Background: With the increased utilization of chest computed tomography, incidental pulmonary nodules (PN) are frequently encountered in clinical practice. While several professional guidelines exist on PN management, limited evidence exists regarding the evaluation of PN in clinical practice. We examined the incidence of lung cancer (LC) and utilization of invasive procedures in patients with PNs using real-world data. Methods: We conducted a retrospective cohort study using longitudinal, real-world data with de-identified administrative claims and electronic health records (EHR). The cohort included adults (>18 years) with evidence of newly diagnosed PN (ICD9 793.11, 793.19; ICD10 R91.1*, R91.8*) from 1/2014 to 12/2020 in claims (the first claim identified was considered the index date) and ≥1 lung nodule measurement in the EHR with a note date +/- 30 days from the index date. Continuous enrollment in a commercial or Medicare Advantage plan for 12 months pre- and 12 months post-index was required. Exposure categories were created based on lung nodule size; < 6mm, 6-8mm, > 8mm-15mm, > 15-30mm. During the 12-month follow-up, we identified a diagnosis of invasive lung cancer (≥1 claims for ICD9 162.xx; ICD10 C34.xx) or carcinoma in situ of the lung (ICD9 231.xx; ICD10 D02.xx). Rates of repeat imaging, biopsy, and surgery were examined among patients with (LC cohort) and without lung cancer (benign PN cohort) during the 12-month follow-up period. Results: Among 4,304 patients with a nodule measurement, 4.7% (n = 201) were diagnosed with LC during the follow-up period; 2.1%, 4.2%, 8.2%, and 28.3% among those with lung nodules < 6mm, 6-8mm, > 8-15mm, and > 15-30mm, respectively. As expected, the proportion of patients receiving procedures during the follow-up period was significantly higher in patients with LC compared to those with benign PNs (p < 0.01), regardless of lung nodule size (see column percentages in Table). However, the majority (53%) of all procedures were performed in the benign PN cohort. Among all patients that underwent a procedure during the study period, 63% of bronchoscopy, 49% of TTNB, and 38% of thoracic surgery occurred in patients with benign PNs (see row percentages in Table). Conclusions: Although several professional guidelines exist for the management of incidental PN, there continues to be wide variation in the management of PNs with invasive procedures frequently performed in patients ultimately identified to have benign disease. Methods to improve risk stratification of pulmonary nodules would be of significant clinical utility.

*p < 0.01