title: Validation of conversion between mini-mental state examination and montreal cognitive assessment.
abstract: BACKGROUND
  Harmonizing data across cohorts is important for validating findings or combining data in meta-analyses. We replicate and validate a previous conversion of MoCA to MMSE in PD.
  
  
  METHODS
  We used five studies with 1,161 PD individuals and 2,091 observations measured with both the MoCA and MMSE. We compared a previously published conversion table using equipercentile equating with log-linear smoothing to our internally derived scores.
  
  
  RESULTS
  Both conversions found good agreement within and across the studies when comparing true and converted MMSE (mean difference: 0.05; standard deviation: 1.84; median difference: 0; interquartile range: -1 to 1, using internal conversion).
  
  
  CONCLUSIONS
  These results show that one can get a reliable and valid conversion between two commonly used measures of cognition in PD studies. These approaches need to be applied to other scales and domains to enable large-scale collaborative analyses across multiple PD cohorts.
authors: School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
authors: Michael
authors: M
authors: Lawton
authors: Department of Psychiatry and Psychotherapy and Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.
authors: Meike
authors: M
authors: Kasten
authors: School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
authors: Margaret T
authors: MT
authors: May
authors: Paracelsus-Elena-Klink, Kassel, Germany.|Departments of Neurosurgery and Neuropathology, University Medical Center Göttingen, Germany.
authors: Brit
authors: B
authors: Mollenhauer
authors: Paracelsus-Elena-Klink, Kassel, Germany.
authors: Martina
authors: M
authors: Schaumburg
authors: German Center for Neurodegenerative Diseases (DZNE), Tuebingen, Germany.
authors: Inga
authors: I
authors: Liepelt-Scarfone
authors: German Center for Neurodegenerative Diseases (DZNE), Tuebingen, Germany.|Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tuebingen, Tuebingen, Germany.
authors: Walter
authors: W
authors: Maetzler
authors: Department of Psychiatry and Psychotherapy and Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.
authors: Eva-Juliane
authors: EJ
authors: Vollstedt
authors: Nuffield Department of Clinical Neurosciences, Division of Clinical Neurology, University of Oxford, United Kingdom.|Oxford Parkinson's Disease Center, University of Oxford, Oxford, United Kingdom.
authors: Michele T M
authors: MT
authors: Hu
authors: German Center for Neurodegenerative Diseases (DZNE), Tuebingen, Germany.|Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tuebingen, Tuebingen, Germany.
authors: Daniela
authors: D
authors: Berg
authors: School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
authors: Yoav
authors: Y
authors: Ben-Shlomo
mesh_terms: D000368:Aged; D015331:Cohort Studies; D006801:Humans; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D010300:Parkinson Disease / Q000175:diagnosis*; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data*; D011594:Psychometrics / Q000592:standards*
keywords: Mini-Mental State Examination; Montreal Cognitive Assessment; Parkinson's disease; equating