Questionnaire and Exposure Assessment
Demographic, lifestyle, oral health, diet, and other common risk factor
information were collected using a structured questionnaire during an
in-home visit conducted by trained nurse-interviewers. Specific
covariates obtained from the questionnaire included age, sex, race;
pack-years of cigarette smoking; ever-consumption of alcohol products;
whether the subject was covered by health insurance on diagnosis date,
what type of insurance the subject was covered by; household income, and
highest attained education level. Race was self-reported from a list of
the following options: white, black, American Indian, Alaskan Native,
Asian/Pacific Islander, other, and don’t know. Given the low overall
number of non-white or black patients (n=28), we focused our analysis on
patients who self-identified as white or black. Clinical information
such as TNM stage and primary treatment were abstracted from the
subjects’ medical record and reviewed by a pathologist and head neck
cancer surgeon. Tumor HPV-status was assessed using p16
immunohistochemistry, and the full protocol has been previously reported
in detail.(15)