The Effects of Pictorial Health Warning Label on Waterpipe (Low- and High-Frequency) Smokers' Experiences, Toxicant Exposures, and Puffing Behavior.

Background: Pictorial health warning label (PHWL) is an effective risk communication measure among cigarette smokers. However, there is a lack of knowledge regarding the effect of PHWL on low- and high-frequency waterpipe (WP) smokers. This study examined the effects of PHWL on puffing behavior, subjective experiences, and toxicant exposures among low- and high-frequency WP smokers in the United States (US). Methods: Sixty current (past-month) WP smokers (low-frequency; n = 30 and high-frequency; n = 30) completed two 45-min ad libitum WP smoking sessions in a cross-over design study (WP with no-PHWL vs. WP with PHWL). We compared the mean differences of puff topography, expired carbon monoxide (eCO), plasma nicotine concentration, and subjective experiences between the two smoking groups. Results: Mean age of low-frequency smokers was 21.5 years and high-frequency smokers was 21.3 years. Compared to high-frequency, low-frequency smokers had significant reduction in average total smoking time [mean difference (SD) = −7.6 (10.2) min vs. −2.6 (6.7) min, p = 0.03] and number of puffs [mean difference (SD) = −33.37 (70.7) vs. −0.70 (29.2), p = 0.02] following exposure to PHWL compared to no-PHWL condition. Post-session subjective experiences were lower among high-frequency smokers compared to low-frequency smokers following smoking WP with PHWL compared to the no-PHWL session (puff liking −1.2 vs. −0.5; puff satisfaction −1.0 vs. −0.3; craving reduction −0.5 vs. 1.2) (p < 0.05 for all). Conclusion: Our findings indicate that placing PHWL on the WP device may be a promising strategy with differential effectiveness among WP smokers: low-frequency (reduce puffing behaviors) and high-frequency (reduce smoking experience). [ABSTRACT FROM AUTHOR]