Table 1.
Time Horizon | Life Expectancy | Quality-Adjusted Life Expectancy | ||
---|---|---|---|---|
CT | Radiography | CT | Radiography | |
life-yr | QALY | |||
Within trial | 5.7846 | 5.7775 | 4.3390 | 4.3351 |
Participants with lung cancer | 4.9013 | 4.6029 | 3.5603 | 3.3596 |
Participants without lung cancer† | 5.8228 | 5.8228 | 4.3728 | 4.3728 |
Lifetime | 14.7386 | 14.7071 | 10.9692 | 10.9491 |
Participants with lung cancer | 8.4792 | 6.8479 | 6.0521 | 4.8981 |
Participants without lung cancer† | 15.0097 | 15.0103 | 11.1821 | 11.1825 |
Life-years were discounted at 3% and are defined as follows: within-trial life-years were calculated from the date of randomization to the date of death if the patient was deceased; to December 31, 2009, if the patient was alive; or to the latest date on which the patient was known to be alive if data on vital status were missing on December 31, 2009. For participants not known to be deceased by that date, beyond-trial life-years were estimated on the basis of the participants’ age on the date they were last known to be alive, sex, smoking status at study entry, and lung-cancer stage, if any, with the use of 2009 U.S. Life Tables18 adjusted for smoking status and stage-specific annual probabilities of dying from lung cancer. For further details see Sections 3 and 4 in the Supplementary Appendix. The results for participants who underwent no screening were assumed to be the same as for those who underwent radiographic screening.
For participants without lung cancer, outcomes were assumed to be the same for those who underwent CT screening and those receiving radiographic screening except for an adjustment for the occurrence of radiation-induced lung cancer after the trial.