| The primary etiologic agents for head and neck cancer (HNCA), alcohol and tobacco exposure, may also contribute to the high prevalence of comorbid conditions and generally poor survival of persons with HNCA. This thesis assessed the prognostic role of comorbidity in persons with HNCA, and the effect of comorbidity index choice in assessing that role, using both claims- and clinical-record-derived comorbidity data.; Claims comorbidity data were derived from a linkage of Health Care Finance Administration Medicare (HCFA) files to the appropriate files of the Surveillance, Epidemiology, and End Results (SEER) Program to identify persons diagnosed with HNCA from 1985–1993 (N = 9,386). Clinical-record comorbidity data were derived from HNCA patients diagnosed at age 65 years or older, whose treatment included surgery by the Johns Hopkins Otolaryngology service from 1990 to 1997 (N = 388).; Using claims comorbidity data (SEER/HCFA) and adjusting for age and historic stage at diagnosis, race, sex, marital status, socioeconomic status, histologic grade, anatomic site, treatment, and pre-1991 diagnosis, Charlson comorbidity index scores of 0, 1, and 2+ had estimated relative hazards (RH) with (95% confidence intervals) of 1.00, 1.33 (1.21–1.47), and 1.83 (1.64–2.05), respectively, (p-value for trend < 0.0001).; Additional comorbidity indexes compared were the HNCA index; an adaptation of the Charlson index for a HNCA population, the ATC index; a count of conditions associated with alcohol and tobacco use, and the American Society of Anesthesiologists' (ASA) class. Adjusted RH (and 95% confidence intervals) for an index score of 0 compared to a score of 1 or more for each comorbidity index were 1.50 (1.43–1.68) Charlson index, 1.53 (1.42–1.66) HNCA index, and 1.49 (1.32–1.68) ATC index. Using clinically derived comorbidity data, ASA class 3 or 4 compared to 1 or 2 and Charlson index score 1 or more compared to 0 adjusted RH's with (95% confidence intervals) were 2.00 (1.38–2.89) and 1.59 (1.17–2.17), respectively. All indexes, except the ATC index, displayed dose-response patterns.; This thesis establishes comorbidity as a predictor of survival in persons diagnosed with HNCA after 65 years of age. The ASA class, ATC, HNCA and Charlson indexes appear well-suited to the measurement of comorbidity in these HNCA populations. |
