Common Pitfalls of Head and Neck Research Using Cancer Registries

Pitfalls were identified in 2 major areas—design and data analysis. Design pitfalls included unbalanced cohorts, uncontrolled covariates, and flawed oncologic variables. Analytical pitfalls included incorrect application of univariate analyses, inclusion of inaccurate data, and inclusion of stage IVc disease in curative survival analysis. Additional limitations of database studies were identified, including absence of patient-related outcomes, hypothesis-generating vs practice-changing implications, and inability to differentiate between overall survival and disease-specific survival.