title: A Comparative Study of Tower of London Scoring Systems and Normative Data.
abstract: OBJECTIVE
  Tower of London (ToL) is a planning ability task that includes multiple versions. The original ToL was developed by Shallice together with two scoring systems (ToL-SS). Another two ToL-SS were proposed by Anderson et al. and Krikorian et al. The purpose of this study is to provide normative data for four ToL-SS and explore the effects of demographic variables on ToL performance. Furthermore, we aimed to determine the discriminative validity of these ToL-SS in clinical samples.
  
  
  METHODS
  Four groups were included in the study: a normative sample of healthy adults (HC; n = 298); patients with Parkinson's disease with mild cognitive impairment (PD-MCI; n = 52) and without cognitive impairment (PD-ND; n = 57); and patients with schizophrenia (SCH; n = 28). The effects of demographic variables on ToL-SS were examined in the HC group. Between-groups comparisons of ToL-SS were conducted using regression analysis with dummy codes.
  
  
  RESULTS
  All four ToL-SS were not significantly affected by age, whereas the effect of gender and education is not consistent. ToL-SS significantly (p < .05) differentiate HC from PD-MCI and SCH. Cohen's effect size coefficients d range from 0.68 to 1.29. Internal consistency coefficients (Cronbach's α) of ToL-SS range from 0.33 to 0.60.
  
  
  CONCLUSIONS
  Despite poor to questionable internal consistency of ToL-SS, the discriminative validity and clinical utility for assessing planning deficits in PD-MCI and SCH are high. This study provides normative standards for all four ToL-SS on an adult population for use in clinical practice.
authors.affiliation: Department of Psychiatry, First Faculty of Medicine and General University Hospital in Prague, Charles University in Prague, Prague, Czech Republic.
authors.forename: Jiri
authors.initials: J
authors.lastname: Michalec
authors.affiliation: Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine and General University Hospital in Prague, Charles University in Prague, Prague, Czech Republic.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Bezdicek
authors.affiliation: Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine and General University Hospital in Prague, Charles University in Prague, Prague, Czech Republic.
authors.forename: Tomas
authors.initials: T
authors.lastname: Nikolai
authors.affiliation: Department of Psychiatry, First Faculty of Medicine and General University Hospital in Prague, Charles University in Prague, Prague, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Harsa
authors.affiliation: Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine and General University Hospital in Prague, Charles University in Prague, Prague, Czech Republic.
authors.forename: Robert
authors.initials: R
authors.lastname: Jech
authors.affiliation: Department of Psychiatry, General University Hospital in Ostrava, Ostrava, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Silhan
authors.affiliation: Department of Psychiatry, General University Hospital in Ostrava, Ostrava, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Hyza
authors.affiliation: Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine and General University Hospital in Prague, Charles University in Prague, Prague, Czech Republic.
authors.forename: Evzen
authors.initials: E
authors.lastname: Ruzicka
authors.affiliation: Institute of Cognitive Neuroscience, University College London, London, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Shallice
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000209:etiology; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000592:standards / Q000706:statistics & numerical data*; D010300:Parkinson Disease / Q000150:complications*; D012016:Reference Values; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000150:complications*; D055815:Young Adult
keywords: Parkinson's disease mild cognitive impairment; Planning; Schizophrenia; Scoring; Tower of London