title: Validation of Malaysian Versions of Perceived Diabetes Self-Management Scale (PDSMS), Medication Understanding and Use Self-Efficacy Scale (MUSE) and 8-Morisky Medication Adherence Scale (MMAS-8) Using Partial Credit Rasch Model.
abstract: BACKGROUND
  The Diabetes Mellitus (DM) is a common silent epidemic disease with frequent morbidity and mortality. The psychological and psychosocial health factors are negatively influencing the glycaemic control in diabetic patients. Therefore, various questionnaires were developed to address the psychological and psychosocial well-being of the diabetic patients. Most of these questionnaires were first developed in English and then translated into different languages to make them useful for the local communities.
  
  
  OBJECTIVE
  The main aim of this study was to translate and validate the Malaysian versions of Perceived Diabetes Self-Management Scale (PDSMS), Medication Understanding and Use Self-Efficacy Scale (MUSE), and to revalidate 8-Morisky Medication Adherence Scale (MMAS-8) by Partial Credit Rasch Model (Modern Test Theory).
  
  
  METHODS
  Permission was obtained from respective authors to translate the English versions of PDSMS, MUSE and MMAS-8 into Malay language according to established standard international translation guidelines. In this cross-sectional study, 62 adult DM patients were recruited from Hospital Kuala Lumpur by purposive sampling method. The data were extracted from the self-administered questionnaires and entered manually in the Ministeps (Winsteps) software for Partial Credit Rasch Model. The item and person reliability, infit/outfit Z-Standard (ZSTD), infit/outfit Mean Square (MNSQ) and point measure correlation (PTMEA Corr) values were analysed for the reliability analyses and construct validation.
  
  
  RESULTS
  The Malay version of PDSMS, MUSE and MMAS-8 found to be valid and reliable instrument for the Malaysian diabetic adults. The instrument showed good overall reliability value of 0.76 and 0.93 for item and person reliability, respectively. The values of infit/outfit ZSTD, infit/outfit MNSQ, and PTMEA Corr were also within the stipulated range of the Rasch Model proving the valid item constructs of the questionnaire.
  
  
  CONCLUSIONS
  The translated Malay version of PDSMS, MUSE and MMAS-8 was found to be a highly reliable and valid questionnaire by Partial Credit Model. The Malay version was conceptually equivalent to original version, easy to understand and can be used for the Malaysian adult diabetic patients for future studies.
authors.affiliation: Clinical BioPharmaceutics Research Group (CBRG), Faculty of Pharmacy, Universiti Teknologi MARA , Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia .
authors.forename: Safaa Ahmed
authors.initials: SA
authors.lastname: Al Abboud
authors.affiliation: Faculty of Pharmacy, Level 9, Pharmacy Building, MAHSA University , Jalan SP2, Bandar Saujana Putra, 42610 Jenjarom, Kuala Langat, Selangor, Malaysia .
authors.forename: Sohail
authors.initials: S
authors.lastname: Ahmad
authors.affiliation: Endocrine Unit, Medical Department, Hospital Kuala Lumpur , 50586 Jalan Pahang, Kuala Lumpur, Malaysia .
authors.forename: Mohamed Badrulnizam Long
authors.initials: MB
authors.lastname: Bidin
authors.affiliation: Faculty of Pharmacy, Level 9, Pharmacy Building, MAHSA University , Jalan SP2, Bandar Saujana Putra, 42610 Jenjarom, Kuala Langat, Selangor, Malaysia .
authors.forename: Nahlah Elkudssiah
authors.initials: NE
authors.lastname: Ismail
keywords: Reliability; Type 2 diabetes mellitus; Validity