OBJECTIVES: Although epidemiology of lung cancer is well known, epidemiology of PNs remains understudied. This retrospective claims analysis aimed to examine incidence of PNs in 2020 in the US.

METHODS: MarketScan® Commercial and Medicare Databases were retrospectively queried to identify patients from 1/1/2020-12/31/2020 who had an International Classification of Diseases (ICD) diagnosis code for solitary PN (ICD-10: R91.1) or multiple PN (ICD-10: R91.8). Patients were required to have continuous enrollment from 1/1/2020-12/31/2020 and during a 2-year exclusionary period (1/1/2018-12/31/2019) to estimate PN incidence. To account for other diagnoses included in ICD-10 R91.8, patients were excluded if they had a diagnosis of pneumonia, pneumothorax, respiratory failure, sepsis, atelectasis, histoplasmosis, coccidioidomycosis, or other respiratory signs and symptoms same day as R91.8. Raw incidence rates in the MarketScan Databases were projected to the U.S. population with Commercial and Medicare insurance.

RESULTS: A total of 10,522,421 and 10,435,005 patients had continuous enrollment in medical and pharmacy benefits and no earlier diagnosis of PN (based on R91.1 and R91.1/R91.8 without exclusions in 2018 or 2019). Of these patients, 39,497 had a R91.1 diagnosis while 78,620 had a R91.1/R91.8 (without exclusions) diagnosis, equating to 0.375% and 0.753% raw incidence rates, respectively. Within the R91.1 only group, projected PN incidence rates in 2020 were 0.218% for the Commercial population, and 1.51% for the Medicare population. Within the R91.1/R91.8 group, projected PN incidence rates in 2020 were 0.463% for the Commercial population, and 3.08% for the Medicare population.

CONCLUSIONS: While the incidence of PNs in the US likely lies between 0.218-0.463% for the Commercial population and 1.51-3.08% for the Medicare population limitations exist with the ICD codes used for PNs. Future studies may be beneficial to identify more specific incidence information and inform national projections.