Transcript Related Journal Club Presentation

Journal Club
Alcohol, Other Drugs, and Health: Current Evidence
January–February 2014
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Featured Article
Alcohol consumption and risk
of melanoma and nonmelanoma skin cancer in the
Women’s Health Initiative
Kubo JT, et al. Cancer Causes Control. 2014;25(1):1–10.
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Study Objective
• To determine whether there is a relationship
between alcohol consumption and the risk of
developing malignant melanoma (MM) and nonmelanoma skin cancer (NMSC) among women.
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Study Design
• Prospective cohort of 59,575 white,
postmenopausal women (mean age 63.6).
• Data was collected from the Women's Health
Initiative (WHI) Observational Study (OS).
• Researchers used Cox proportional hazards
models and logistic regression techniques to
determine risk of MM and NMSC.
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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?
• No, these were adjusted for in the
statistical analyses.
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Did they adjust for differences in the analysis?
• As skin cancer is rare in other ethnic groups, the
investigators excluded non-white participants.
Their analysis adjusted for other determinants of
skin cancer including age, sun exposure and skin
type.
• There were additional adjustments for education,
smoking, BMI, physical activity, having a last
medical visit within 1 year of study baseline,
insurance status, having a current care provider,
history of NMSC, and history of melanoma.
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Were exposed patients equally likely
to be identified in the groups?
• Yes.
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Were the outcomes measured in the
same way in the groups being compared?
• Yes.
– The two primary outcomes were time
to incident melanoma (adjudicated)
and occurrence of incident NMSC (selfreport) during follow-up.
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Was follow-up sufficiently complete?
• Unclear.
– There is no data presented to
determine whether there was
differential follow-up by alcohol
exposure category.
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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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How strong is the association between
exposure and outcome?
How precise is the estimate of the risk?
• Modeling alcohol servings per week as a
continuous variable results in a HR of 1.16
(1.06, 1.27) for each seven additional servings
for MM and an OR of 1.08 (1.05, 1.11) for each
seven additional servings for NMSC.
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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 participants were white postmenopausal women, 50 to 79 years of
age.
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Was the duration of follow-up adequate?
• Yes
– Mean follow-up time was 10.2 years.
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What was the magnitude of the risk?
• Participants who consumed ≥7 standard drinks in a
week had a higher hazard of MM (hazard ratio [HR],
1.64), and a higher risk of NMSC (odds ratio [OR],
1.23) compared with non-drinkers.
• Compared with non-drinkers, a preference for either
white wine or liquor was associated with an
increased hazard of MM (white wine [HR, 1.52];
liquor [HR, 1.65]), and risk of NMSC (white wine [OR
1.16], liquor [OR 1.26]).
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Should I attempt to stop the exposure?
• There are considerable observational
epidemiologic data suggesting that alcohol
consumption may relate to an increase in the
risk of MM and NMSC. As mechanisms are
not known, there is still concern that much of
this association may relate to residual
confounding by ultraviolet sun exposure.
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