Reasons for Exclusion from a Smoking Cessation Trial: An Analysis by Race/Ethnicity

The exclusion criteria of tobacco cessation randomized clinical trials (RCTs) may have unintended consequences on inclusion and cessation disparities. We examined racial/ethnic differences in: a) exclusion from a group-based cessation RCT; and b) reasons for exclusion.

Quasi-experimental. Inclusion criteria were self-identification as African American/Black, non-Hispanic White, or Hispanic (any race), adults, minimum five cigarettes/day or carbon monoxide reading of ≥ 8 parts per million (ppm), interest in quitting, and spoke/read English. Data were obtained from a parent trial, which is ongoing and will be completed in 2019. Analyses for our present study on participant screening and enrollment were conducted in 2018.

Study ineligibility, and reasons for exclusion (contraindications for nicotine patch use, serious mental illness [SMI, eg, bipolar disorder or schizophrenia], alcohol dependence or illicit drug use, current tobacco treatment, attendance barriers [eg, transportation], and other concerns [eg, aggressive, intoxicated, disruptive, visibly ill]).

Of 1,206 individuals screened, 36% were ineligible. The most frequent reasons were SMI (28%), alcohol dependence or drug use (10%), and attendance barriers (7%). Ineligibility was greater among African Americans (42%) and Hispanics (37%), compared with Whites (24%; P<.001). Compared with African Americans and Hispanics, Whites were more likely to be excluded for single reasons, including attendance barriers, and medical conditions (P<.05). African Americans were more than twice as likely as Whites to be excluded for 3 or more reasons (12% vs 5% respectively, P<.05).

A notable proportion of smokers were ineligible for this RCT, with SMI as the greatest single cause. Racial/ethnic minorities were more likely to be excluded, with African Americans deemed ineligible for multiple reasons. Findings have implications for RCT generalizability, addressing tobacco disparities and health equity.