OBJECTIVES: While most PNs are benign, a percentage may develop into lung cancer. Much is known about lung cancer epidemiology, but recent studies have not been published that evaluate the prevalence of PNs. This study aimed to examine the prevalence of PNs in 2019 in the US.

METHODS: MarketScan® Commercial and Medicare Databases were queried to identify patients from 1/1/2019-12/31/2019 with an International Classification of Diseases (ICD) code for solitary PN (ICD-10: R91.1) or multiple PNs (ICD-10: R91.8). To adjust for other diagnoses included in ICD-10 R91.8, patients were excluded if they had other lung diagnoses (e.g., pneumonia) on the same day. Raw prevalence rates in the MarketScan Databases were projected to the U.S. population with Commercial and Medicare insurance.

RESULTS: 17,711,286 patients had continuous enrollment in medical and pharmacy benefits in the Databases from 1/1/2019 to 12/31/2019. Among these patients, 98,265 (0.555% raw prevalence) had ≥1 inpatient or outpatient claim with a diagnosis of R91.1, and 193,506 (1.093% raw prevalence) had a diagnosis of R91.1/R91.8 without exclusions. In both groups, the majority of PN patients were between age 45-64 years or age 65+. The median age at PN diagnosis in both groups was 59, whereas the mean ages were 58.7 (R91.1 only) and 57.4 years (R91.1/R91.8). Projected prevalence estimates were 0.342% and 0.702% in the Commercial population and 3.06% and 5.97% in the Medicare population for the R91.1 and R91.1/R91.8 groups, respectively.

CONCLUSIONS: PNs are typically identified with ICD codes for “solitary pulmonary nodule” (R91.1) for single nodule or “other nonspecific abnormal finding of lung field” (R91.8) for multiple nodules, but this latter code may include other diagnoses. Given this, it is difficult to estimate the true prevalence of PNs in the US. The true prevalence lies between 0.342-0.702% for the Commercial population and 3.06-5.97% for the Medicare population.