Purpose: To explore demographic and regional factors associated with the use of positron emission tomography (PET) in patients with non-small cell lung cancer (NSCLC) and to determine whether their associations with PET use has changed over time.
Materials and methods: The Office of Human Research Ethics at the University of North Carolina and the institutional review board of the Duke University Health System approved (with waiver of informed consent) this retrospective analysis of Surveillance Epidemiology and End Results Medicare data for Medicare beneficiaries given a diagnosis of NSCLC between 1998 and 2007. The primary outcome was change in the number of PET examinations 2 months before to 4 months after diagnosis, examined according to year and sociodemographic subgroup. PET use was compared between demographic and geographic subgroups and between early (1998-2000) and late (2005-2007) cohorts by using χ(2) tests. Factors associated with use of PET during the study period were further examined by using logit and linear probability multivariable regression analyses.
Results: The final cohort included 46 544 patients with 46 935 cases of NSCLC. By 2005, more than half of patients underwent one or more PET examinations, regardless of demographic subgroup. In multivariable logistic regression analysis, patients who underwent PET were more likely to be married, nonblack, and younger than 80 years and to live in census tracts with higher education levels or in the Northeast (P < .001 for all). Living within 40 miles of a PET facility was initially associated with undergoing PET (P < .001), but this association disappeared by 2007. Imaging rates increased more rapidly in patients who were nonblack (P ≤ .01), patients who were younger than 81 years (P < .001), and patients who lived in the Northeast and South (P < .001).
Conclusion: PET imaging among Medicare beneficiaries with NSCLC was initially concentrated among nonblack patients younger than 81 years. Despite widespread adoption among all subgroups, differences within demographic subgroups remained.