Validation of the Washington University Head and Neck Comorbidity Index in a cohort of older patients

Abstract

Objectives: To validate the prognostic ability of the Washington University Head and Neck Comorbidity Index (WUHNCI) relative to 5-year survival in a cohort of older patients with head and neck cancer and to compare it with that of the Adult Comorbidity Evaluation 27 (ACE-27).

Design: Validation study.

Setting: Academic research.

Patients: Three hundred twenty-one patients older than 70 years with head and neck cancer in a tertiary cancer center. Comorbidity was measured using the ACE-27, WUHNCI, and National Cancer Institute (NCI) comorbidity index.

Main outcome measure: Five-year overall survival.

Results: Five-year overall and cancer-specific survival, respectively, were as follows: Using the WUHNCI, 52.2% and 62.9% for a score of 0; 25.1% and 41.7% for a score of 1; 39.3% and 64.9% for a score of 2; and 19.5% and 45.0% for a score of 3 or higher. Using the ACE-27, 54.4% and 61.7% for a score of 0 (no comorbidity); 46.8% and 61.7% for a score of 1 (mild comorbidity); 31.7% and 51.6% for a score of 2 (moderate comorbidity); and 13.8% and 43.7% for a score of 3 (severe comorbidity). The C statistics were 0.641 for the NCI comorbidity index, 0.656 for the ACE-27, and 0.686 for the WUHNCI.

Conclusions: The WUHNCI did not demonstrate good discriminative power compared with the ACE-27 in a cohort of older patients. To be widely used, instruments developed to measure comorbidities must be reliable in any population. We believe that the ACE-27 is still the best index to assess comorbidities and that it should be used in studies evaluating the prognostic effect of comorbidities.