Predictors of Successful Telephone Contact After Emergency Department-based Recruitment into a Multicenter Smoking Cessation Cohort Study

INTRODUCTION: Emergency department (ED) studies often require follow-up with subjects to assess outcomes and adverse events. Our objective was to identify baseline subject characteristics associated with successful contact at 3 time points after the index ED visit within a sample of cigarette smokers. METHODS: This study is a secondary analysis of a prospective cohort. We recruited current adult smokers at 10 U.S. EDs and collected baseline demographics, smoking profile, substance abuse, health conditions, and contact information. Site investigators attempted contact at 2 weeks, 3 months, and 6 months to assess smoking prevalence and quit attempts. Subjects were paid $20 for successful follow-up at each time point. We analyzed data using logistic and Poisson regressions. RESULTS: Of 375 recruited subjects, 270 (72%) were contacted at 2 weeks, 245 (65%) at 3 months, and 217 (58%) at 6 months. Overall, 175 (47%) were contacted at 3 of 3, 71 (19%) at 2 of 3, 62 (17%) at 1 of 3, and 66 (18%) at 0 of 3 time points. At 6 months, predictors of successful contact were: older age (adjusted odds ratio [AOR] 1.2 [95%CI, 0.99–1.5] per ↑10 years); female sex (AOR 1.7 [95%CI, 1.04–2.8]); non-Hispanic black (AOR 2.3 [95%CI, 1.2–4.5]) vs Hispanic; private insurance (AOR 2.0 [95%CI, 1.03–3.8]) and Medicare (AOR 5.7 [95%CI, 1.5–22]) vs no insurance; and no recreational drug use (AOR 3.2 [95%CI; 1.6–6.3]). The characteristics independently predictive of the total number of successful contacts were: age (incidence rate ratio [IRR] 1.06 [95%CI, 1.00–1.13] per ↑10 years); female sex (IRR 1.18 [95%CI, 1.01–1.40]); and no recreational drug use (IRR 1.37 [95%CI, 1.07–1.74]). Variables related to smoking cessation (e.g., cigarette packs-years, readiness to quit smoking) and amount of contact information provided were not associated with successful contact. CONCLUSION: Successful contact 2 weeks after the ED visit was 72% but decreased to 58% by 6 months, despite modest financial incentives. Older, female, and non-drug abusing participants were the most likely to be contacted. Strategies to optimize longitudinal follow-up rates, with limited sacrifice of generalizability, remain an important challenge for ED-based research. This is particularly true for studies on substance abusers and other difficult-to-reach populations.