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Reference: van Oijen, 2005
Cohort: Rotterdam Study
Risk Factor: Inflammatory Biomarkers


Average Follow-up Time Detail
At the baseline examination between 1990-1993, 7047 people were screened for dementia and had blood samples drawn. 334 prevalent cases of dementia were excluded, leaving a cohort of 6713 at risk for dementia. Follow-up examinations occurred between 1993-1994, and again in 1997-1999. In addition, linkage with records of general practitioners allowed for continuous monitoring of the cohort for morbidity and mortality, resulting in complete follow-up through January 1, 2000.

Exposure Detail
"Fibrinogen levels were derived from the clotting curve of the prothrombin time assay using Thromborel S as a reagent on an automated coagulation laboratory (ACL 300, Instrumentation Laboratory). The coefficient of variation was 5%."

Fibrinogen measurements were done at baseline in a random sample and were available for 2835 of the persons at risk.

Ethnicity Detail
Study participants were residents of Ommoord, a suburb of the city of Rotterdam, the Netherlands

Age Detail
The age presented here is the average age at the start of follow-up, in the random cohort with fibrinogen measurements available.

Screening and Diagnosis Detail
Screening Method:
CAMDEXCambridge Examination for Mental Disorders of the Elderly
GMSGeriatric Mental State Schedule (Copeland 1976)
MMSEMini-Mental State Examination (Folstein 1975)

AD Diagnosis:
NINCDS ADRDA National Institute of Neurological and Communicative Diseases and Stroke/Alzheimer's Disease and Related Disorders Association Criteria (McKhann 1984)

Total dementia definition: DSM-III-revised.

Screening: (Described in van Oijen et al. 2005) "The diagnosis of dementia was made following a 3-step protocol. Two brief tests of cognition (Mini-Mental State Examination [10] and Geriatric Mental State schedule [11] organic level) were used to screen all of the subjects. Screen-positives (Mini-Mental State Examination score 26 or Geriatric Mental State organic level 0) underwent the Cambridge examination for mental disorders of the elderly (Camdex) [12]. Subjects who were suspected of having dementia were, if necessary, examined by a neuropsychologist. In addition, the total
cohort was continuously monitored for incident dementia through computerized linkage between the study database and digitalized medical records from general practitioners and the Regional Institute for Outpatient Mental Health Care."

Covariates & Analysis Detail
Analysis Type:
Cox proportional hazards regression

Fibrinogen was normally distributed. This table displays the results for fibrinogen entered as a linear term in a Cox proportional hazards model. In Table 8, we provide the results for fibrinogen as quintiles.

AD Covariates:
Aage
Ggender
APOE4APOE e4 genotype
ATHatherosclerosis
BMIbody mass index
DMdiabetes mellitus
DBPdiastolic blood pressure
HDLHDL cholesterol
SMsmoking status
SHstroke history
SBPsystolic blood pressure
TCtotal cholesterol

TD Covariates:
Aage
Ggender
APOE4APOE e4 genotype
ATHatherosclerosis
BMIbody mass index
DMdiabetes mellitus
DBPdiastolic blood pressure
HDLHDL cholesterol
SMsmoking status
SHstroke history
SBPsystolic blood pressure
TCtotal cholesterol

In addition to the results we display here, the authors report results for another model that adjusts for age, sex, C-reactive protein, and white blood cell count. Results for both models are similar, so we display the results from the more fully-adjusted model.