explored the possibility that lung cancer diagnoses prior to the follow-up questionnaire biased our estimates by excluding these individuals from our models in a sensitivity analysis. Lastly, we conducted a sensitivity analysis among only participants with complete follow-up questionnaire data (n = 5,530), without allowing for any substitution of baseline data for covariates. In a small number of instances of missing follow-up data for covariates, individual values were imputed based on baseline values; such substitutions occurred for race, age at smoking initiation, cigarettes per day, pack-years, and smoking duration (years smoked).
