ABSTRACT: BACKGROUND:Emergency department (ED) patients have high rates of risky alcohol use, and an ED visit offers an opportunity to intervene. ED-based screening, brief intervention, and referral to treatment (SBIRT) reduces alcohol use and health care costs. Mobile health (mHealth) interventions may expand the impact of SBIRTs but are understudied in low-resource ED populations. OBJECTIVE:The objective of this study was to assess the feasibility of and patient satisfaction with a text-based mHealth extension of an ED screening program to reduce risky alcohol use in low-income, urban patients. METHODS:Research assistants screened a convenience sample of ED patients in person for risky alcohol use via the Alcohol Use Disorders Identification Test (AUDIT). Patients who reported AUDIT scores ?8 and <20 were informed of their AUDIT score and risk. RAs invited patients with SMS text message-capable phones to receive mROAD (mobilizing to Reduce Overuse of Alcohol in the ED), an SMS text message-based extension of the ED screening program. mROAD is a 7-day program of twice-daily SMS text messages based on the National Institutes of Health's Rethinking Drinking campaign. Participants were allocated to a control group (daily sham text messages without specific guidance on behaviors, such as "Thanks for taking part!") or to the mROAD intervention group. Patients were interviewed at 30 days to assess acceptability, satisfaction, and changes in drinking behavior. Satisfaction was examined descriptively. Pre and post measurements of drinking behaviors and motivation were compared, as were differences in change scores between the intervention arms. RESULTS:Of 1028 patients screened, 95 (9.2%) exhibited risky alcohol use based on AUDIT, and 23/95 (24%) of those patients did not own an SMS text messaging-capable phone; this left 72/95 (76%) eligible patients. Among eligible participants, 48/72 (67%) agreed to enroll; 31/48 (65%) achieved follow-up (18/24 (75%) in the intervention group and 13/24 (55%) in the control group). Participants who completed follow-up reported high satisfaction. Changes in behavior were similar between the arms. Overall, the number of drinking days reported in the prior 30 days decreased by 5.0 (95% CI 1.7-8.3; P=.004), and the number of heavy drinking days decreased by 4.1 (95% CI 1.0 to 7.15, P=.01). Patients reported an 11-point increase (95% CI 2.6-20, P=.01, 10% overall increase) in motivation to change alcohol use via the Change Questionnaire. The were no statistical differences in drinking days, heavy drinking days, or motivation to change between the arms. CONCLUSIONS:The mROAD trial was feasible. Over three-quarters of ED patients with risky alcohol use owned a text message-capable phone, and two-thirds of these patients were willing to participate; only 1 patient opted out of the intervention. Although 35% of patients were lost to follow-up at 30 days, those patients who did follow up had favorable impressions of the program; more than 90% reported that SMS text messages were a "good way to teach," and 89% of intervention arm participants enjoyed the program and found that the messages were motivating. Both the mROAD and sham message groups showed promising changes in alcohol use and motivation to change. mROAD is a feasible intervention that may reduce rates of risky alcohol use in ED patients. TRIAL REGISTRATION:ClinicalTrials.gov NCT02158949; https://clinicaltrials.gov/ct2/show/NCT02158949.