ABSTRACT: Hospitalization provides an opportunity for smokers to quit, but tobacco-cessation interventions started in hospital must continue after discharge to be effective. This study aimed to improve the scalability of a proven effective post-discharge intervention by incorporating referral to a telephone quitline, a nationally available cessation resource.A three-site RCT compared Sustained Care, a post-discharge tobacco-cessation intervention, with Standard Care among hospitalized adult smokers who wanted to quit smoking and received in-hospital tobacco-cessation counseling.A total of 1,357 daily smokers admitted to three hospitals were enrolled from December 2012 to July 2014.Sustained Care started at discharge and included automated interactive voice response telephone calls and the patient's choice of cessation medication for 3 months. Each automated call advised cessation, supported medication adherence, and triaged smokers seeking additional counseling or medication support directly to a telephone quitline. Standard Care provided only medication and counseling recommendations at discharge.Biochemically confirmed past 7-day tobacco abstinence 6 months after discharge (primary outcome) and self-reported tobacco abstinence and tobacco-cessation treatment use at 1, 3, and 6 months and overall (0-6 months). Analyses were done in 2015-2016.Smokers offered Sustained Care (n=680), versus those offered Standard Care (n=677), did not have greater biochemically confirmed abstinence at 6 months (17% vs 16%, p=0.58). However, the Sustained Care group reported more tobacco-cessation counseling and medication use at each follow-up and higher rates of self-reported past 7-day tobacco abstinence at 1 month (43% vs 32%, p<0.0001) and 3 months (37% vs 30%, p=0.008). At 6 months, the difference narrowed (31% vs 27%, p=0.09). Overall, the intervention increased self-reported 7-day abstinence over the 6-month follow-up (relative risk, 1.25; 95% CI=1.10, 1.40; p=0.0006).A 3-month post-discharge smoking-cessation intervention for hospitalized smokers who wanted to quit did not increase confirmed tobacco abstinence at 6 months but did increase self-reported abstinence during the treatment period (3 months). Real-time linkage of interactive voice response calls to a quitline, done in this trial to increase scalability of a previously proven cessation intervention, demonstrated short-term promise but did not sustain long-term intervention effectiveness.This study is registered at www.clinicaltrials.gov NCT01714323.