Sample Size
The sample size was based on a 2-tail significance test with 80% power and a 15% attrition rate (from our previous studies at our center). We referenced smoking abstinence rates from available trials that did not enroll a clinical population, and showed an adaptive treatment rate of 39.7%, and standard treatment of 23.4% and an absolute difference between groups of 16.3 percentage points. The study was initially designed to have sample size of 300 participants but was stopped early due to COVID-19 pandemic–related restrictions on in-person visits. After restrictions were lifted, funding was no longer available for the study, and analyses were conducted on the enrolled sample.