title: Clock drawing test - screening utility for mild cognitive impairment according to different scoring systems: results of the Leipzig Longitudinal Study of the Aged (LEILA 75+).
abstract: BACKGROUND
  There is a strong demand for screening instruments for mild cognitive impairment (MCI), as a pre-stage of dementia. The clock drawing test (CDT) is widely used to screen for dementia, but the utility in screening for MCI remains uncertain. In particular, it is still questionable which scoring system is the best in order to screen for MCI. We therefore aimed to compare the utility of different CDT scoring systems for screening for MCI.
  
  
  METHODS
  In a sample of 428 subjects of the Leipzig Longitudinal Study of the Aged (LEILA 75+) study, CDT scores of different scoring systems were compared between subjects with and without MCI. Comparison of receiver operating characteristic (ROC; area under the curve, sensitivity, specificity) was performed and inter-rater reliability was calculated.
  
  
  RESULTS
  The CDT scores differed significantly between MCI and non-MCI subjects according to all scoring systems applied. However, ROC of the CDT scores was not adequate.
  
  
  CONCLUSIONS
  None of the present CDT scoring systems has sufficient utility to screen reliably for MCI. The clinical value of the CDT could be improved by using semi-quantitative scoring, having a wider score range and focusing on specific details of the clock (e.g. the hands and numbers).
authors.affiliation: Institute of Social Medicine, Occupational Health and Public Health, University of Leipzig, Leipzig, Germany. Lena.Ehreke@medizin.uni-leipzig.de
authors.forename: Lena
authors.initials: L
authors.lastname: Ehreke
authors.forename: Tobias
authors.initials: T
authors.lastname: Luck
authors.forename: Melanie
authors.initials: M
authors.lastname: Luppa
authors.forename: Hans-Helmut
authors.initials: HH
authors.lastname: König
authors.forename: Arno
authors.initials: A
authors.lastname: Villringer
authors.forename: Steffi G
authors.initials: SG
authors.lastname: Riedel-Heller
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000523:psychology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009483:Neuropsychological Tests / Q000592:standards* / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D012720:Severity of Illness Index