Analyzing the effects of barriers to and facilitators of medication adherence among patients with cardiometabolic diseases: a structural equation modeling approach

Katharina Quaschning; Mirjam Koerner; Markus Antonius Wirtz

doi:10.1186/s12913-022-07987-3

Analyzing the effects of barriers to and facilitators of medication adherence among patients with cardiometabolic diseases: a structural equation modeling approach

BMC Health Serv Res. 2022 May 2;22(1):588. doi: 10.1186/s12913-022-07987-3.

Authors

Katharina Quaschning¹, Mirjam Koerner², Markus Antonius Wirtz³

Affiliations

¹ Institute of Medical Psychology and Medical Sociology, Faculty of Medicine, University of Freiburg, Hebelstraße 29, 79104, Freiburg, Germany. katharina.quaschning@mps.uni-freiburg.de.
² Institute of Medical Psychology and Medical Sociology, Faculty of Medicine, University of Freiburg, Hebelstraße 29, 79104, Freiburg, Germany.
³ Department of Research Methods in the Health Sciences, Institute of Everyday Culture, Sports and Health, University of Education Freiburg, Kunzenweg 21, 79117, Freiburg, Germany.

Abstract

Background: Based on the theoretical model of medication adherence (WHO, 2003), the aims of the study were (1) to develop and test a theory-based multidimensional model for the predictive power of barriers to and facilitators of medication adherence and (2) to identify the mediating effects of barriers to medication adherence on drug-related patient outcomes (barrier "MedAd- ": forget; facilitator "MedAd + ": regular intake).

Methods: Within a cross-sectional study entitled "Increasing medication adherence to improve patient safety in cardiological rehabilitation (PaSiMed)", the model was evaluated in structural analytical terms based on data collected online of N = 225 patients with cardiometabolic diseases. The revised "Freiburg questionnaire on medication adherence (FF-MedAd-R)" was used to measure the latent constructs (e.g., facilitator: communication; barrier: reservations)."

Results: The structural equation model proved to exhibit an appropriate data fit (RMSEA: .05; CFI: .92). For all first-order facilitators of medication adherence, a high proportion of variance (62-94%) could be explained by the second-order factor "Physician-patient relationship (PPR)". All paths from "PPR" to the constructs depicting barriers to medication adherence showed significant negative effects. Facilitators ("MedAd + ") and barriers ("MedAd-") accounted for 20% and 12% of the variance, respectively, in global items of medication adherence. Whereas "Carelessness" showed a full mediation for "MedAd-", ''Reservations'' showed a partial mediation for "MedAd + ".

Conclusions: "PPR" is an important predictor of patient medication adherence. The results underline the importance of a trustful physician-patient relationship in reducing barriers and enhancing medication adherence.

Keywords: Diabetes mellitus; Hypertension; Medication adherence; Questionnaire; Structural equation model.

MeSH terms

Cardiovascular Diseases* / drug therapy
Cross-Sectional Studies
Humans
Latent Class Analysis
Medication Adherence*
Surveys and Questionnaires