Association of Primary Care Physician Density With Metastatic Cancer at Initial Diagnosis: A Population-Based Study of 7 Cancers

Background

Patients with metastatic cancer at initial diagnosis have the worst prognosis. Despite their involvement in initial assessment, the relationship between Primary Care Physician availability and metastatic cancer at initial diagnosis remains unexplored. Our objective was to determine whether Primary Care Physician availability is associated with patients having metastatic cancer at initial diagnosis. Methodology: This was a cross-sectional study of patients aged ≥ 18 and diagnosed with breast, colorectal, liver, lung, ovarian, pancreatic, or prostate cancer from 2015 to 2019. Population-based Texas and California cancer registries were used for patient data. The main exposure was county-level Primary Care Physician density per 3500 individuals. Additional exposures included demographic factors, insurance, rural-urban continuum codes, county poverty rates, and US State at Diagnosis. The primary outcome was adjusted odds of metastatic cancer at initial diagnosis. Subgroup analyses based on insurance type, age group, and metropolitan residence were performed. Models were stratified by cancer type.