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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