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					    Journal Club

Alcohol and Health: Current Evidence
         July–August 2005



            www.alcoholandhealth.org   1
              Featured Article

 Screening for hazardous or harmful
      drinking using one or two
    quantity-frequency questions

Canagasaby A, Vinson DC. Alcohol Alcohol. 2005;40(3):208–213.



                      www.alcoholandhealth.org            2
    Study Objective

To compare the performances of
 brief screening tests to detect
     unhealthy alcohol use




          www.alcoholandhealth.org   3
                  Study Design
• Investigators screened…
  – 1537 emergency department patients with an acute
    injury,
  – 1151 emergency patients with a medical illness
  – 1112 randomly selected people contacted by telephone


• Researchers first asked each subject…
  – a question about alcohol consumption in a day
     (“When was the last time you had more than X drinks in
     1 day?” with X being 5 for men and 4 for women)

                        www.alcoholandhealth.org              4
            Study Design (cont.)
• They asked subjects who reported drinking >=6 drinks
  in the past year 2 standard questions about quantity and
  frequency of consumption:
   – the average number of drinks per occasion
   – the frequency of drinking (5-point ordinal scale from “less than
     once a month” to “almost every day”)

• Diagnostic interviews (the Diagnostic Interview
  Schedule) determined the presence of an alcohol use
  disorder (based on the Diagnostic and Statistical Manual
  of Mental Disorders, DSM IV).
• Validated calendar methods determined drinking
  amounts.
                          www.alcoholandhealth.org                  5
   Assessing Validity of an
Article about Diagnostic Tests

  • Are the results valid?

  • What are the results?

  • How can I apply the results to patient
    care?

                www.alcoholandhealth.org     6
    Are the Results Valid?
• Did clinicians face diagnostic uncertainty?

• Was there a blind comparison with an
  independent gold standard applied similarly
  to the treatment group and the control
  group?

• Did the results of the test being evaluated
  influence the decision to perform the
  reference standard?
                 www.alcoholandhealth.org       7
   Did clinicians face diagnostic
            uncertainty?

• Because of the nature of screening (testing
  people regardless of symptoms of the target
  disorder), there was inherent diagnostic
  uncertainty.
  – Diagnoses were not known prior to
    testing.


                www.alcoholandhealth.org        8
     Was there a blind comparison with an
independent gold standard applied similarly to
  the treatment group and the control group?

   • There was a comparison with a “gold” (reference)
     standard applied to all subjects.

      – The reference standard was a structured
        interview conducted by trained research staff.

   • Staff was not blinded to the answers provided by
     subjects.


                     www.alcoholandhealth.org            9
  Did the results of the test being
 evaluated influence the decision to
  perform the reference standard?
• No:
  – Everyone completed the reference standard.
  – However, the diagnostic reference standard
    (though well-accepted and extensively
    validated) defines people who deny having
    had >=6 drinks in the past year as having no
    alcohol use diagnosis.

                 www.alcoholandhealth.org     10
   What Are the Results?

• What likelihood ratios were associated
  with the range of possible test results?




               www.alcoholandhealth.org      11
What likelihood ratios were associated
with the range of possible test results?

 • At a specificity of at least 70%, the single
   question about alcohol consumption in a
   day had the best sensitivity.

 • A response of “in the last 3 months” was
   associated with the following likelihood
   ratios:
    – For women: positive test 3.6; negative test 0.2
    – For men: positive test 2.8; negative test 0.2
                   www.alcoholandhealth.org             12
     How Can I Apply the Results to
            Patient Care?

• Will the reproducibility of the test result and its
  interpretation be satisfactory in my clinical setting?

• Are the results applicable to the patients in my
  practice?

• Will the results change my management strategy?

• Will patients be better off as a result of the test?

                     www.alcoholandhealth.org        13
Will the reproducibility of the test
  result and its interpretation be
satisfactory in my clinical setting?

• The interpretation is not difficult.

• Reproducibility is uncertain since the
  screening questions were asked by trained
  research staff.

• The question is not difficult to ask and
  training is not required; however, patients
  may be less forthcoming with their own
  caregivers.
                 www.alcoholandhealth.org       14
 Are the results applicable to the
     patients in my practice?


• The results appear to have broad
  applicability since screening occurred in
  emergency and general population
  samples.




               www.alcoholandhealth.org       15
      Will the results change my
       management strategy?

• Results could change patient management.

  – Like previous studies, this study found that
    the single alcohol screening question has
    excellent sensitivity and specificity.

  – Current practice is to use questions that are
    not validated, or more rarely, to use 4- or
    10-item validated screening questionnaires.
                  www.alcoholandhealth.org      16
    Will the results change my
   management strategy? (cont.)

• Use of a single screening question appears
  to be valid and much more likely to be
  employed in busy clinical practice.

• In a new guide for clinicians, the National
  Institute on Alcohol Abuse and Alcoholism
  recommends a similar single question for
  alcohol screening.

                 www.alcoholandhealth.org       17
     Will patients be better off as
          a result of the test?

• Yes; patients will benefit from this approach
  to screening.
  – Screening followed by brief intervention, when
    indicated, in primary care settings has proven
    efficacy for decreasing risky drinking in
    nondependent drinkers.
  – Patients identified by screening who have alcohol
    dependence may also benefit from referral to
    specialty treatment.
                   www.alcoholandhealth.org             18
Summary/Clinical Resolution
• A single question asking about the last time a
  patient drank excessively can detect
  unhealthy alcohol use including risky drinking
  and alcohol use disorders.

• The only methodological caveat is that the
  full diagnostic reference standard used in this
  study was not completed in very light
  drinkers.
  – However, the caveat is a small one since it is unlikely that
    many people who report drinking <6 drinks per year would
    have unhealthy alcohol use.
                       www.alcoholandhealth.org                    19

				
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