Heart Failure

HF: Alcohol Intake (2007)

Citation:

Salisbury AC, House JA, Conard MW, Krumholz HM, Spertus JA. Low-to-Moderate Alcohol Intake and Health Status in Heart Failure Patients, J Cardiac Failure. 11 (5): 323-328, 2005.

 
Study Design:
Longitudinal
Class:
C - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To understand the health status of low to moderate drinkers with non-drinkers and to explore whether alcohol consumption is associated with a different trajectory of health status over time in heart failure patients. 

Inclusion Criteria:
  • 30 years or older
  • Documentation of heart failure (HF) in their medical records
  • Prior hospitalizaiton for decompensated HF in the past three years or an ejection fraction of under 40%.
Exclusion Criteria:

None.

Description of Study Protocol:
  • Recruitment: Outpatients from 13 North American centers through the Cardiovascular Outcomes Research Consortium 
  • Design: Longitudinal.

Statistical Analysis

  • Univariate analysis of baseline characteristics of patients consuming low to moderate amounts of alcohol (one to 60 drinks per month) were compared with those who abstained from alcohol using Students' T-test for continuous variables and chi-square tests for categorical variables
  • To define the independent cross-sectional association between drinking status and health status, scores of all baseline variables that differed significantly between low-to-moderate drinkers and abstainers were eligible for entry into multivariable models
  • Models having variables with a P-value under 0.10 were potentially entered. Multivariable linear regression was then used to adjust for the demographic, cardiac, comorbid and HF treatment variables.
  • Both logistic regression and Cox proportional hazards models were used to determine the difference in risk between the two groups for mortality and hospitalization, while controlling for baseline differences between the groups
  • The study had a 90% power to detect a seven-point difference in one-year KCCQ change scores, the primary health status measure, with type I error at 0.05
  • Statistical analyses were performed using SAS version 8.2. For all analyses, a P-value equal to or less than 0.05 was considered statistically significant.
Data Collection Summary:

Timing of measurements: Baseline and one-year follow-up.

Dependent Variables

  • Variable One: Disease-specific KCCQ and generic Short Form-12 (SF-12) health status questionnaires
    • The KCCQ is a 23-item, self-administered questionnaire with scales measuring multiple health status domains, including symptoms, physical function, social function, self-efficacy and quality of life. These are summarized by a single score that reflects patients' overall health status, where higher scores represent better physical and social function, higher quality of life and fewer symptoms. Score changes of five points or greater are considered clinically significant.
    • The SF-12 is a measure of overall physical and mental health. It generates a summary score with higher scores, representing better health status. A score of 50 is normalized to the mean health status of the US population and each 10 points represents one standard deviation from that mean.
    • Both questionnaires are validated, reliable measurement tools. 
  • Variable Two: HF hospitalization and mortality within one year of baseline assessment.

Independent Variables

  • Alcohol drinking patterns were obtained by self-report, using elements of the World Health Organization's Alcohol Use Disorders Identification Test (AUDIT)
  • Patients consuming between one and 60 drinks per month (two or fewer drinks per day) were classified as low to moderate drinkers.
Description of Actual Data Sample:
  • Initial N: 547.

Attrition (Final N)

  • 420 (82.9% male among abstainers and 71.8% among low to moderate drinkers; P=0.009) with complete baseline data
  • 45 deaths over the year follow-up
  • 291 surviving patients with complete follow-up interviews.  

Age

  • Abstainers: 62.7±12.8
  • Low to moderate drinkers: 59.7±13.6
  • P=0.02.

Ethnicity

62.9% of the abstainers and 73.6% of the low to moderate drinkers were Caucasian (P=0.02). No further description provided.

Anthropometrics

  • The low to moderate drinkers had a slightly lower NYHA class (2.3±0.8 vs. 2.5±0.7; P<0.001) and were more likely to smoke (67.7% vs. 54.3%; P=0.02), but less likely to have diabetes (19.4% vs. 44.5%, P<0.001) or hypertension (51.4% vs. 62.0%; P=0.03)
  • There was no significant difference in HF etiology and both groups received similar HF medications. 

Location

13 North American centers.

Summary of Results:

Other Findings

  • Both groups had similar baseline KCCQ overall summary (60.5±24.0 vs. 61.9±23.5; P=0.55), SF-12 physcial component (33.6±11.2 vs. 35.3±10.2; P=0.14) and SF-12 mental component (49.1±11.1 vs. 49.4±11.4; P=0.78) scores
  • After one year of follow-up, there were no further significant health status differences between the remaining 174 abstainers and 117 low to moderate drinkers, as measured by the KCCQ overall summary (65.8±24.5 vs. 69.3±24.2; P=0.23). Abstainers had a one-year KCCQ change score of 3.5±22.3 vs. 5.3±21.5 in the low to moderate drinkers (P=0.49). SF-12 summary scores were not obtained at the one-year follow-up.
  • There were no significant differences in HF hospitalization rates between the two groups (18% vs. 15.4%; P=0.51). The survival rates did not differ between the two groups either (10.5% in abstainers vs. 11.6%; P=0.72). Time to event analyses confirmed no difference between the groups in their rates of death (P=0.75) or hospitalization (P=0.49). 
  • Adjustment for baseline age, gender and race and clinical factors also did not find any differences between the groups either at baseline or at one-year follow-up. Logistic regression analyses controlling for baseline demographic and clinical characteristics found no differences between the two groups for one-year hospitalization or death.
Author Conclusion:

Low to moderate levels of alcohol consumption do not worsen patients' symptoms, function and quality of life, nor does it effect one-year mortality or hospitalization rates. 

Funding Source:
University/Hospital: University of Missouri KC, Saint Luke's Hospital, Yale Univesity
Reviewer Comments:
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
  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
  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
  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
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
Validity Questions
  1. Was the research question clearly stated? Yes
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.1. 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
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
  1.3. Were the target population and setting specified? Yes
  2. Was the selection of study subjects/patients free from bias? 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
  2.1. 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
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? 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? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
  3. Were study groups comparable? 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
  3.1. 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
  3.2. 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
  3.3. 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? 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? N/A
  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.) N/A
  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.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
  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. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? 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
  4.2. 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
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
  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? No
5. Was blinding used to prevent introduction of bias? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? 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.) No
  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.) No
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  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
  5.4. 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
  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? Yes
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? 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
  6.2. 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
  6.3. 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
  6.4. 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? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? 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
  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. 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
  7.1. 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
  7.2. 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
  7.3. 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
  7.4. 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
  7.5. 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
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? 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. 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
  8.1. 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
  8.2. 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
  8.3. 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)? N/A
  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)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? 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
  8.6. 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? N/A
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
  9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? 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. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes
  10.2. Was the study free from apparent conflict of interest? Yes