Risk perception (RP) is central to smokers’ decision to switch to smoke-free tobacco and nicotine products (TNP).

This study assessed temporal trends in the health RP of a novel heated tobacco product, IQOS™, relative to cigarettes, among current IQOS™ users.

The analyses included repeated cross-sectional data from online surveys in Germany (n=2536, years 2018–19), Italy (n = 2457, years 2018 - 19), and Japan (n = 5044, years 2016 - 17, 2017 - 18, and 2018 - 19) among a random sample of current adult IQOS™ users from local registers of IQOS™ users. The health RP of cigarettes and IQOS™ were assessed using the ABOUT™–Perceived Risk instrument. The score ranged from zero, indicating no perceived risk, to 100, indicating very high perceived risk. Relative RP of IQOS™ to cigarettes (RP_{Cigarettes-IQOS}) was computed as the difference in absolute RP scores of cigarettes minus IQOS™.

After adjustment for covariates (sex, age group, IQOS™ use pattern (exclusive vs. dual) and intensity), the relative RP_{Cigarettes-IQOS} was higher in 2018 than in 2019 (β-coefficient of 0.93; standard error, 0.33; P=0.005). This was driven by an increase in the RP of IQOS™ over time in Italy (2018: mean RP score = 42.6 [95 % CI, 41.6–43.5]; 2019: 44.4 [43.4–45.4]) and Japan (2017: 44.0 [43.1–44.9); 2018: 45.9 [45.2–46.7]; 2019: 48.6 [47.9–49.4]), while the RP of cigarettes remained stable.

The relative RP of IQOS™ decreased over time, driven by an increase in the RP of IQOS™, in agreement with epidemiological studies indicating a temporal reduction in the relative RP of smoke-free TNPs. Continued surveillance of the RP of novel TNPs is warranted to inform effective TNP risk communication and ensure that adult smokers who would otherwise continue to smoke understand the relative risks of novel TNPs.