1. www.aodhealth.org1 Journal Club Alcohol, Other Drugs, and Health: Current Evidence May–June 2010

2. www.aodhealth.org2 Featured Article β-Blockers for Chest Pain Associated with Recent Cocaine Use Rangel C, et al. Arch Intern Med. 2010;170(10):874 –9.

3. www.aodhealth.org3 Study Objective To determine whether β-blockers, which are known to decrease adverse events after myocardial infarction but are thought to be potentially harmful following recent cocaine use, are safe for patients with cocaine- related chest pain.

4. www.aodhealth.org4 Study Design Retrospective cohort study of consecutive patients admitted to San Francisco General Hospital with chest pain and cocaine-positive urine test results between January 2001 and December 2006 (N=331). Mortality data were collected from the Department of Health & Human Services National Death Index. The primary predictor was receipt of a β-blocker in the Emergency Department (ED). Secondary predictors were receipt of any β-blocker during post-ED hospitalization and discharge on a β- blocker regimen.

5. www.aodhealth.org5 Study Design (cont’d) The primary outcome measure was death. Secondary outcomes were: –peak troponin level in the first 24 hours of admission –ventricular fibrillation or ventricular tachycardia requiring defibrillation –need for intubation –need for vasopressor agents

6. www.aodhealth.org6 Assessing Validity of an Article About Harm Are the results valid? What are the results? How can I apply the results to patient care?

7. www.aodhealth.org7 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?

8. www.aodhealth.org8 Did the investigators demonstrate similarity in all known determinants of outcomes? Did they adjust for differences in the analysis? Yes. –Covariables were included in the multivariable model based on convention (e.g., age and sex) or if they were associated with both the predictor and outcome with a p-value of <.20. –Analyses were adjusted for the following: –age, race, and sex –history of end-stage renal disease –outpatient angiotensin- converting enzyme inhibitor use –outpatient angiotensin- receptor blocker use –troponin level –discharge on a calcium channel blocker regimen

9. www.aodhealth.org9 Were exposed patients equally likely to be identified in the groups?  Yes. –Exposure for all subjects was documented in paper medical charts and in electronic medical records.

10. www.aodhealth.org10 Were the outcomes measured in the same way in the groups being compared?  Yes. –The National Death Index was used to determine deaths (primary outcome) that occurred after admission among all subjects. –Data on secondary outcomes were obtained from paper medical charts and the electronic medical record.

11. www.aodhealth.org11 Was follow-up sufficiently complete? Yes. –Information was available from the National Death Index for 317 of 331 subjects (96%) at 5-year follow-up.

12. www.aodhealth.org12 What are the Results? How strong is the association between exposure and outcomes? How precise is the estimate of the risk?

13. www.aodhealth.org13 How strong is the association between exposure and outcome? How precise is the estimate of the risk? The researchers were not able to detect an association between receipt of a β-blocker and incident mortality: –received a β-blocker in the ED (hazard ratio [HR], 0.97; 95% CI, 0.53–1.79). –received a β-blocker during hospitalization (HR, 0.81; 95% CI, 0.44 –1.48). –discharged on a β-blocker regimen (HR, 0.90; 95% CI, 0.47– 1.71). Discharge on a β-blocker regimen was associated with a significant (70%) reduction in the risk of cardio- vascular death (HR, 0.29; 95% CI, 0.09–0.98).

14. www.aodhealth.org14 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?

15. www.aodhealth.org15 Were the study patients similar to the patients in my practice? Subjects were predominantly black males and were approximately 50 years of age. More than 80% were current smokers.

16. www.aodhealth.org16 Was the duration of follow-up adequate? Yes. –Five years is an adequate period of time for follow-up of cardiovascular mortality and effects of β-blocker exposure.

17. www.aodhealth.org17 What was the magnitude of the risk? The researchers were unable to determine whether β-blockers placed patients with cocaine-related chest pain at increased risk of mortality: –received a β-blocker in the ED (hazard ratio [HR], 0.97; 95% CI, 0.53-1.79). –received a β-blocker during hospitalization (HR, 0.81; 95% CI, 0.44-1.48). –discharged on a β-blocker regimen (HR, 0.90; 95% CI, 0.47-1.71).

18. www.aodhealth.org18 Should I attempt to stop the exposure? The findings do not support limiting β- blocker treatment in patients with cocaine- related chest pain due to concerns over unopposed alpha-adrenergic stimulation. The findings are limited by the following: –lack of blinding. –potential surveillance bias (only patients with cocaine-metabolite–positive urine tests were included in the study).