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DLM: Alcohol (2001)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To determine the association between self-reported alcohol intake and coronary disease was studied prospectively among male health professionals.

Inclusion Criteria:
  • 51,529 male health professionals
  • 40 to 75 years of age.

 

Exclusion Criteria:
  • Questionable FFQ data
  • History of cancer, MI, angina, stroke, coronary artery bypass graft (CABG), percutaneous transluminal coronary angioplasty (PTCA)
  • 1,530 men, who did not report an avenge daily food intake of 3.35 to 17.6Mj (800 to 4,200kcal) and who did not eat more than 70 food items on the dietary questionnaire
  • 5,940 men who reported a diagnosis of cancer (except non-melanoma skin cancer), MI, angina, stroke or CABG or PTCA on the 1986 questionnaire.
Description of Study Protocol:
  • The association between self-reported alcohol intake and coronary disease was studied prospectively among 51,529 male health professionals
  • In 1986 the participants completed questionnaires about food and alcohol intake and medical history, heart disease risk factors and dietary changes in the previous 10 years. 
  • Follow-up questionnaires in 1988 sought information about newly diagnosed coronary disease. Three-hundred fifty confirmed cases of coronary disease occurred.
  • The 131-item semi-quantitative FFQ included questions about average consumptions during the past year or beer, white wine, red wine and spirits
  • The nine frequency response categories ranged from never or less than once per month to six times or more per day. Standard specified portion sizes were one glass, bottle or cans of beer, four ounce (118ml) glass for wine and one measure for spirits.
  • Alcohol and nutrient intake were calculated from the frequency of consumption multiplied by the nutrient content of each food or beverage
  • Different statistical analysis were conducted to assess the association of alcohol consumption CHD risk. 

 

Data Collection Summary:
  • Data collected:
    • 1986: Baseline FFQ including alcohol intake, medical history, heart disease risk factors and dietary changes over the past 10 years
    • 1988: Information on newly diagnosed coronary disease or death (from baseline data collected in 1986 and Jan 31, 1988)
    • Medical records, National Death Index and death records to confirm diagnosis
  • Outcome measures:
    • Fatal CHD
    • Non-fatal MI
    • CABG
    • PCTA.
Description of Actual Data Sample:

44,059 men were eligible for the study

  • 350 cases of CHD
  • 50 cases of death from CHD
  • 136 CABG or PTCA procedures
  • 164 nonfatal MI.
Summary of Results:
  • Alcohol intake:
    • Less than one month 23.4% greater than 15g per day 26.4% greater than 50g per day 3.5%
    • After adjustment for coronary risk factors, including dietary intake of cholesterol, fat and dietary fiber, alcohol intake was inversely related to CHD incidence (P for trend <0.001)
    • The adjusted RR of CAD from all causes was lower in those using greater than 30.1g ethanol per day compared to abstainers: RR 0.53 (95% CI, 0.35 to 0.79)
    • Compared with non-drinkers, men drinking more than 30g per day had a RR of CHD of 0.61 (95% CI, .32-1.17)
  • The RR of CAD was 0.55 (0.39 to 0.77) for men who drank 30.2g (two drinks) of spirits compared those not drinking spirits
  • These findings provide additional evidence to support the hypothesis that moderate alcohol consumption decreased the risk of CAD.
Author Conclusion:
  • Included dietary assessment and risk factors for CVD
  • Validated FFQ
  • The prevalence of hypertension was similar among abstainers and light drinkers, but higher in men with intake of greater than 30g ethanol per day
  • Men consuming ­amounts of alcohol also consumed more fat and cholesterol and less dietary fiber than abstainers
  • Diabetes was more common among abstainers.
Funding Source:
Government: National Institute of Health, Environmental Health Sciences
Reviewer Comments:
  • This is a very well-written paper with different statistical analysis to find the association of alcohol and risk of CHD in men
  • This is a prospective study reported in males
  • Further controlled trials are required to study the association of different alcoholic beverages and the risk of CHD (e.g., beer may enhance triglycerides)
  • Similar studies are required in female population and in different ethnic, economic and population groups.
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? N/A
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? Yes
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) Yes
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? N/A
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) ???
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? N/A
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  6.6. Were extra or unplanned treatments described? Yes
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? Yes
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? Yes
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes