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 prevalence of PNs in 2020.

METHODS: MarketScan® Commercial and Medicare Databases were retrospectively queried to identify patients from January 1, 2020-December 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). In order to adjust for other diagnoses included in ICD-10 R91.8, a list of lung-related ICD codes (e.g., pneumonia) was developed to exclude patients if diagnosed same day. Raw prevalence rates in the MarketScan Databases were projected to the U.S. population with Commercial and Medicare insurance.

RESULTS: 17,608,237 patients had continuous benefit enrollment between 1/1/2020 and 12/31/2020 and were eligible to be included. Of these, there were 98,793 patients with at least 1 inpatient or outpatient claim for R91.1 (0.561% raw prevalence) and 200,086 patients for R91.1/R91.8 without exclusions (1.136% raw prevalence). Within both groups, the prevalence of PNs increased with age (0.012% and 0.097% for <18 years to 2.58% and 5.89% for 80+ years for the R91.1 and R91.1/R91.8 groups, respectively). Projected prevalence estimates were 0.311% and 0.661% in the Commercial population and 2.70% and 5.37% in the Medicare population for the R91.1 and R91.1/R91.8 groups, respectively.

CONCLUSIONS: PNs are typically identified with the ICD codes for “solitary pulmonary nodule” (R91.1) for single nodule or “other nonspecific abnormal finding of lung field” 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 0.311-0.661% for the Commercial population and 2.70-5.37% for the Medicare population.