The number needed to treat (NNT) is the average number of patients who need to be treated for one patient to benefit with active treatment versus with placebo treatment. In our study, the NNT for NRT was 2.9 for fast metabolizers (70.7% of the sample) vs. >1000 for slow metabolizers (29.3% of the sample). The NNT was 4.2 across all individuals regardless of their genotype status, supporting the established effect of NRT. However, the NNT varied widely depending on the individual’s CYP2A6 genotype (Figure S2).
