Patterns and Factors Associated With Adherence to Lung Cancer Screening in Diverse Practice Settings.

Importance: For lung cancer screening to confer mortality benefit, adherence to annual screening with low-dose computed tomography scans is essential. Although the National Lung Screening Trial had an adherence rate of 95%, current data are limited on screening adherence across diverse practice settings in the United States. Objective: To evaluate patterns and factors associated with adherence to annual screening for lung cancer after negative results of a baseline examination, particularly in centralized vs decentralized screening programs. Design, Setting, and Participants: This observational cohort study was conducted at 5 academic and community-based sites in North Carolina and California among 2283 individuals screened for lung cancer between July 1, 2014, and March 31, 2018, who met US Preventive Services Task Force eligibility criteria, had negative results of a baseline screening examination (American College of Radiology Lung Imaging Reporting and Data System category 1 or 2), and were eligible to return for a screening examination in 12 months. Exposures: To identify factors associated with adherence, the association of adherence with selected baseline demographic and clinical characteristics, including type of screening program, was estimated using multivariable logistic regression. Screening program type was classified as centralized if individuals were referred through a lung cancer screening clinic or program and as decentralized if individuals had a direct clinician referral for the baseline low-dose computed tomography scan. Main Outcomes and Measures: Adherence to annual lung cancer screening, defined as a second low-dose computed tomography scan within 11 to 15 months after baseline screening. Results: Among the 2283 eligible individuals (1294 men [56.7%]; mean [SD] age, 64.9 [5.8] years; 1160 [50.8%] aged ≥65 years) who had negative screening results at baseline, overall adherence was 40.2% (n = 917), with higher adherence among those who underwent screening through centralized (46.0% [478 of 1039]) vs decentralized (35.3% [439 of 1244]) programs. The independent factor most strongly associated with adherence was type of screening program, with a 2.8-fold increased likelihood of adherence associated with centralized screening (adjusted odds ratio [aOR], 2.78; 95% CI, 1.99-3.88). Another associated factor was age (65-69 vs 55-59 years: aOR, 1.38; 95% CI, 1.07-1.77; 70-74 vs 55-59 years: aOR, 1.47; 95% CI, 1.10-1.96). Conclusions and Relevance: After negative results of a baseline examination, adherence to annual lung cancer screening was suboptimal, although adherence was higher among individuals who were screened through a centralized program. These results support the value of centralized screening programs and the need to further implement strategies that improve adherence to annual screening for lung cancer.

Rates of positive lung cancer screening examinations in academic versus community practice.

The benefits and harms of lung cancer screening reported in the National Lung Screening Trial (NLST) likely differ from those observed in academic and community settings. High rates of positive screening findings in the NLST led to the development of the Lung CT Screening Reporting and Data System (Lung-RADS) to standardize interpretation and reporting. We conducted a prospective observational study of lung cancer screening data from four lung cancer screening sites in North Carolina to compare prospective use of Lung-RADS in a real-world screened population versus Lung-RADS retrospectively applied to the NLST, and to determine if Lung-RADS assessment use differs in academic versus community settings. We included 4,037 screening examinations from 11/2014 to 12/2018 in academic and community sites and 75,126 NLST LDCT screening exams. On baseline screening exams, the proportion of positive LDCT exams was higher in community versus academic sites or the NLST (17.7% vs. 11.4% and 13.6%, P value <0.01). On subsequent screens, the proportion of positive exams was lowest in the NLST and higher in community and academic sites (5.9% vs. 12.7% and 11.6%, P value <0.01). After adjusting for age, race, sex, and smoking status, patients screened at academic versus community sites were 34% less likely to have a positive screen at baseline [adjusted odds ratio (aOR) =0.66; 95% confidence interval (95% CI): 0.51-0.86] but on subsequent examinations, there was no difference in academic versus community sites (aOR =0.91; 95% CI: 0.58-1.43). Our findings may be due to differences in radiologists' training or experiences or the availability of prior images for comparison.