Get Newsletter
AlzRisk Paper Detail

Reference: Luchsinger, 2004
Cohort: Washington Heights-Inwood Columbia Aging Project
Risk Factor: Alcohol

Average Follow-up Time Detail
Average follow-up time and person-years both reported.

Exposure Detail
Investigators collected data on participants’ consumption of many types of alcoholic beverages. This entry pertains to liquor consumption.

Nondrinkers (0 servings reported)
Light-moderate drinkers (light: 1 serving a month to 6 servings a week, moderate: 1 to 3 servings a day)
Heavy drinkers (>3 servings a day)

"Dietary data were obtained using a 61-item version of Willett’s semiquantitative food frequency questionnaire (SFFQ) (Channing Laboratory, Cambridge, MA).13 Trained interviewers administered in English or Spanish the SFFQ by telephone between the baseline and first follow-up examinations. The questionnaire inquired about servings of beer, liquor, and wine by serving frequency; possible answers were one to three servings/month, one serving a week, two to four servings a week, five to six servings a week, one serving a day, two to three servings a day, four to five servings a day, and more than six servings a day. One serving of beer was equivalent to 12 oz (12.8 g of alcohol), one serving of liquor was equivalent to 1.5 oz (14 g of alcohol), and one wine serving was equivalent to 4 oz (11 g of alcohol). In light of the possibility of nonspecific alcohol effects and specific nonalcoholic effects of the different beverages, alcohol intake was examined in two ways: by examining the association between beer, liquor, and wine servings separately with incident dementia and by examining the association between total alcohol servings and dementia. Individuals were classified as nondrinkers (0 servings reported), light drinkers (1 serving a month to 6 servings a week), moderate drinkers (1 to 3 servings a day), and heavy drinkers (>3 servings a day); this classification was made trying to resemble previous publications in this field2 for the sake of comparability and following the format of the questionnaire. Because of a low number of moderate drinkers, the light and moderate drinkers were aggregated in one category (1 serving a month to 3 servings a day). Heavy alcohol intake was included despite the low number of individuals in this category because heavy alcohol intake may increase the risk of dementia.14 SFFQs have been used and validated for the determination of nutrient intake in the elderly.15–19 The validity of the food frequency questionnaire used in the Washington Heights–Inwood Columbia Aging Project cohort was assessed in a subsample of 78 individuals using two 7-day food records as the criterion. The correlation for energy adjusted alcohol intake was 0.44 (P<.01) (M. Siddiqui, personal communication, December 7, 2000). The reliability of the alcohol intake measure was compared between two SFFQs administered 2 months apart, and the measurements were not significantly different."

Ethnicity Detail
"Ethnic group was based on self-report using the format of
the 1990 census.20 Individuals were also asked whether they were of Hispanic origin. Participants were then assigned to one of three groups: black (non-Hispanic),
Hispanic, or white (non-Hispanic). Ethnic group was not
found to significantly alter the models and was not included in the analyses."

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

"A group of neurologists, psychiatrists, and neuropsychologists made a diagnosis of dementia and assignment of specific cause by consensus based on the information gathered at the initial and yearly follow-up visits. The diagnosis of dementia was based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria8 and required evidence of cognitive deficit on the neuropsychological test battery and evidence of impairment in social or occupational function; persons with a global summary score on the Clinical Dementia Rating (CDR) of 0.5 or more were considered to have dementia.9 Diagnosis of Alzheimer’s disease (AD) was based on the National Institute of Neurological and Cognitive Disorders and Stroke-Alzheimer’s Disease and Related Disorders Association criteria.10 Diagnosis of dementia associated with stroke (DAS) was made in all subjects with a history of stroke. Because moderate alcohol intake is related to a lower risk of stroke,11 a less conservative definition of DAS was used to avoid finding an association between alcohol and AD because of misclassification of DAS as AD. Brain imaging was available in 85% of cases of stroke; in the remainder, World Health Organization criteria were used to define stroke.12 Subjects without dementia but with a history of stroke at the baseline examination were included in the analyses. These criteria and diagnostic methods have been used extensively in analysis of data in this cohort."

Covariates & Analysis Detail
Analysis Type:
Cox proportional hazards regression

"Cox proportional hazards regression was used for multivariate analyses, with the time-to-event variable in the models specified as time from baseline examination to onset of dementia. Individuals with dementia not caused by the subtype of interest were censored at the time of onset of dementia."

AD Covariates:
APOE4APOE e4 genotype