disease conditions including multiple sclerosis (Cronbach's alpha 0.861) and psoriasis (Cronbach's alpha 0.973) 5
Key Features of MARS as a Measurement Tool
MARS offers several advantages as a medication adherence assessment tool:
- Self-reported measure: Provides patient perspective on medication-taking behavior
- Brevity: The 5-item version (MARS-5) is quick to administer
- Psychometric properties: Shows acceptable internal reliability and test-retest reliability
- Construct validity: Demonstrates relationship with beliefs about medicines, with higher adherence associated with stronger beliefs in treatment necessity and lower treatment concerns 1
Methodological Considerations When Using MARS
When using MARS in research, several methodological considerations should be noted:
- Reporting consistency: The European Society for Patient Adherence (ESPACOMP) developed the ESPACOMP Medication Adherence Reporting Guideline (EMERGE) to standardize reporting of medication adherence research 6
- Adherence phases: Consider which phase of adherence (initiation, implementation, persistence) is being measured 6
- Triangulation: Using multiple methods to capture adherence provides more reliable estimates than single methods 6
- Patient characteristics: Socio-demographic characteristics may influence MARS scores, with higher reported adherence for older patients and those taking more medications 2
Common Reasons for Non-Adherence Identified Using MARS
Studies using MARS and related scales have identified common reasons for non-adherence across conditions:
- "Simply missed it" (forgetfulness)
- Concerns about side effects
- Concerns about long-term effects of medications 5
MARS provides researchers and clinicians with a validated tool to identify these barriers to adherence, which can then be targeted through interventions.