title: Mini-Cog and Mini-Mental State Examination: agreement in a cross-sectional study with an elderly sample.
abstract: OBJECTIVE
  We aimed to compare the Mini-Mental State Examination (MMSE) with the Mini-Cog, measuring agreement in participants' classification, using a general population sample.
  
  
  METHODS
  Cross-sectional evaluation of 609 community dwellers aged ≥60 years was performed by trained interviewers. Cohen's kappa and 95% confidence intervals (CI) were calculated to assess overall agreement, and Cronbach alphas computed to assess reliability. Two-parameter Item Response Theory models (difficulty and discrimination parameters) were used to assess discrimination.
  
  
  RESULTS
  Considering MMSE cut-point for scores <24, 3.1% of the participants would be 'cognitive impaired' and 6.2% considering cut-point scores <25. Following Mini-Cog's cut-point score <3, 11.3% would be impaired. For MMSE cut-point <24 and Mini-Cog <3, we observed a Cohen's kappa of 0.116 (95% CI: -0.073 to 0.305), and of 0.258 (95% CI: 0.101-0.415) for cut-point <25. The highest kappa was obtained for cut-point <26 on the MMSE and Mini-Cog <3 (kappa = 0.413). MMSE Cronbach alpha was 0.6108 and Mini-Cog's alpha was 0.2776. Co-calibration according to inherent ability is graphically presented.
  
  
  CONCLUSIONS
  Agreement between scales seems fragile in our sample. The discriminative and reliability analysis suggests a better performance for subsets of the MMSE compared with the Mini-Cog. Usefulness of calibrated scores is discussed.
authors.affiliation: Institute of Public Health of the University of Porto, Department of Clinical Epidemiology, Predictive Medicine and Public Health, University of Porto Medical School, Rua das Taipas 135–139, Porto, Portugal. dmcosta@med.up.pt
authors.forename: Diogo
authors.initials: D
authors.lastname: Costa
authors.forename: Milton
authors.initials: M
authors.lastname: Severo
authors.forename: Sílvia
authors.initials: S
authors.lastname: Fraga
authors.forename: Henrique
authors.initials: H
authors.lastname: Barros
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology / Q000523:psychology; D056344:Executive Function; D005260:Female; D016330:Frail Elderly / Q000523:psychology; D015577:Geriatric Assessment / Q000379:methods; D006801:Humans; D007361:Intelligence Tests / Q000592:standards / Q000706:statistics & numerical data; D007406:Interview, Psychological; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis* / Q000209:etiology / Q000523:psychology; D016743:Mental Competency; D011939:Mental Recall; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000592:standards / Q000706:statistics & numerical data; D011594:Psychometrics / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data; D011897:Random Allocation; D015203:Reproducibility of Results; D012307:Risk Factors