Get Newsletter
AlzRisk Paper Detail

Reference: Morris, 2001
Cohort: East Boston Established Populations for Epidemiologic Studies of the Elderly
Risk Factor: Blood Pressure

Average Follow-up Time Detail
This study concerned a subset of the East Boston EPESE cohort, comprising participants who were dementia-free at baseline (1982-1983) and who were selected for follow-up to assess AD status in 1985 and 1986. Subset participants were selected using a stratified sampling approach, where strata were based on age, sex, and change in cognitive performance.

The published study by Morris et al, 2001 contributed data to several entries on this page, including two in this table. This entry reflects the 378 participants who had blood pressure measurements taken in both 1972 as part of the Hypertension Detection and Follow-Up Program (HDFP) community screening program (13.6 years prior to AD follow-up) and 1982-1983 as part of the baseline East Boston EPESE assessment (4.5 years prior to AD follow-up).

Exposure Detail
"Of the 378 persons who had their blood pressure measured at both 13 and 4 years before the clinical evaluation for incident AD, 44 had blood pressure levels consistently in the hypertensive range of 160 mm Hg or greater for systolic pressure or 90 mm Hg or higher for diastolic pressure. Of the remainder, 98 subjects had consistently normal blood pressure readings (<140/<85 mm Hg), and 236 persons had mixed (> 160 mm Hg or > 90 mm Hg at 1 time point only) or high-normal (systolic, 140-159 mm Hg; diastolic, 85-89 mm Hg) blood pressure readings at the 2 time points."

"All blood pressure measurements were obtained in participants' homes according to the HDFP protocol. On each occasion, blood pressure was measured 3 consecutive times with 30 seconds between measurements using mercury sphygmomanometers on seated subjects with the arm resting at heart level. For analyses of each time point, the average of the 3 blood pressure measurements was used. A more detailed description of the blood pressure procedures has been published previously.34 All interviewers passed a written test, a videotaped test of blood pressure readings, and live practice tests with a supervisor using a split stethoscope. The overall mean of blood pressure readings by trainees had to be within ±1.96 mm Hg of the standard mean on the videotaped test.35 Data from the HDFP on blinded duplicate blood pressure readings demonstrated good reproducibility of trainee readings."

Ethnicity Detail
No information on the ethnic background of participants has been provided.

Age Detail
The participants were at least 54 years old at the time of the initial blood pressure reading in 1972. Participants were at least 65 years old at the second blood pressure reading in 1982-1983.

Screening and Diagnosis Detail
AD Diagnosis:
Modified NINCDS ADRDA "Modified" National Institute of Neurological and Communicative Diseases and Stroke/Alzheimer's Disease and Related Disorders Association Criteria

"The clinical evaluations included a neurological examination, neuropsychological performance testing, a medical history, and a brief psychiatric evaluation. The definition of probable AD was based on criteria consistent with the National Institute of Neurological and Communicative Disorders and Stroke–Alzheimer's Disease and Related Disorders Association.36 We modified the definition to include persons who met the criteria for probable AD and who had a coexisting dementing condition to prevent the possibility of a protective association due to the classification system (for example, if high blood pressure levels were associated with an increased risk of vascular dementia). A more complete description of sampling for incident AD and of the clinical evaluation was published previously.31,37"

Covariates & Analysis Detail
Analysis Type:
Logistic regression

"All models were adjusted for the stratified random sampling using SUDAAN statistical software (Research Triangle Institute, Research Triangle Park, NC)."

AD Covariates:
IDDinterval to disease diagnosis
SSstratified sampling