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. Author manuscript; available in PMC: 2022 Aug 1.
Published in final edited form as: Lancet Respir Med. 2021 Apr 12;9(8):840–850. doi: 10.1016/S2213-2600(21)00022-9

Figure 3: Exhaled CO and cigarettes smoked per day.

Figure 3:

(A) Exhaled CO over time. (B) Number of cigarettes smoked per day over time (average of the previous 7 days). ENDS=electronic nicotine delivery system. ppm=parts per million. Analyses were unadjusted and represent estimated means with 95% CI following multiple imputation. Filled symbols indicate a significant difference relative to week 0 within that group (Bonferroni correction α=0·0063; eight comparisons with week 0 were done for each group). Six between-group comparisons were done at each timepoint (Bonferroni correction α=0·0083); asterisks indicate a significant difference relative to the cigarette substitute group for that group at that timepoint; number signs indicate a significant difference relative to the 0 mg/mL group for that group at that timepoint.