Study participants were enrolled at the University of Pittsburgh Alzheimer’s Disease Research Center (ADRC), all of whom met the National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer’s Disease and Related Disorders Association clinical criteria for probable AD. Each participant had undergone an extensive neuropsychiatric evaluation, which has been described in detail previously. Briefly, this involved a physical examination, neurological examination, semistructured psychiatric interview, and neuropsychological assessment. All patient records were reviewed at a multidisciplinary clinical consensus conference for assignment of a diagnosis. The inclusion/exclusion criteria have been published previously, but it is important to note that one of the criteria was that all the patients had to have a reliable caregiver that could provide detailed information about the patients’ clinical symptoms and their activities of daily living (ADLs). The caregiver was interviewed in person once a year and by phone every 6 months. In case of loss of a caregiver, the data were censored as the last date that reliable information was received from the caregiver.

Lopez OL, Becker JT, Saxton J, Sweet RA, Klunk W, DeKosky ST. Alteration of a clinically meaningful outcome in the natural history of Alzheimer’s disease by cholinesterase inhibition. J Am Geriatr Soc. 2005 Jan;53(1):83-7. doi: 10.1111/j.1532-5415.2005.53015.x. PMID: 15667381.