Table 1.
Distribution of cases and controls stratified by sex among selected risk factors in a case-control study of esophageal squamous cell carcinoma in Iran1
| Variable | Male | Female | P-value2 | ||
|---|---|---|---|---|---|
| Cases | Control | Cases | Control | ||
| Participants, n | 18 (32.1) | 38 (67.9) | 29(33.3) | 58(66.7) | |
| Age3, year | 60.0(54.75-67.00) | 60.0 (54.25-67.00) | 57.0(50.00-70.50) | 58.0 (48.75-72.25) | 0.17 |
| ≤58 | 8(44.4) | 17(44.7) | 17(58.6) | 32(55.2) | |
| >58 | 10(55.6) | 21(55.3) | 12(41.4) | 26(44.8) | |
| Education, year | |||||
| Illiterate | 14(77.8) | 25(65.8) | 28(96.6) | 55(94.8) | <0.001 |
| Literate | 4(22.2) | 13(34.2) | 1(3.4) | 3(5.2) | |
| Monthly family income, US $ | |||||
| <300 | 15 (83.3) | 33 (86.8) | 28 (96.6) | 53 (91.4) | 0.14 |
| ≥300 | 3 (16.7) | 5(13.2) | 1 (3.4) | 5 (8.6) | |
| Place of residence | |||||
| Rural | 11(61.1) | 20(52.6) | 22(75.9) | 28(48.3)* | 0.80 |
| Urban | 7(38.9) | 18(47.4) | 7(24.1) | 30(51.7)* | |
| Smoking history | |||||
| Never smoker | 5(27.8) | 17(44.7) | 23(79.3) | 51(87.9) | <0.001 |
| Ex-smoker, pack year < 10 | 3(16.7) | 3(7.9) | 3(10.3) | 4(6.9) | |
| Ex-smoker, pack year≥10 | 1(5.5) | 11(28.9) | 3(10.3) | 1(1.7) | |
| Current smoker, pack year < 20 | 3(16.7) | 4(10.5) | 0(0.0) | 1(1.7) | |
| Current smoker, pack year ≥20 | 6(33.3) | 3(7.9) | 0(0.0) | 1(1.7) | |
| Having symptoms of GERD4 | 6(33.3) | 6(15.8) | 10(34.5) | 3(5.2)* | 0.31 |
| Familial cancer history | 1(5.6) | 0(0.0) | 3(10.3) | 0(0.0)* | 0.48 |
| Physical activity | |||||
| Light | 13(72.2) | 21(55.3)* | 16(75.9) | 35(60.4)* | 0.001 |
| Heavy | 5(27.8) | 17(44.7)* | 7(24.1) | 23(39.6)* | |
| BMI, kg/m2 | 19.9(3.1)5 | 24.8(4.0)* | 20.8(3.3) | 25.7(4.3)* | 0.01 |
| ≤24.9 | 16(88.9) | 20(52.6)* | 24(82.8) | 27(46.6) | |
| >24.9 | 2(11.1) | 18(47.4)* | 5(17.2) | 31(53.4) | |
| NSAIDs use | |||||
| Aspirin | 2(11.2) | 0(0.0) | 1(5.6) | 0(0.0) | 0.63 |
| Non-aspirin | 3(7.9) | 0(0.0) | 1(3.4) | 0(0.0) | |
| Food and beverage temperature | |||||
| Hot | 15(83.3) | 6(15.8)* | 17(58.6) | 9(15.5)* | 0.03 |
| Warm/cold | 3(16.7) | 32(84.2)* | 12(41.4) | 49(84.5)* | |
| Cooking method | |||||
| Fried/barbecued | 8(44.4) | 3(7.9)* | 6(20.7) | 3(5.2)* | 0.14 |
| Boiled | 7(38.9) | 21(55.3)* | 10(34.5) | 49(84.5)* | |
| Both | 3(16.7) | 14(36.8)* | 13(44.8) | 6(10.3)* | |
GERD: Gastro-esophageal reflux disease; BMI: Body mass index; NSAIDs: Non-steroidal anti-inflammatory drugs
*Statistically significant between case and control groups (p < 0.05)
1Values are n (%), unless otherwise noted
2P-values were estimated using chi-square statistics, Fishers' exact test or independent t-test for the difference between genders
3Median (interquartile range (IQR))
4Patients who present with the typical GERD symptoms of heartburn and acid regurgitation
5Mean (SD)