Primary prevention data highlight the risk of exposure to environmental tobacco smoke, also called passive smoking or secondhand smoke, on stroke rates in nonsmokers. The most recent meta-analysis identified that environmental tobacco smoke exposure compared with no exposure can increase the overall risk of stroke Other reports identify comparative rates of an OR of an OR of 1.82 (95% and an RR of 1.23 (95% RR estimates were similar when ever exposure rather than current expo- sure or total rather than spousal exposure was used, and when dose-response estimates were pooled, the combined RR for the highest expo- Data from the US National Health and Nutrition Examination Surveys identified that high expo- sure to environmental tobacco smoke for stroke survivors was associated with an adjusted HR for all-cause mortality of 1.72 (95% CI, 1.02 2.91), with a dose-dependent relationship No trials of interventions to reduce exposure to environmental tobacco smoke as a stroke secondary prevention strategy were identified. 4.1.4. Substance Use Recommendations for Substance Use Referenced studies that support recommendations are summarized in online Data Supplements 9 and 10. COR LOE Recommendations Patients with ischemic stroke or TIA who drink >2 alcoholic drinks a day for men or >1 alco- holic drink a day for women should be coun- seled to eliminate or reduce their consumption of alcohol to reduce stroke risk.141,161 163 In patients with stroke or TIA who use stimulants (eg, amphetamines, amphetamine derivatives, cocaine, or khat) and in patients with infective endocarditis (IE) in the context of intravenous drug use, it is recommended that health care providers inform them that this behavior is a health risk and counsel them to stop. In patients with stroke or TIA who have a substance use disorder (drugs or alcohol), specialized services are recommended to help manage this dependency. 