title: Greater than the Sum of Its Parts: δ can be Constructed from Item Level Data.
abstract: "δ", a latent variable constructed from cognitive performance and functional status measures, can accurately diagnose dementia. The minimal assessment needed is unknown. We have constructed a δ homolog, "dTEXAS", from Telephone Executive Assessment Scale (TEXAS) items, and validated it in a convenience sample of Japanese persons (n = 176). dTEXAS scores correlated strongly with both Instrumental Activities of Daily Living (IADL) (r = -0.86, p <  0.001) and Clinical Dementia Rating Scale (CDR) (r = 0.71, p <  0.001). Constructed independently of their diagnoses, dTEXAS scores accurately distinguished dementia versus controls (area under the receiver operating curve [(AUC; ROC) = 0.92], dementia versus mild cognitive impairment (MCI) (AUC = 0.80) and controls versus MCI (AUC = 0.74). These AUCs are higher than those of multiple observed executive measures, as reported recently by Matsuoka et al., 2014. A dTEXAS score of -0.58 best discriminated between dementia versus controls with 90.1% sensitivity and 80.0% specificity.
authors.affiliation: Department of Psychiatry, The University of Texas Health Science Center, San Antonio, TX, USA.|Department of Medicine, The University of Texas Health Science Center, San Antonio, TX, USA.|Department of Family and Community Medicine, The University of Texas Health Science Center, San Antonio, TX, USA.|South Texas Veterans' Health System, Audie L. Murphy Division GRECC, San Antonio, TX, USA.
authors.forename: Donald R
authors.initials: DR
authors.lastname: Royall
authors.affiliation: Department of Family and Community Medicine, The University of Texas Health Science Center, San Antonio, TX, USA.
authors.forename: Raymond F
authors.initials: RF
authors.lastname: Palmer
authors.affiliation: Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University School of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, Japan.
authors.forename: Teruyuki
authors.initials: T
authors.lastname: Matsuoka
authors.affiliation: Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University School of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Reinan Hospital, Mikatakaminakagun, Wakasacho, Fukui, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Taniguchi
authors.affiliation: Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University School of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, Japan.
authors.forename: Mayu
authors.initials: M
authors.lastname: Ogawa
authors.affiliation: Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University School of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujimoto
authors.affiliation: Yashio Hospital, Yashio-shi, Saitama, Japan.
authors.forename: Aiko
authors.initials: A
authors.lastname: Okamura
authors.affiliation: Kawagoe Hospital, Sakyo-ku, Kyoto, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Shibata
authors.affiliation: Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University School of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, Japan.
authors.forename: Kaeko
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Neuropsychiatry, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan.
authors.forename: Shutaro
authors.initials: S
authors.lastname: Nakaaki
authors.affiliation: Department of Clinical Psychology, Faculty of Social Welfare, Hanazono University, Nishinokyo, Nakagyo-ku, Kyoto, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Koumi
authors.affiliation: Department of Neuropsychiatry, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Mimura
authors.affiliation: Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University School of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Fukui
authors.affiliation: Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University School of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, Japan.
authors.forename: Jin
authors.initials: J
authors.lastname: Narumoto
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology*; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000523:psychology*; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000523:psychology*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D012372:ROC Curve; D014481:United States
keywords: CLOX; EXIT25; Instrumental Activities of Daily Living; dementia; executive function