Advanced Search

Study Preview



Study Title and Description

Long-term alcohol and caffeine intake and risk of sudden cardiac death in women.



Key Questions Addressed
1 For [population], is caffeine intake above [exposure dose], compared to intakes [exposure dose] or less, associated with adverse effects on cardiovascular outcomes?
  • Comments Comments (
    0
    ) |

Primary Publication Information
  • Comments Comments (
    0
    ) |
TitleData
Title Long-term alcohol and caffeine intake and risk of sudden cardiac death in women.
Author ML Bertoia,EW Triche,DS Michaud,A Baylin,JW Hogan,ML Neuhouser,MS Freiberg,MA Allison,MM Safford,W Li,Y Mossavar-Rahmani,MC Rosal,CB Eaton,
Country
Year 2013
Numbers

Secondary Publication Information
There are currently no secondary publications defined for this study.


Extraction Form: Cardiovascular Design
Design Details
Question... Follow Up Answer Follow-up Answer
What outcome is being evaluated in this paper? Cardiovascular
  • Comments Comments (
    0
    ) |
What is the objective of the study (as reported by the authors)? Our objective was to examine the association between long-term alcohol and caffeine intakes and risk of sudden cardiac death (SCD) in women.
  • Comments Comments (
    0
    ) |
Provide a general description of the methods as reported by the authors. Information should be extracted based on relevance to the SR (i.e., caffeine related methods) Subjects: The Women’s Health Initiative (WHI) Observational Study included 93,676 study participants at 40 study sites across the United States (21). All participants were female, postmenopausal, and aged 50–79 y at baseline (1993–1998). Exposure measurement: Dietary intake (total alcohol, wine, beer, liquor, and total caffeine) was measured in the WHI by using a validated (23) semiquantitative food-frequency questionnaire (FFQ) designed specifically for this postmenopausal population. Women completed the FFQ at baseline and year 3. The WHI FFQ asked participants to recall diet over the past 3 mo and included 122 items. Total caffeine intake (in g/d) was calculated from the FFQ based on intake of the following beverages: soda (all types), coffee, and tea. Intake of these beverages was reported according to the same frequency categories as alcohol, and medium servings were defined as 12 oz (355 mL) or 1 can of soda and an 8-oz (237- mL) cup of coffee or tea. The FFQ did not differentiate between caffeinated and decaffeinated soda, coffee, or tea. The FFQ also did not ask about chocolate intake, so we could not consider this source of caffeine in the diet. The caffeine content of medications was not available in this data set; therefore, we were unable to consider this source of caffeine intake. The WHI FFQ nutrient database was derived from the Nutrition Data Systems for Research food and nutrient database (Nutrition Coordinating Center, University of Minnesota) (23). Although the FFQ did not distinguish between caffeinated and decaffeinated coffee and tea, a separate questionnaire administered at baseline asked women about their usual consumption of regular (caffeinated) coffee, decaffeinated coffee, and regular tea. The exact questions were as follows: "How many cups of regular coffee (not decaf) do you usually drink each day? [count tall (12 oz. or more) cups and espresso drinks made with double shots as 2 cups]," "How many cups of decaf coffee do you usually drink each day? [count tall (12 oz. or more) cups and espresso drinks made with double shots of espresso as 2 cups]," and "How many cups of tea do you usually drink each day? (do not include decaf or herbal tea)." Outcome measurement: Our primary endpoint, incident SCD, was defined as death from fatal MI, fatal definite CAD, or fatal possible CAD, and this cardiac death must have occurred within 1 h of symptom onset. Trained physician adjudicators reviewed medical records of potential CAD death cases, including death certificates, autopsy reports, circumstances of death recorded by next of kin, and all hospital records, including electrocardiograms, laboratory test results, and reports from all relevant cardiac procedures (hospitalized and non-hospitalized). The medical record or interview of witnesses had to document that patient collapse was directly observed, as by hospital notes and cardiopulmonary resuscitation records or by a relative or observer clearly reporting that the patient was found unresponsive within ,60 min from previous direct observation of stable clinical status. As a secondary analysis, we also examined non-SCD, defined as death >24 h after symptom onset. We excluded rapid deaths (1–24 h; n = 157) from all analyses (SCD and non-SCD) because of potential misclassification bias. Trained certified staff also measured pulse, and participants additionally reported their diet (with a validated FFQ) and comorbidities/disease history at baseline.
  • Comments Comments (
    0
    ) |
How many outcome-specific endpoints are evaluated? 1
  • Comments Comments (
    0
    ) |
What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately) Sudden cardiac death (SCD)
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately). 2
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately).3
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately).4
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately).5
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately).6
  • Comments Comments (
    0
    ) |
Clinical, physiological, other Clinical
  • Comments Comments (
    0
    ) |
What is the study design? Cohort
  • Comments Comments (
    0
    ) |
Randomized or Non-Randomized?
  • Comments Comments (
    0
    ) |
What were the diagnostics or methods used to measure the outcome? Objective
  • Comments Comments (
    0
    ) |
Optional: Name of Method or short description Our primary endpoint, incident SCD, was defined as death from fatal MI, fatal definite CAD, or fatal possible CAD, and this cardiac death must have occurred within 1 h of symptom onset. Trained physician adjudicators reviewed medical records of potential CAD death cases, including death certificates, autopsy reports, circumstances of death recorded by next of kin, and all hospital records, including electrocardiograms, laboratory test results, and reports from all relevant cardiac procedures (hospitalized and non-hospitalized). The medical record or interview of witnesses had to document that patient collapse was directly observed, as by hospital notes and cardiopulmonary resuscitation records or by a relative or observer clearly reporting that the patient was found unresponsive within <60 min from previous direct observation of stable clinical status. As a secondary analysis, we also examined non-SCD, defined as death >24 h after symptom onset. We excluded rapid deaths (1–24 h; n = 157) from all analyses (SCD and non-SCD) because of potential misclassification bias.
  • Comments Comments (
    0
    ) |
Caffeine (general)
  • Comments Comments (
    0
    ) |
Coffee, Chocolate, energy drink, gum, medicine/supplement, soda, tea, other? Coffee, tea
  • Comments Comments (
    0
    ) |
Measured or self reported? Self-report
  • Comments Comments (
    0
    ) |
Children, adolescents, adults, or pregnant included? Adults
  • Comments Comments (
    0
    ) |
What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.) Caffeine exposure: 1st quintile (0-58 mg caffeine/day) Regular coffee: No cups/day Decaffeinated coffee: No cups/day Regular tea: No cups/day
  • Comments Comments (
    0
    ) |
What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models.  Copy from methods) Women were excluded if they did not provide written informed consent, did not plan to reside in the study recruitment area for >-/ 3 y, had medical conditions predictive of a survival time of <3 y, had characteristics inconsistent with study compliance (alcoholism, drug dependency, mental illness, dementia), or were actively participating in another controlled trial. Other exclusion criteria were used for each of the trials, as described previously (22). HRs for SCD according to quintile or category of nutrient intake were computed with the use of Cox proportional hazards models, with control for confounders. Because alcohol and caffeine intakes did not remain constant between baseline and year 3, we used Cox proportional hazards regression with time-dependent exposure and covariates (diseases) using previously described methods (25). This approach uses information from both the FFQ completed at baseline and the FFQ completed at year 3. Potential confounders were identified based on previous knowledge and existing literature. Potential confounders were included as covariates in multivariable models if the variable was 1) associated with both SCD and the exposure of interest using a P value </=0.20 and 2) not on the causal pathway. Diseases such as diabetes and hypertension may be on the causal pathway because they can be caused in part by poor diet, and they are risk factors for SCD. To control for this, and to explore effect modification, we additionally ran our analysis stratified by CAD status at baseline. Furthermore, we present a fully adjusted model (model 2) and a model that includes the following potential mediators: atrial fibrillation, CAD, heart failure, diabetes, high cholesterol, and hypertension (model 3). We adjusted for energy intake by including total energy (kcal/d) in our multivariable models. We checked for multicollinearity among covariates, and none had a variance inflation factor >2.0.
  • Comments Comments (
    0
    ) |
What conflicts of interest were reported? "No conflicts of interest were declared."
  • Comments Comments (
    0
    ) |
Refid 23615825
  • Comments Comments (
    0
    ) |
What were the sources of funding? "The Women’s Health Initiative program is funded by the National Heart, Lung, and Blood Institute, NIH, US Department of Health and Human Services (contracts N01WH22110, 24152, 32100-2, 32105-6, 32108-9, 32111-13, 32115, 32118-32119, 32122, 42107-26, 42129-32, and 44221)."
  • Comments Comments (
    0
    ) |




Results & Comparisons

No Results found.