At least three additional studies have explored the cost-effectiveness of annual LDCT screening, two of which presented their results in quality-adjusted life years (QALYs). A separate study by Marshall et al,17using the same assumptions about effectiveness described previously, estimated that for an annual screening for 5 years, the incremental cost-effectiveness per QALY was $19,533. Sensitivity analyses considered a 1-year decrease in survival to account for potential confounding by lead-time and overdiagnosis biases, yielding a cost-effectiveness ratio of $50,473 per QALY. Taking a slightly different approach, Mahadevia et al18 stratified individuals by smoking status: continuing, quitting, and former (those who had quit > 5 years earlier). Expected diagnoses and mortality rates were obtained from SEER, and the model was sensitive to the degree of stage shift, adherence to screening, degree of length or overdiagnosis bias, cost of CT, and anxiety about indeterminate nodules. For current smokers, effectiveness was modeled as a 50% stage shift with a resulting 13% decrease in lung cancer mortality during the first 20 years. The incremental cost-effectiveness per QALY gained was $116,300 for current smokers. For quitting and former smokers, the corresponding projections were $558,600 and $2,322,700 per QALY, respectively. In sensitivity analyses, only improbably favorable conditions generated costs within the range of the estimates provided by other studies: $42,500 for current, $75,300 for quitting, and $94,400 for former smokers. It should be noted, however, that this study examined costs over a longer time horizon and considered numerous variables in its baseline model that the other cost-effectiveness studies elected to omit.