Carney Doebbeling C (Indiana University, Regenstrief Institute)
Lung cancer is common and deadly in veterans. To our knowledge, the impact of primary care utilization on cancer survival has not been investigated. Because persons with lung cancer suffer from other pervasive medical comorbidity (e.g., hypertension, COPD), we hypothesized that primary care utilization was a prognostic indicator of prolonged survival due to the comprehensiveness of care received in primary care settings.
We used CPRS data (1997-2005) to identify male veterans with incident lung cancer (n=323) at a Midwestern VAMC who were established primary care users. Primary care utilization was assessed in the 6-month period following cancer diagnosis. Subjects were followed from cancer diagnosis to death or last date of healthcare utilization. Cox proportional hazards models tested whether primary care utilization was associated with improved survival, adjusting for age, race, marital status, service-connected disability, comorbidity, cancer stage, smoking status, and baseline primary care utilization.
During the first 6 months following lung cancer diagnosis, 81 (25%), 92 (28%), 71 (22%), and 79 (24%) subjects utilized primary care 0, 1, 2, or 3+ times, respectively. Primary care utilization post-cancer diagnosis was not associated with pre-cancer utilization or other determinants of cancer survival, including cancer stage (local vs. metastatic), age, and smoking status. In multivariate analysis, risk of death was 36% (HR=0.64; CI95: 0.45-0.90), 56% (HR=0.44; CI95: 0.29-0.65), and 57% (HR=0.43; CI95: 0.29-0.64) lower for subjects having 1, 2, or 3+ primary care visits, respectively, in the first 6 months following lung cancer diagnosis as compared to those without primary care utilization. The median survival duration (p < 0.0001, log-rank test) was 3.68 months, 7.52 months, 13.88 months, and 13.75 months for subjects with 0, 1, 2, or 3+ primary care visits within 6 months of diagnosis.
Primary care utilization during early cancer treatment is associated with a reduced mortality risk in veterans with newly diagnosed lung cancer. The median survival duration was 3-10 months longer if primary care was utilized within 6 months of cancer diagnosis.
Lung cancer is a leading cause of death and affects many VHA enrollees. Multidisciplinary and integrated healthcare, particularly with primary care, may result in prolonged lung cancer survival. Additional research is needed to investigate how primary care utilization may contribute to prolonged lung cancer survival.