Probing effect modification by socioeconomic status in associations between blood biomarkers of neuropathology and cognitive outcomes in the United States and India.

Although smoking prevalence among US adults has decreased to 9.9% in 2024, the prevalence of smoking among people experiencing homelessness is greater than 70%. Tobacco-caused chronic diseases are the leading causes of morbidity and mortality among adults experiencing homelessness, highlighting a need for effective smoking cessation interventions. People experiencing homelessness face barriers to cessation; these barriers do not hinder quit attempts, but they reduce the likelihood of successful quitting. The quit ratio (former to ever smoking—a marker of successful quitting) is 9% to 13% among people experiencing homelessness compared with 60% in the general population. Limited access to health care and tobacco treatment services, as well as high rates of co-occurring psychiatric and substance use disorders, hinder cessation efforts. Clinical trials among adults experiencing homelessness that have used guideline-recommended tobacco treatment of behavioral counseling and pharmacotherapy have demonstrated modest abstinence rates (9%-17%) at a 6-month follow-up. These trials show that while behavioral counseling and pharmacotherapy are essential, additional treatment approaches may be necessary to increase the efficacy of cessation among adults experiencing homelessness. Intervention trials that have used contingency management (CM) in addition to behavioral counseling and pharmacotherapy have yielded higher abstinence rates in this population (22%-48% at 4-week follow-up) than those without CM.