Costs of Diagnostic Assessment for Lung Cancer: A Medicare Claims Analysis

To assess the diagnostic costs leading up to a lung cancer diagnosis in patients with abnormal computed tomography (CT) scans.

A retrospective cohort study using the 5% Medicare claims data (January 1, 2009, to December 31, 2011) was conducted. Patients aged 65 to 74 years with an abnormal chest CT scan were identified. Index was defined as the date of the abnormal chest CT scan. Outcomes assessed over a 12-month follow-up after index included lung cancer diagnosis rate and the use and associated costs of follow-up diagnostic tests up to diagnosis of lung cancer.

Of 8979 patients identified with an abnormal chest CT scan (mean age, 69.3 ± 2.9 years), 13.9% were diagnosed with lung cancer over 12 months. Chest x-rays were the most common diagnostic test. Of the 19% who underwent a biopsy, 43.6% were not diagnosed with lung cancer during follow-up. The average total diagnostic assessment cost per patient was higher for those with versus without lung cancer ($7567 vs. $3558). Among patients not diagnosed with lung cancer, the median diagnostic cost per patient for those with versus without biopsy was ∼ 28 times higher. Adverse events significantly increased the average cost per biopsy (approximately 4-fold).

Total lung cancer diagnostic cost was $38.3M in the defined study sample, of which 43.1% was accounted for by biopsied patients without a lung cancer diagnosis. Additional risk stratification is required to decrease unnecessary biopsy referrals and costs. Further, adverse events significantly increased costs.