Visit, Home

The Memory and Aging Project is funded by the National Institute on Aging and was approved by the Institutional Review Board of Rush University Medical Center. Older persons without known dementia must agree to an assessment of risk factors, blood donation, and a detailed clinical evaluation each year. Further, all participants also agree to donation of brain, the entire spinal cord, and selected nerve and muscles at the time of death.
Study participants are primarily recruited from retirement communities throughout northeastern Illinois Fig. (1). The study primarily enrolls residents of continuous care retirement communities. Several features of these facilities and the study design enhance the validity and generalizability of the study. Because the only exclusion is the inability to sign the Anatomical Gift Act, and because all clinical evaluations are performed as home visits, co-morbidities common in population-based epidemiologic studies are well represented; this reduces the “healthy volunteer effect” seen in many cohort studies [30 (link)]. The home visits reduce participant burden facilitating high rates of follow-up. Follow-up rates are further enhanced because these facilities provide all levels of care from independent living to unskilled and skilled nursing on campus. This also enhances autopsy rates as many participants die on campus and the Anatomical Gift Act allows us to work directly with facility staff and the funeral home to arrange the autopsy. Residents of continuous care retirement communities are predominantly white and tend to be more affluent. Therefore, the study also recruits from Section 8 and Section 202 housing subsidized by the Department of Housing and Urban Development, retirement homes, and through local churches and other social service agencies serving minorities and low-income elderly.
The study design allows the following types of analyses to be conducted within a single dataset Fig. (2): 1) the relation of risk factors with incident AD, incident MCI, and decline in cognitive and motor function; 2) the relation of neurobiologic indices with AD, MCI, and cognitive and motor function; and 3) modeling neurobiologic pathways linking risk factors to clinical phenotypes.

The study population included all Medicare beneficiaries, 18 years and older, who received home health care in 2015 (4,243,090 people). Two data sources containing three race/ethnicity variables for our sample of Medicare beneficiaries were linked using the unique Chronic Conditions Warehouse (CCW) beneficiary identification number for the entire study population: The 2015 Medicare Beneficiary Summary File (MBSF) containing the Enrollment Database (EDB) race variable and Research Triangle Institute (RTI) race variable; and the 2015 Outcome and Assessment Information Set (OASIS) containing the ‘gold-standard’ self-reported race/ethnicity for all home health care patients. All three race variables (EDB, RTI, OASIS) were available for the entire study population.
During the initial home health care visit by a registered nurse or licensed physical therapist, as part of the standardized OASIS assessment, race/ethnicity data are obtained by self-report (a caregiver may answer if the patient is unable) and allows for multiple answers to be recorded. The directions for this question include the words “Mark all that apply” and the response choices are: 1) American Indian or Alaska Native, 2) Asian, 3) Black or African-American, 4) Hispanic or Laino, 5) Native Hawaiian or Pacific Islander, and 6) White.
For the purposes of this paper, and for consistency with the EDB and RTI race variable categories, beneficiaries who self-identified as either or both 1) Asian and 2) Native Hawaiian or Pacific Islander were classified as Asian American/Pacific Islander (AAPI). The vast majority (99.73%) of home health beneficiaries had only a single race/ethnicity recorded, and we restricted our study to this population. Details of the remaining 11,720 people (0.27% of study population) who identified with two or more racial/ethnic groups are included for the interested reader as a brief Appendix. Our final study sample consisted of 4,231,370 adult Medicare beneficiaries who received home health care in 2015. The study was approved by the Institutional Review Board of [replace with the authors’ academic institution].