title: Diagnostic performance of an Executive Clock Drawing Task (CLOX) as a screening test for mild cognitive impairment in elderly persons with cognitive complaints.
abstract: BACKGROUND
  CLOX, a clock drawing test protocol uniquely sensitive to impairment of executive functions, has been proposed as a screening tool for mild cognitive impairment (MCI), but data about its diagnostic efficiency are lacking.
  
  
  METHODS
  There are data for 196 subjects, age >or=60 years, referred to a memory clinic for cognitive complaints. After extensive neuropsychological testing, 64 were diagnosed as cognitively normal and 132 with MCI.
  
  
  RESULTS
  At standard cutoffs, both CLOX subtests had a fair specificity (CLOX1 72%, CLOX2 92%) but unacceptably low values of sensitivity (CLOX1 54%, CLOX2 28%) and likelihood ratio (CLOX1 1.91, CLOX2 3.59) for MCI. The use of different cutoffs or the combination of CLOX with the Mini-Mental State Examination (MMSE) did not statistically increase diagnostic efficiency.
  
  
  CONCLUSIONS
  CLOX, either alone or in combination with MMSE, is not a useful screening test for MCI in a clinical setting.
authors.affiliation: Department of Internal Medicine, Ageing, and Nephrology, University Hospital St. Orsola-Malpighi, University of Bologna, Bologna, Italy. paola.forti@unibo.it
authors.forename: Paola
authors.initials: P
authors.lastname: Forti
authors.forename: Valentina
authors.initials: V
authors.lastname: Olivelli
authors.forename: Elisa
authors.initials: E
authors.lastname: Rietti
authors.forename: Benedetta
authors.initials: B
authors.lastname: Maltoni
authors.forename: Giovanni
authors.initials: G
authors.lastname: Ravaglia
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology*; D003863:Depression / Q000523:psychology; D004493:Education; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D012372:ROC Curve