Development of population‐level colon cancer pathway concordance measures and association with survival

Clinical cancer pathways help standardize healthcare delivery to optimize patient outcomes and health system costs. However, population‐level measurement of concordance between standardized pathways and actual care received is lacking. Two measures of pathway concordance were developed for a simplified colon cancer pathway map for Stage II‐III colon cancer patients in Ontario, Canada: a cumulative count of concordant events (CCCE) and the Levenshtein algorithm. Associations of concordance with patient survival were estimated using Cox proportional hazards models adjusted for patient characteristics and time‐dependent cancer‐related activities. Models were compared and the impact of including concordance scores was quantified using the likelihood ratio chi‐squared test. The ability of the measures to discriminate between survivors and decedents was compared using the C‐index. Normalized concordance scores were significantly associated with patient survival in models for cancer stage—a 10% increase in concordance for Stage II patients resulted in a CCCE score adjusted hazard ratio (aHR) of death of 0.93, 95% CI 0.88‐0.98 and a Levenshtein score aHR of 0.64, 95% CI 0.60‐0.67. A similar relationship was found for Stage III patients—a 10% increase in concordance resulted in a CCCE aHR of 0.85, 95% CI 0.81‐0.88 and a Levenshtein aHR of 0.78, 95% CI, 0.74‐0.81. Pathway concordance can be used as a tool for health systems to monitor deviations from established clinical pathways. The Levenshtein score better characterized differences between actual care and clinical pathways in a population, was more strongly associated with survival and demonstrated better patient discrimination.