title: Comparison of Comorbid Medical Conditions in the National Cancer Database and the SEER-Medicare Database.
abstract: Physicians routinely factor comorbidities into diagnostic and treatment decisions. Analyses of treatment patterns and outcomes using the National Cancer Data Base (NCDB) usually adjust for comorbidities; however, the completeness of comorbidity ascertainment in the NCDB has never been assessed. We compared the prevalence of comorbidities captured in the NCDB and Surveillance, Epidemiology, and End Results (SEER)-Medicare among female breast, non-small-cell lung, and colorectal cancer patients aged ≥66.
  
  
  
  In the NCDB, ten fields were searched for comorbidities. In the SEER-Medicare dataset, Medicare claims were used to identify comorbidities for two time periods: 12 months prior to diagnosis (Prior) and Index claim alone. Chi-square tests were used to compare comorbidity prevalence using propensity score-matched subsamples from each dataset. Kaplan-Meier survival analyses by Charlson-Deyo comorbidity score and data source were conducted.
  
  
  
  Comorbidity prevalence in NCDB did not differ significantly from that identified in SEER-Medicare Index claims across all three cancer sites, except for congestive heart failure, chronic pulmonary disease, and renal disease. However, when compared to the prevalence identified through SEER-Medicare Prior claims, comorbidity prevalence in the NCDB was lower. Overall survival rates by NCDB comorbidity scores were nearly identical to those based on SEER-Medicare Index claims but were lower than those based on SEER-Medicare Prior claims, particularly in higher comorbidity score categories.
  
  
  
  The study found overall similarity of comorbidity prevalence between NCDB and SEER-Medicare Index claims, but much less similarity between NCDB and SEER-Medicare Prior claims. Future researchers should understand the limitation of comorbidities ascertained in the NCDB and interpret results accordingly.
authors.affiliation: American Cancer Society, Atlanta, GA, USA. anna.lin@cancer.org.
authors.forename: Chun Chieh
authors.initials: CC
authors.lastname: Lin
authors.affiliation: Emory University, Atlanta, GA, USA.
authors.forename: Katherine S
authors.initials: KS
authors.lastname: Virgo
authors.affiliation: American Cancer Society, Atlanta, GA, USA.
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Robbins
authors.affiliation: American Cancer Society, Atlanta, GA, USA.
authors.forename: Ahmedin
authors.initials: A
authors.lastname: Jemal
authors.affiliation: American Cancer Society, Atlanta, GA, USA.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Ward
mesh_terms: D000067575:Administrative Claims, Healthcare; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000453:epidemiology; D002289:Carcinoma, Non-Small-Cell Lung / Q000453:epidemiology; D002908:Chronic Disease; D015179:Colorectal Neoplasms / Q000453:epidemiology; D015897:Comorbidity; D016208:Databases, Factual / Q000592:standards* / Q000706:statistics & numerical data; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005260:Female; D006333:Heart Failure / Q000453:epidemiology*; D006801:Humans; D053208:Kaplan-Meier Estimate; D007674:Kidney Diseases / Q000453:epidemiology*; D008171:Lung Diseases / Q000453:epidemiology*; D008175:Lung Neoplasms / Q000453:epidemiology; D008297:Male; D006278:Medicare / Q000592:standards* / Q000706:statistics & numerical data; D009369:Neoplasms / Q000453:epidemiology*; D015995:Prevalence; D018426:SEER Program / Q000592:standards* / Q000706:statistics & numerical data; D015996:Survival Rate; D014481:United States