DLM: Alcohol and Coronary Heart Disease (2007-2010)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
to analyze the relationship between an aspect of drinking pattern (i.e. drinking with or without meals) and risk of all cause and specific-cause mortality.
Inclusion Criteria:
  • enrolled in the Italian Risk Factor and Life Expectancy Pooling Project
  • Italian
  • enrolled in a study that included alcohol consumption assessment
  • aged 30-59 years at baseline
  • male and female
Exclusion Criteria:
  • missing information re cigarette smoking
  • positive self-report of CVD at baseline
  • out of selected age range
Description of Study Protocol:

Recruitment

  • participants in 4 of 9 different large-scale epidemiological studies involving 47 population samples were recruited from electoral rolls (45 studies) or from occupation settings (2 samples). 
  • 4 studies had queried alcohol consumption; these were used
  • presumably participants were volunteers  

Design

prospective cohort study:

  • Independent variable (pattern of alcohol use) and risk factor variables (age, TC, TG, blood pressure, cigarette smoking, weight for height, and CVD history) assessed in baseline year.
  • Dependent variable (mortality) assessed 10 years later.
  • Hazard ratios determined.

Blinding used (if applicable)

No blinding reported.

Standardized analytical procedures used.

Intervention (if applicable)

No intervention.

Statistical Analysis

Cox's Proportional Hazard Model was primary mode of multivariate analysis, comparing mortality from various causes among different patterns of alcohol use, adjusting for age, smoking, TC, TG, and blood pressure

Data Collection Summary:

Timing of Measurements

Independent variable measured at baseline; mortality assessed ten years later.

Dependent Variables

  • Variable 1: Mortality; date and cause of death collected by the responsible investigators of the individual cohorts.  Classified as cardiovascular disease (CVD), coronary heart disease (CHD), cerebrovascular disease, cancer, and noncardiovascular disease.

Independent Variables

  • Alcohol consumption; participants queried at baseline about amount and pattern of alcohol consumption.  Only pattern reported.
    • predominately drinkers of wine only at meals
    • predominately drinkers of wine both at meals and outside meals
    • wine at meals as well as other liquors
    • no alcohol use

Control Variables

  • age in years
  • TC and TG assessed after 12 hr fast, quality control from WHO Lipid Reference Center
  • blood pressure in right arm, seated, after 4 min rest, trained by WHO Cardiovascular Survey Methods Manual.
  • Cigarette smoking, self report classified as current, ex-, or never smoker.
  • Weight and height as per WHO Manual
Description of Actual Data Sample:

Initial N: (e.g., 731 (298 males, 433 females))  8980  males, 6669 females

Attrition (final N): 8647 males, 6521 females

Age: 40-69 at end of study

Ethnicity: Italian

Other relevant demographics:

Anthropometrics (e.g., were groups same or different on important measures)  alcohol use groups differed in age, serum lipids, and blood pressure; these were controlled for statistically.

Location: Italy

 

Summary of Results:

Among both males and females highest all cause mortality was seen among those drinking wine outside of meals.  This association was seen with CHD and CVD, among males but the numbers were too low among the females to make the parallel comparisons. No  reports or comparisons were made re amounts of alcohol consumed.

Findings on Males

no alcohol

RR/95% CI

N=74

wine at meals

RR/95% CI

N=310

wine outside meals

RR/95% CI

N=600

wine & liquor

RR/95% CI

N=1438

all causes 1 0.64/0.49-0.82 1.13/0.82-1.61 0.73/0.53-1.00
death from CHD 1 0.50/0.33-0.74 0.81/0.45-1.41 0.62/0.38-1.03
death from CVD 1 0.48/ 0.30-0.76 0.79/0.40-1.33 0.74/0.41-1.25

Findings with females

Findings

 with females

no alcohol

RR/95% CI

N=2195

wine at meals

RR/95% CI

N=4090

wine outside meals

RR/95% CI

N=38

wine & liquor

RR/95% CI

N=198

all causes 1 0.87/0.63-1.21 3.48/1.25-9.66 0.71/0.26-1.97
death from non-CVD 1 0.96/0.66-1.40 4.82/1.72-13.52 0.94/0.33-2.63

all other causes too few

to analyze

Author Conclusion:

Mortality was usually lower among groups drinking some alcohol. Drinking patterns may have important health implications. This study showed a positive association of drinking wine outside of meals and mortality among both males and females.

Funding Source:
University/Hospital: State University of New York at Buffalo, Associazione per la Ricerca Cardiologica (Italy), Istituto Superiore di Sanitá (Italy)
Reviewer Comments:
This study seems uneven in its care in determining mortality; no details are given as to efforts to verify deaths and their cause. The number of females consumming alcohol predominantly outside of meals is only 38 (2.6% of sample), seemingly too few upon which to base conclusions.   The lack of attention to amounts consummed is troublesome.
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? Yes
  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? ???
3. Were study groups comparable? ???
  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? No
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  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.) ???
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? ???
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? ???
5. Was blinding used to prevent introduction of bias? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? ???
  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.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? ???
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? ???
  5.5. In diagnostic study, were test results blinded to patient history and other test results? ???
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? ???
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? No
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? ???
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? No
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? ???
  6.6. Were extra or unplanned treatments described? ???
  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? ???
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? ???
  7.5. Was the measurement of effect at an appropriate level of precision? ???
  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)? ???
  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? No
  8.7. If negative findings, was a power calculation reported to address type 2 error? ???
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? No
  10.1. Were sources of funding and investigators' affiliations described? No
  10.2. Was the study free from apparent conflict of interest? No