Table 1: Comparison of demographic and lifestyle characteristics between HNC cases and controls.

CharacteristicsControls no.
(%)
Patients no.
(%)
Sample size

Gender0.004
 Male30 (52.6)34 (75.6)
 Female27 (47.4)11 (24.4)
Age (years)NS
 Mean ± SD
 ≤5525 (43.4)16 (35.6)
 >5532 (52.6)29 (64.4)
Tobacco smoking <0.001
 No44 (77.2)18 (40.0)
 Yes13 (22.8)27 (60.0)
 Mean ± SD (PY)a c
Tobacco chewing NS
 No48 (84.2)31 (68.9)
 Yes9 (15.8)14 (31.1)
 Mean ± SD (CY)b c
Alcohol drinking<0.001
 No57 (100.0)31 (68.9)
 Yes0 (0.0)14 (31.1)
Occupational exposure <0.001
 No45 (78.9)16 (35.6)
 Yes12 (21.1)29 (64.4)
 Mean ± SD (year) c
OccupationNS
 Cement worker7 (12.3)15 (33.3)
 Farmer5 (8.8)9 (20.0)
 Painter5 (8.8)5 (11.1)
Amalgam fillings 0.001
 No38 (66.7)27 (60.0)
 Yes19 (33.3)18 (40.0)

Two-sided chi-square test. aPY: smoking index expressed as the number of packs of 20 tobacco cigarettes per day for 1 year.
bCY: consumption year = frequency of neffa consumed−kept/day × duration of year.
c .