To the Editor Dr Ebbert and colleagues1 tested the efficacy of varenicline for cessation among those willing to reduce but not quit smoking. They noted abstinence rates for the primary efficacy end point of 32.1% for the varenicline group vs 6.9% for the placebo group, with expired breath carbon monoxide levels of 10 ppm or less indicating abstinence.
Cropsey KL, Clark CB, Hendricks PS. Varenicline for Smoking Reduction Prior to Cessation. JAMA. 2015;313(22):2284-2285. doi:10.1001/jama.2015.4972