OBJECTIVES: This cross-sectional research objective of a claims analysis aimed to examine incidence of PNs in 2019.

METHODS: MarketScan® Commercial and Medicare Databases were retrospectively queried to identify patients from 1/1/2019-12/31/2019 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 1/1/2019-12/31/2019 and during a 2-year exclusionary period (1/1/2017-12/31/2018) 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 on the 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: In total, 11,127,202 and 11,040,157 patients had continuous enrollment and no earlier diagnosis of PN (based on R91.1 and R91.1/R91.8 without exclusions in 2017 or 2018). Of these, 45,095 patients had a R91.1 diagnosis (0.405% raw incidence) and 87,358 patients had a R91.1/R91.8 diagnosis without exclusions (0.791% incidence) in 2019. Although statistical analyses were not performed, incidence rates were similar between genders amongst both study groups. Projected prevalence estimates were 0.242% and 0.496% in the Commercial population and 1.94% and 3.93% in the Medicare population for the R91.1 and R91.1/R91.8 groups, respectively.

CONCLUSIONS: While the incidence of PNs in the US likely lies between 0.242-0.496% for the Commercial population and 1.94-3.93% for the Medicare population, limitations exist with the ICD codes used for PNs. Future real-world studies may be beneficial in order to identify more specific incidence information and to further inform other characteristics such as age, comorbidities, and gender.