title: Reliability and validity of a self-reported measure of medication adherence in patients with type 2 diabetes mellitus in Korea.
abstract: OBJECTIVE
  This study examined the psychometric properties of the Korean version of the eight-item Morisky Medication Adherence Scale (MMAS-8) to measure adherence to diabetes medication in patients with type 2 diabetes mellitus.
  
  
  METHODS
  The English version of the MMAS-8 was translated into Korean and administered to patient with type 2 diabetes mellitus via face-to-face interviews, conducted by an independent interviewer. Patient characteristics and glycosylated haemoglobin (HbA1c) levels were assessed at the same clinic visit. A proportion of patients was randomly selected for 2-week test-retest reliability via telephone interviews. Convergent validity of the MMAS-8 against a four-item MMAS, correlations with HbA1c levels and construct validity of the MMAS-8 were evaluated.
  
  
  RESULTS
  In total, 317 patients were included; 70 completed the 2-week test-retest interview. Internal consistency reliability was moderate and test-retest reliability of the MMAS-8 was excellent, although a ceiling effect was detected. Good convergent validity was shown by the high correlation of the new scale scores with the original MMAS-4. A significant association was found between MMAS-8 scores and HbA1c levels. Using glycaemic control as a gold standard, sensitivity was 74.1% and specificity was 38.3%. Explanatory factor analysis identified three dimensions of the scale.
  
  
  CONCLUSIONS
  In light of acceptable reliability and validity, the MMAS-8 is a simple and quick method for the assessment of medication adherence among patient with type 2 diabetes mellitus, in a busy clinic setting.
authors.affiliation: Department of Preventive Medicine, College of Medicine, Chung-Ang University, Seoul, Republic of Korea.
authors.forename: Weon-Young
authors.initials: WY
authors.lastname: Lee
authors.forename: Jihyun
authors.initials: J
authors.lastname: Ahn
authors.forename: Jeung-Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Yeon-Pyo
authors.initials: YP
authors.lastname: Hong
authors.forename: Seung Kwon
authors.initials: SK
authors.lastname: Hong
authors.forename: Young Taek
authors.initials: YT
authors.lastname: Kim
authors.forename: Seok Hong
authors.initials: SH
authors.lastname: Lee
authors.forename: Donald E
authors.initials: DE
authors.lastname: Morisky
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000523:psychology*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D008297:Male; D055118:Medication Adherence / Q000208:ethnology / Q000523:psychology; D008875:Middle Aged; D011594:Psychometrics / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D056910:Republic of Korea; D012107:Research Design; D057566:Self Report; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires; D016903:Drug Monitoring
chemical_list: D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents
keywords: Eight-item Morisky Medication Adherence Scale; MMAS-8; medication adherence; psychometrics; self-report questionnaire; type 2 diabetes mellitus