INTRODUCTION: While previous research has examined misperceptions related to Natural American Spirit (NAS), a premium cigarette brand using 'natural'-themed marketing, the longitudinal relationship between NAS-related harm beliefs and switching to NAS has not been established. METHODS: Using data from the PATH study, we modelled the longitudinal relationship between (1) brand switching and subsequent belief that one's own brand might be less harmful than other brands (Waves 1-5)
(2) belief that organic and/or additive-free tobacco products are less harmful and subsequent brand switching (Waves 3-5)
and (3) belief that some types of cigarettes are less harmful and subsequent brand switching (Waves 3-5) for NAS and two leading comparator brands (Camel and Marlboro). RESULTS: Among people who did not think their prior brand might be less harmful, switching to NAS or maintaining NAS preference increased the odds of believing one's own brand might be less harmful (aOR 19.4
95% CI: 15.19, 24.8
aOR 6.1
95% CI: 4.23, 8.67, respectively). Prior belief that organic and additive-free tobacco products were less harmful increased the odds of switching to (aOR 2.5
95% CI: 1.68, 3.74) and decreased the odds of switching away (0.57
955 CI: 0.36, 0.92) from NAS in the subsequent wave. Parallel analyses for Marlboro/Camel were largely null or in the opposite direction. CONCLUSIONS: NAS use may maintain or shape new beliefs that the brand may be less harmful than other brands
holding pre-existing beliefs about the relative harm of some tobacco products may increase risk for NAS use.