--- title: "Expression of Concern over MMAS-8 use in study of medication adherence in older adults with type 2" id: "plos-one-12-expression-of-concern-determinants-of-medication-adherence-among-older-adults" canonical_url: "https://medichelpline.com/clinical-feed/plos-one-12-expression-of-concern-determinants-of-medication-adherence-among-older-adults" content_type: "clinical_feed_article" specialty: "Endocrinology" source_name: "PLOS ONE (Medicine)" source_url: "https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0357069" published_at: "2026-08-27T14:00:00.000Z" evidence_level: "Journal Feed" license: "CC-BY-NC-4.0 / Informational Use" --- # Expression of Concern over MMAS-8 use in study of medication adherence in older adults with type 2 ## Provenance & Clinical Metadata - **Canonical URL:** https://medichelpline.com/clinical-feed/plos-one-12-expression-of-concern-determinants-of-medication-adherence-among-older-adults - **Specialty:** [Endocrinology](https://medichelpline.com/clinical-feed/endocrinology.md) - **Primary Source:** PLOS ONE (Medicine) - **Source URL:** [Original Journal Publication](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0357069) - **Published At:** 2026-08-27T14:00:00.000Z - **Evidence Rating:** Journal Feed ## Executive GIST (TL;DR) - An Expression of Concern was published by the PLOS One Editors on August 27, 2026 regarding a 2025 cross-sectional study on determinants of **medication adherence** among older adults with type 2 diabetes that used the **MMAS-8** instrument. - Concerns center on the use of the Morisky Medication Adherence Scale-8 (MMAS-8). The original MMAS-8 validation paper cited by the study was later retracted because of issues raised about the reported sensitivity and specificity. - The corresponding author told the editors they used a validated Persian version of the **MMAS-8**, citing an independent validation (Persian MMAS-8 validation in Iranian hypertensive patients) that reports its own sensitivity and specificity values. - The corresponding author also stated the 2025 study did not assess or rely on the sensitivity, specificity, predictive validity, or screening accuracy reported in the now-retracted 2008 MMAS-8 paper. - The PLOS One Editors issued the Expression of Concern to notify readers of the instrument-related issue and to advise that findings based on MMAS-8 adherence classifications in the 2025 article should be interpreted with caution. - Key bibliographic items cited in the Expression of Concern include: the 2025 PLoS One article by Mohammadi et al., the retracted 2008 Morisky et al. MMAS-8 validation, a 2023 retraction statement, and a 2015 Persian MMAS-8 validation paper by Moharamzad et al. - The editors did not report additional methodological flaws or changes to the study results; their notice is limited to instrument-related concerns and the recommendation for cautious interpretation. ## Clinical Analysis & Structured Key Points Expression of Concern: Determinants of medication adherence among older adults with type 2 diabetes using the health action process approach: A cross-sectional study | PLOS One Browse Subject Areas ? Click through the PLOS taxonomy to find articles in your field. For more information about PLOS Subject Areas, click here . Article Metrics Comments Media Coverage Reader Comments After this article [ 1 ] was published, concerns were noted regarding its use of the Morisky Medication Adherence Scale-8 (MMAS-8), published in [ 2 ], which was retracted due to concerns regarding the reported specificity and sensitivity values [ 3 ]. The corresponding author stated that they used the validated Persian version of MMAS-8 [ 4 ], cited in [ 1 ] as Reference 24, which independently reports sensitivity and specificity values. They further stated that [ 1 ] does not assess or rely upon the sensitivity, specificity, predictive validity, or screening accuracy reported in [ 2 ]. The PLOS One Editors issue this Expression of Concern to inform readers of the above issue and to advise that findings in [ 1 ] based on MMAS-8 adherence classifications should be interpreted with caution. References 1. Mohammadi S, Khorami B, Seyedtabib M, Najafpour Z. Determinants of medication adherence among older adults with type 2 diabetes using the health action process approach: A cross-sectional study. PLoS One. 2025;20(9):e0332235. pmid:40997074 View Article PubMed/NCBI Google Scholar 2. Morisky DE, Ang A, Krousel-Wood M, Ward HJ. Retracted: Predictive validity of a medication adherence measure in an outpatient setting. J Clin Hypertens (Greenwich). 2008;10(5):348–54. pmid:18453793 View Article PubMed/NCBI Google Scholar 3. Retraction statement: Predictive validity of a medication adherence measure in an outpatient setting. J Clin Hypertens. 2023;25:889–889. View Article Google Scholar 4. Moharamzad Y, Saadat H, Nakhjavan Shahraki B, Rai A, Saadat Z, Aerab-Sheibani H, et al. Validation of the Persian Version of the 8-Item Morisky Medication Adherence Scale (MMAS-8) in Iranian Hypertensive Patients. Glob J Health Sci. 2015;7(4):173–83. pmid:25946926 View Article PubMed/NCBI Google Scholar Citation: The PLOS One Editors (2026) Expression of Concern: Determinants of medication adherence among older adults with type 2 diabetes using the health action process approach: A cross-sectional study. PLoS One 21(8): e0357069. https://doi.org/10.1371/journal.pone.0357069 Published: August 27, 2026 Copyright: © 2026 The PLOS One Editors. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 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