Predictors of guideline treatment nonadherence and the impact on survival in patients with colorectal cancer.

Abstract

254 Background: We investigated the effect of comorbidity, age, health insurance payer status, and race on the risk of nonadherence with National Comprehensive Cancer Network (NCCN) treatment guidelines for colorectal cancer (CRC) patients. In addition, the prognostic impact of NCCN treatment nonadherence on survival was assessed. Methods: Colon and rectal cancer patients who received primary treatment at Memorial University Medical Center in Savannah, GA from 2003 to 2010 were eligible for this study (final N = 679). Modified Poisson regression was used to obtain risk ratios for the outcome of nonadherence with NCCN treatment guidelines. Hazard ratios (HRs) for the relative risk of CRC-related death were obtained by Cox regression. Results: Guideline-adherent treatment was received by 82.5% of patients. Moderate/severe comorbidity, being uninsured, having rectal cancer, older age, and increasing tumor stage were associated with increased risks of receiving nonadherent treatment. Treatment nonadherence was associated with 4.5 times the risk of CRC-related death (HR, 4.53; 95% CI, 2.56-8.00) in the first year following diagnosis and 2.0 times the risk of death (HR, 1.97; 95% CI, 1.20-3.25) in years 2 to 5. The detrimental effect of nonadherence was demonstrated across all levels of comorbidity and age. Conclusions: Although there are medically justifiable reasons to deviate from NCCN treatment guidelines in CRC patients, patients who received nonadherent treatment had much higher risks of CRC-related death, especially in the first year following diagnosis. This study’s results highlight the importance of cancer health services research to drive quality improvement efforts in cancer care for CRC patients. [Table: see text]