title: Sensitivity to change of composite and frequency scores of the Neuropsychiatric Inventory in mild to moderate dementia.
abstract: BACKGROUND
  The Neuropsychiatric Inventory (NPI) is widely used to assess psychopathology in dementia. The scoring involves ratings of frequency and severity, as well as the calculation of a composite score. It was suggested recently that, due to lower variance, the frequency score might be more sensitive to detect treatment-related change and to discriminate active treatment from placebo than the composite score, particularly in milder forms of the disease.
  
  
  METHODS
  Based on data from three randomized controlled trials in patients with mild to moderate dementia, standardized changes were calculated for both frequency and composite scores for two strata of disease severity. The two strata were formed by dichotomizing the sample along the median score of the short cognitive performance test (SKT) battery.
  
  
  RESULTS
  Across all studies and for both severity strata, standardized changes in frequency scores were not consistently larger than those in composite scores and both scores discriminated active treatment from placebo at similar probabilities for type-1 error.
  
  
  CONCLUSIONS
  Our findings do not support the notion that there is a difference between frequency score and composite score with respect to their sensitivity to treatment-related change.
authors.affiliation: Lou Ruvo Center for Brain Health, The Andrea L. and Joseph F. Hahn MD Chair of Neurotherapeutics, Cleveland Clinic, Las Vegas, NV, USA.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Cummings
authors.forename: Ralf
authors.initials: R
authors.lastname: Ihl
authors.forename: Horst
authors.initials: H
authors.lastname: Herrschaft
authors.forename: Robert
authors.initials: R
authors.lastname: Hoerr
authors.forename: Michael
authors.initials: M
authors.lastname: Tribanek
mesh_terms: D000368:Aged; D003704:Dementia / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology / Q000523:psychology*; D005260:Female; D020441:Ginkgo biloba; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D008517:Phytotherapy / Q000379:methods; D010936:Plant Extracts / Q000627:therapeutic use; D011569:Psychiatric Status Rating Scales; D011599:Psychopathology; D016032:Randomized Controlled Trials as Topic; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016896:Treatment Outcome; D000096983:Ginkgo Extract
chemical_list: D010936:Plant Extracts; C063170:Ginkgo biloba extract; D000096983:Ginkgo Extract