Secondary analysis of a randomized clinical trial of very low nicotine cigarettes: Outcomes across social and demographic groups.

Abstract

To examine whether the impact of a nicotine reduction standard (NRS) varies by socio-demographics. Secondary analysis of a 12-week trial (2018-2022) with 438 people who smoke (PWS) comparing very low nicotine content (VLNC) vs. normal nicotine content (NNC) cigarettes. Moderation by education, race, and age on cigarettes per day (CPD), smoke-free days, and biomarkers (CEMA, NNAL) was assessed using interaction models. For race and education, interaction tests for moderation were not significant (ps > 0.05). In subgroup analyses, VLNC condition reduced CPD and biomarkers and increased smoke-free days with the following exception: no difference in CEMA was observed by condition among those of lower education (Geometric mean ratio [GMR] = 0.72, 95 % confidence interval [CI] = 0.39, 1.33). For age, multiple interaction tests were significant. In subgroup analyses, older but not younger adults, had no VLNC vs. NNC differences for CEMA (GMR: 0.85 [CI = 0.51, 1.41] vs 0.47 [CI = 0.35, 0.62]) or smoke-free days (rate ratio: 1.85 [CI = 0.63, 5.55] vs 5.85 [CI = 3.12, 10.89]). Age and potentially education moderate NRS effects among PWS. Targeted support for older adults and those with lower education may maximize NRS benefits. NCT03272685.