How Accurate Are NCDB Comorbidity Assessments in Breast Cancer and Other Resected Tumors?
Posted: Monday, December 17, 2018
A study by Melisa L. Wong, MD, MAS, of the University of California, San Francisco, and colleagues found that the National Cancer Database (NCDB) systematically underestimated comorbidities in patients with surgically resected breast, lung, and colorectal cancers. Although their analysis suggested that this underestimation did not drastically affect prognostic models for postoperative 5-year overall survival, the authors concluded that care should be taken when using NCDB comorbidity data in comparative effectiveness studies. Their findings were published in the Journal of Oncology Practice.
“The NCDB does not differentiate between no documented comorbidities and missing or unavailable comorbidity information. The lack of a missing value category…limits the ability of researchers to identify and analyze these patients differently from patients who truly have no comorbidities,” wrote the authors.
In this NCDB Special Study, de-identified medical records of 11,243 women with stage II to III breast cancer who were treated with definitive surgical resection in 2006 and 2007 were reabstracted by cancer registrars. A total of 10 eligible patients (with no postoperative disease and adequate follow-up) were included from each American College of Surgeons Commission on Cancer–accredited facility. Data were collated from 1,214 facilities and compared with the Charlson-Deyo Comorbidity Index (CCI) scores reported in the NCDB.
In total, comorbidities were underestimated in 19.1% of patients with breast cancer and overestimated in 3.8%. Relative to lung and colorectal cancers, comorbidity was lowest (2.8% NCDB CCI 2+) and postoperative 5-year survival was highest in patients with breast cancer (85.8% for stage II and 69.6% for stage III).