Using comorbidity indexes to predict costs for head and neck cancer

To determine whether the general Charlson Comorbidity Index (CCI) and the head and neck cancer-specific Washington University Head and Neck Cancer Comorbidity Index (WUHNCCI) were useful for predicting cost of treatment for elderly patients with head and neck cancer.

Retrospective, observational study.

A total of 1780 Medicare patients with head and neck cancer, who were treated between 1984 and 1994, were analyzed using the Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked database.

Total Medicare payments were accumulated for each patient up to 1 and 5 years. Linear regression was used to estimate the impact of the comorbidity indexes on costs, controlling for demographics, site, stage, and treatment modality.

Neither the WUHNCCI nor the CCI was significantly associated with 1-year costs. However, the effect of the WUHNCCI on 5-year costs was statistically significant (P<.001). A 1-point increase in the WUHNCCI from 4 to 5 was associated with an increase in 5-year costs of $2105. A 1-point increase in the WUHNCCI from 9 to 10 was associated with an increase in 5-year costs of $2837.

These results suggest that comorbidity indexes for head and neck cancer may be useful for prognostication of patient outcomes and predicting costs.