title: A cost effective method of identifying and recruiting persons over 80 free of dementia or mild cognitive impairment.
abstract: For observational or prevention studies, accurately identifying by mail and telephone cognitively normal elderly volunteers would be cost effective. We describe how to recruit cognitively normal sib-pairs over age 80 using commercially available lists by age and ZIP code. We mailed an Institutional Review Board-approved letter to 24,366 persons over 85 around Jacksonville, FL, and received approximately 3,000 postcard replies with approximately 500 answering 3 screening statements affirmatively. Of these, we recruited 128 persons who underwent both in-person and telephone evaluations, the latter using the Telephone Interview of Cognitive Status-modified (TICS-m) and Clinical Dementia Rating scale (CDR). Blinded to the TICS-m and CDR data, clinicians made a consensus diagnosis for each participant, 120 were normal and 8 had mild cognitive impairment. With CDR, 119 patients (93%) screened as normal, and of these 115 (97%) were confirmed as normal with the consensus diagnosis. A TICS-m score cut-off of <29 resulted in a similar proportion of normals in the screened sample (97% or 103/106); however, 13 normal volunteers would have been excluded because they scored <29 on the TICS-m. Supplementing the sample, we recruited 12 age-matched cases having consensus diagnosis of dementia (n=2) or mild cognitive impairment (n=10). A CDR>0 correctly identified 12/12, whereas the TICS-m <29 correctly identified 7/12. Hearing loss present in 50% did not influence TICS-m or CDR performance. Using stringent entry criteria and the telephone CDR, this method accurately identified normal elderly persons.
authors.affiliation: Department of Neurology, Biostatistics Unit at Mayo Clinic Jacksonville, Jacksonville, Florida 32224, USA. graffradford.neill@mayo.edu
authors.forename: Neill R
authors.initials: NR
authors.lastname: Graff-Radford
authors.forename: Tanis J
authors.initials: TJ
authors.lastname: Ferman
authors.forename: John A
authors.initials: JA
authors.lastname: Lucas
authors.forename: Heather K
authors.initials: HK
authors.lastname: Johnson
authors.forename: Francine C
authors.initials: FC
authors.lastname: Parfitt
authors.forename: Michael G
authors.initials: MG
authors.lastname: Heckman
authors.forename: Murray
authors.initials: M
authors.lastname: Todd
authors.forename: Carl
authors.initials: C
authors.lastname: Sadowsky
authors.forename: Dawn E
authors.initials: DE
authors.lastname: Epstein
authors.forename: Julia E
authors.initials: JE
authors.lastname: Crook
mesh_terms: D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis*; D003072:Cognition Disorders / Q000175:diagnosis*; D003362:Cost-Benefit Analysis; D005260:Female; D005431:Florida; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008403:Mass Screening / Q000191:economics*; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D018579:Patient Selection; D012016:Reference Values; D015203:Reproducibility of Results