Table 1.

Distribution of nongenetic variables in cases and controls

Cases (n = 1,227)Controls (n = 1,325)χ2 or t test, unadjusted P-value
Variablena (%)na (%)
Age, y
20–49239 (19.5)151 (11.4)<0.0001
50–54189 (15.4)156 (11.8)
55–59207 (16.9)199 (15.0)
60–64205 (16.7)202 (15.2)
65–69168 (13.7)237 (17.9)
70–74135 (11.0)216 (16.3)
75–8084 (6.8)164 (12.4)
Sex
Male938 (76.4)924 (69.7)0.0001
Female289 (23.6)401 (30.3)
Race
European-American922 (75.1)1,074 (81.1)0.0003
African-American305 (24.9)251 (18.9)
Drinking (lifetime ethanol intake in mL)<0.0001
Never-drinkers117 (9.5)280 (21.1)
>0 to <134,699210 (17.1)467 (35.2)
134,699 to <757,550318 (25.9)360 (27.2)
757,550+505 (41.2)173 (13.1)
Missing77 (6.3)45 (3.4)
Smoking (duration in y)<0.0001
0160 (13.0)497 (37.5)
1–19104 (8.5)266 (20.1)
20–39435 (35.5)314 (23.7)
40–49295 (24.0)131 (9.9)
50+155 (12.6)71 (5.4)
Missing78 (6.4)46 (3.5)
Poverty group (at or above, or below, federal poverty guideline)<0.0001
≥Poverty guideline816 (66.5)1,088 (82.1)
<Poverty guideline356 (29.0)187 (14.1)
Had a routine dental visit in past 10 years?<0.0001
Yes781 (63.7)1,115 (84.2)
No438 (35.7)210 (15.8)
Drank alcoholic beverages in prior 20 years?0.8851
No24 (2.0)27 (2.0)
Yes1,202 (98.0)1,298 (98.0)
Ever exposed to environmental tobacco smoke at work0.0024
No316 (25.8)414 (31.2)
Yes909 (74.1)911 (68.8)
Ever exposed to environmental tobacco smoke at home<0.0001
No399 (32.5)592 (44.7)
Yes827 (67.4)732 (55.2)
Ever used non-cigarette tobacco products0.1165
No754 (61.5)854 (64.5)
Yes473 (38.5)471 (35.5)
Had health insurance at reference date<0.0001
Yes1,068 (87.0)1,250 (94.3)
No154 (12.6)74 (5.6)
Highest education level attained<0.0001
≥High school828 (67.5)1,123 (84.8)
<High school399 (32.5)202 (15.2)
Ever had loose permanent tooth due to disease<0.0001
No765 (62.3)1,018 (76.8)
Yes455 (37.1)305 (23.0)
Ever regularly used mouthwash0.8572
No502 (40.9)549 (41.4)
Yes719 (58.6)775 (58.5)
Family history of SCCHN among first-degree relatives0.3848
No1,206 (98.3)1,296 (97.8)
Yes21 (1.7)29 (2.2)
Mean African ancestry, %23.819.70.0008
  • aFrequencies for all variables may not sum to the total number of cases and controls, due to missing values.