Related Experiment Video
Updated: Apr 24, 2026

Use of Electromagnetic Navigational Transthoracic Needle Aspiration E-TTNA for Sampling of Lung Nodules
Published on: May 23, 2015
National Lung Screening Trial findings by age: Medicare-eligible versus under-65 population
Background:
The NLST (National Lung Screening Trial) showed reduced lung cancer mortality in high-risk participants (smoking history of ≥30 pack-years) aged 55 to 74 years who were randomly assigned to screening with low-dose computed tomography (LDCT) versus those assigned to chest radiography. An advisory panel recently expressed reservations about Medicare coverage of LDCT screening because of concerns about performance in the Medicare-aged population, which accounted for only 25% of the NLST participants.
Objective:
To examine the results of the NLST LDCT group by age (Medicare-eligible vs. <65 years).
Design:
Secondary analysis of a group from a randomized trial (NCT00047385).
Setting:
33 U.S. screening centers.
Patients:
19 612 participants aged 55 to 64 years (under-65 cohort) and 7110 participants aged 65 to 74 years (65+ cohort) at randomization.
Intervention:
3 annual rounds of LDCT screening.
Measurements:
Demographics, smoking and medical history, screening examination adherence and results, diagnostic follow-up procedures and complications, lung cancer diagnoses, treatment, survival, and mortality.
Results:
The aggregate false-positive rate was higher in the 65+ cohort than in the under-65 cohort (27.7% vs. 22.0%; P < 0.001). Invasive diagnostic procedures after false-positive screening results were modestly more frequent in the older cohort (3.3% vs. 2.7%; P = 0.039). Complications from invasive procedures were low in both groups (9.8% in the under-65 cohort vs. 8.5% in the 65+ cohort). Prevalence and positive predictive value (PPV) were higher in the 65+ cohort (PPV, 4.9% vs. 3.0%). Resection rates for screen-detected cancer were similar (75.6% in the under-65 cohort vs. 73.2% in the 65+ cohort). Five-year all-cause survival was lower in the 65+ cohort (55.1% vs. 64.1%; P = 0.018).
Limitation:
The oldest screened patient was aged 76 years.
Conclusion:
NLST participants aged 65 years or older had a higher rate of false-positive screening results than those younger than 65 years but a higher cancer prevalence and PPV. Screen-detected cancer was treated similarly in the groups.
Primary Funding Source:
National Institutes of Health.
Related Concept Videos
Statistical Methods for Analyzing Epidemiological Data
Pharmacokinetics in Geriatric Patients: Effect of Age on Drug Excretion
Pulmonary Function Tests
Pulmonary Function Tests are crucial diagnostic tools for assessing respiratory function, particularly in patients with chronic respiratory disorders. They comprehensively evaluate lung volumes, ventilatory function, breathing mechanics, diffusion, and gas exchange. These tests help diagnose pulmonary diseases and play a significant role in monitoring disease progression, evaluating disability, and assessing response to therapy.
PFTs involve using a spirometer, a...

