Related Experiment Video
Updated: Jun 3, 2026

Advancing Dyslexia Assessment in Children Through Computerized Testing
Published on: August 16, 2024
Factor structure and longitudinal invariance of the Medical Adherence Report Scale-Asthma
Pablo A Mora1, Alayna Berkowitz, Richard J Contrada
1Department of Psychology, University of Texas at Arlington, Arlington, TX, USA. pmora@uta.edu
Abstract:
Adequate assessment of adherence to medical treatment is critical for both research purposes and clinical practice. This study examined the factor structure and longitudinal invariance of the Medication Adherence Report Scale (MARS-A10) in a sample of asthmatic patients. We examined longitudinal data from 294 inner-city, adult participants with moderate to severe asthma. Because of ambiguous evidence regarding the dimensionality of the MARS-A10, the data was analysed with exploratory structural equation modelling. We first proceeded by determining the dimensionality of the scale at baseline and examined whether the structure, loadings, intercepts and errors were invariant over the four assessments points. Results indicated that a two-factor structure (factor 1: non-adherence based on experiential changes; factor 2: non-adherence based on intentional medication avoidance) had the best fit to the data (χ(2)(25)=37.69, p=0.05). Longitudinal analyses revealed that the nine items assessing intentional non-adherence were invariant over time. The evidence from the factor analysis suggests that intentional non-adherence is a multidimensional construct. Additionally, longitudinal data provided strong evidence that the items examining intentional non-adherence are invariant over time, indicating that changes in non-adherence scores can be validly attributed to changes in behaviour.
Related Concept Videos
Longitudinal Studies
Longitudinal Research
Asthma I: Introduction
Asthma III: Clinical Manifestations
Asthma-II: Pathophysiology and Classification
Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition.
Critical processes in asthma pathophysiology include:
Asthma-III: Symptoms and Complications
Classification of Asthma
