Journal Club

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Journal Club

• Alcohol, Other Drugs, and Health Current
  Evidence
• JulyAugust 2008

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Featured Article

• A Prospective Study of Risk Drinking At Risk for
  What?
• Dawson DA, et al. Drug Alcohol Depend.
  200895(12)6272.

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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
  (n22,122) 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.

www.aodhealth.org
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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 3-year 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 20012002 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
• (n22,122)

Amount of Subjects
no risky drinking 60
lt1 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? (contd)

• 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 nicotine dependence
• alcohol dependence liver disease
• drug use divorced or separated
• drug dependence lost their drivers licenses
• tobacco use

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What Are the Results? (contd)

• Subjects who reported daily or near-daily risky
  drinking were more likely than subjects who
  reported no risky drinking to have

• alcohol abuse liver disease
• alcohol dependence divorced or separated
• tobacco use exhibited violent behavior
• nicotine dependence lost their drivers
  licenses

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How strong is the association between exposure
and outcomes? How precise is the estimate of
risk?
Occurrence of Adverse Outcomes Odds Ratios (95 CI) Odds Ratios (95 CI)
Occurrence of Adverse Outcomes Frequency of risky drinking Frequency of risky drinking
Occurrence of Adverse Outcomes 12 times per week daily or near-daily
alcohol abuse (n13,894) 3.29 (2.474.38) 3.93 (2.406.44)
alcohol dependence (n18,114) 2.69 (2.003.62) 7.23 (4.7511.00)
drug use (n15,018) 1.63 (1.192.24) 1.87 (1.212.88)
drug dependence (n20,669) 2.32 (1.304.14) 2.13 (0.994.59)
tobacco use (n10,418) 2.71 (1.754.18) 4.67 (2.1610.10)
nicotine dependence (n17,061) 1.77 (1.262.48) 3.03 (1.924.79)
any liver disease (n21,200) 2.78 (1.325.85) 4.76 (2.299.88)
divorce/separation (n11,665) 1.34 (0.882.02) 2.54 (1.504.28)
violent behavior (n21,313) 1.09 (0.781.54) 1.61 (1.052.47)
drivers license revoked (n21,313) 1.81 (1.302.54) 2.11 (1.383.22)
abuse of spouse (n11,665) 1.27 (0.871.85) 2.06 (1.223.46)
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www.aodhealth.org
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How strong is the association between exposure
and outcomes? How precise is the estimate of
risk? (contd)

• 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 (n22,122) 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 conse- quence
  associated with risky drinking were 23 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 liver disease
• alcohol dependence being divorced or separated
• tobacco use exhibiting violent behavior
• nicotine dependence losing a drivers license