Transcript Related Journal Club Presentation

Journal Club
Alcohol, Other Drugs, and Health: Current Evidence
July–August 2008
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Featured Article
A Prospective Study of Risk
Drinking: At Risk for What?
Dawson DA, et al. Drug Alcohol Depend.
2008;95(1–2):62–72.
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Study Objective
To determine…
• The association between risky drinking
and various adverse outcomes.
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Study Design
• Observational cohort
• Researchers analyzed data from a subgroup
(n=22,122) of the National Epidemiologic Survey
on Alcohol and Related Conditions (NESARC), a
longitudinal sample of US adults.
• Criteria for inclusion in the subgroup were…
– consumption of at least 1 drink in the year
immediately preceding the baseline interview.
– participation in the 3-year follow-up interview.
– nonmissing frequencies of risky drinking at baseline.
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Frequency of Risky Drinking
• In men, frequency was defined as the larger of…
– drinking 5 or more alcoholic drinks in a single day, or
– drinking ≥2.7 ounces (≥4.5 standard drinks) of
ethanol in a single day of coolers, beer, wine, or
spirits, where beverage-specific ounces of ethanol
intake per day were calculated based on number of
drinks, size of drink, and ethanol content of main
brand consumed.
• In women, frequency was defined as the larger of…
– drinking 4 or more alcoholic drinks in a single day, or
– drinking ≥2.1 ounces (≥3.5 standard drinks) of
ethanol in a single day of coolers, beer, wine or
spirits.
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Assessing Validity of an
Article About Harm
• Are the results valid?
• What are the results?
• How can I apply the results to
patient care?
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Are the Results Valid?
• Did the investigators demonstrate similarity in
all known determinants of outcomes? Did they
adjust for differences in the analysis?
• Were exposed patients equally likely to be
identified in the two groups?
• Were the outcomes measured in the same way
in the groups being compared?
• Was follow-up sufficiently complete?
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Did the investigators demonstrate similarity
in all known determinants of outcomes? Did
they adjust for differences in the analysis?
• Baseline characteristics differed by drinking group.
• Analyses were adjusted for the following factors
(which include the differing baseline characteristics):
•
•
•
•
•
•
•
•
•
age
sex
race/ethnicity
marital status
employment
attended/completed college
health status
body mass index
tobacco use
•
•
•
•
•
drug use
any mood or anxiety disorder
any personality disorder
family history of alcoholism
volume of ethanol consumed on days
with no risky drinking
• mean quantity of drinks consumed on
risky drinking days
• years since first drink
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Were exposed patients equally likely
to be identified in the various groups?
• The cohort consisted of 22,122 who participated in the 3year follow-up interview and provided information about
their level of drinking at baseline.
• The cohort was derived from the 43,093 US adults that
participated in the 2001–2002 NESARC survey.
• The NESARC survey consists of individuals 18 years of age
and older, sampled to be representative of the population
residing in households and noninstitutional group settings
in all 50 states and the District of Columbia.
• No information is provided regarding the drinking
(exposure) categories of those who did not complete the
3-year follow-up interview.
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Were the outcomes measured in the
same way in the groups being compared?
 Interviewers were trained by the US Bureau of the
Census.
 Standardized instruments were used to measure
outcomes.
 Limitations:
– Alcohol or drug dependence may have been misclassified.
Investigators considered individuals as meeting criteria for alcohol
or drug dependence if they report only 1 or more of 7 DSM-IV
dependence criteria. Standard criteria requires individuals to meet
at least 3 of 7 DSM-IV dependence criteria.
– Blinding of interviewers to baseline data was not specifically stated.
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Was follow-up sufficiently complete?
• Follow-up surveys were completed approximately
3 years after the baseline survey. This is a brief
period of time for the development of most of the
outcomes.
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What Are the Results?
• How strong is the association between
exposure and outcomes?
• How precise is the estimate of the risk?
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What Are the Results?
Frequency of risky drinking* at baseline
(n=22,122)
Amount
% of
Subjects
no risky drinking
60
<1 time per month
17
1 to 3 times per month
9
1 to 2 times per week
8
3 to 4 times per week
3
daily or near-daily
3
*In this study, defined as 5+ standard drinks in a day for men and 4+ standard
drinks in a day for women.
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What Are the Results? (cont’d)
• At 3-year follow-up, subjects who reported risky
drinking 1 to 2 times per week were more likely
than subjects who reported no risky drinking to
have…
–
–
–
–
–
alcohol abuse
alcohol dependence
drug use
drug dependence
tobacco use
–
–
–
–
nicotine dependence
liver disease
divorced or separated
lost their driver’s licenses
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What Are the Results? (cont’d)
• Subjects who reported daily or near-daily risky
drinking were more likely than subjects who
reported no risky drinking to have…
–
–
–
–
alcohol abuse
alcohol dependence
tobacco use
nicotine dependence
–
–
–
–
liver disease
divorced or separated
exhibited violent behavior
lost their driver’s licenses
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How strong is the association
between exposure and outcomes?
How precise is the estimate of risk?
Odds Ratios (95% CI)
Occurrence of
Adverse Outcomes
Frequency of risky drinking:
1–2 times per week
daily or near-daily
alcohol abuse (n=13,894)
3.29 (2.47–4.38)
3.93 (2.40–6.44)
alcohol dependence (n=18,114)
2.69 (2.00–3.62)
7.23 (4.75–11.00)
drug use (n=15,018)
1.63 (1.19–2.24)
1.87 (1.21–2.88)
drug dependence (n=20,669)
2.32 (1.30–4.14)
2.13 (0.99–4.59)
tobacco use (n=10,418)
2.71 (1.75–4.18)
4.67 (2.16–10.10)
nicotine dependence (n=17,061)
1.77 (1.26–2.48)
3.03 (1.92–4.79)
any liver disease (n=21,200)
2.78 (1.32–5.85)
4.76 (2.29–9.88)
divorce/separation (n=11,665)
1.34 (0.88–2.02)
2.54 (1.50–4.28)
violent behavior (n=21,313)
1.09 (0.78–1.54)
1.61 (1.05–2.47)
driver’s license revoked (n=21,313)
1.81 (1.30–2.54)
2.11 (1.38–3.22)
abuse of spouse (n=11,665)
1.27 (0.87–1.85)
2.06 (1.22–3.46)
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How strong is the association between
exposure and outcomes? How precise is
the estimate of risk? (cont’d)
• The large sample size allowed adjustment for a
wide array of potential confounders.
• Analyses were adjusted for the aforementioned
factors.
• The large sample size also led to relatively
narrow CIs and precise estimates of risk,
although the intervals were wide and less precise
for some rarer outcomes (see table).
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How Can I Apply the Results to
Patient Care?
• Were the study patients similar to the patients
in my practice?
• Was the duration of follow-up adequate?
• What was the magnitude of the risk?
• Should I attempt to stop the exposure?
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Were the study patients similar to the
patients in my practice?
• The sample (n=22,122) was drawn from a
random, representative survey of adults age 18
years and older residing in households and
noninstitutional group quarters in all 50 states.
• As such, they are intended to represent housed
individuals in the US but may differ from
medical treatment seeking individuals.
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Was the duration of follow-up adequate?
• Follow-up surveys were completed approximately
3 years after the baseline survey.
• This may be a short period of time for the
development of:
– chronic and rarer health conditions such as specific
cancers.
– divorce or separation (although an effect was found).
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What was the magnitude of the risk?
• The odds of developing each consequence associated with risky drinking
were 2–3 times greater than in those
who drank less than risky amounts.
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Should I attempt to stop the exposure?
• Yes.
• In addition to other risks, there is good evidence,
in this paper as well as in other studies, that risky
drinking is associated with adverse outcomes such
as…
–
–
–
–
alcohol abuse
alcohol dependence
tobacco use
nicotine dependence
–
–
–
–
liver disease
being divorced or separated
exhibiting violent behavior
losing a driver’s license
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