Can physician adherence to treatment guidelines improve patient survival? A population-based analysis of non-small cell lung cancer (NSCLC) in Taiwan

Objectives: To explore the relationship between adherence to treatment guidelines and oneyear survival of all stages of non-small cell lung cancer (NSCLC) patients after adjustment for the characteristics of patients, hospitals and physicians. Methods: Population-based data were retrieved from the Taiwan Cancer Data Base (TCDB) in 2004, National Health Insurance Research Database (NHIRD) in 2002-2004 and Taiwan's Death Registries in 2004-2005. This was a retrospective cohort study and Kaplan-Meier analysis was used to construct survival curves. A multivariate Cox proportional hazard model was employed to estimate the hazard ratio (HR). Results: Fifty-seven percent of NSCLC patients were at cancer stage IV. Overall, 66.6% of NSCLC patients in the study cohort were compliant with treatment guidelines. The patients who received treatments in adherence to guidelines had a higher one-year survival rate than those who did not adhere (51.1% vs. 22.1%), even in various stages of cancer. Multivariate analysis showed that the patients who received treatments in adherence to guidelines had a lower risk of one-year mortality (HR=0.44; 95% CI=0.41-0.48). A significant interaction effect between cancer stage and guideline adherence was found. The early-stage cancer patients who adhered to guidelines had a lower risk of one-year mortality then those diagnosed with late-stage cancer. Conclusions: Physician adherence to treatment guidelines is associated with one-year survival of NSCLC patients regardless of the stage of the cancer. Such a favorable effect is particularly noteworthy for patients diagnosed at an early-stage. Early diagnosis and promotion of the adoption of guidelines for treatment are effective strategies for NSCLC control.