Table 1.
Characteristics of patients with oesophageal squamous cell carcinoma (cases) and matched controls* in Golestan, northern Iran, 2003-7. Values are numbers (percentages) of participants unless stated otherwise
| Characteristic | Cases (n=300) | Controls (n=571) | P value† |
|---|---|---|---|
| Mean (SD) age (years) | 64.5 (10.1) | 64.3 (10.4) | 0.81 |
| Men | 150 (50.0) | 278 (48.6) | 0.70 |
| Women | 150 (50.0) | 293 (51.4) | |
| Area of residence: | |||
| Urban | 82 (27.3) | 150 (26.3) | 0.77 |
| Rural | 218 (72.7) | 421 (73.7) | |
| Duration of residence in rural areas (years): | |||
| 0 | 9 (3.0) | 29 (5.1) | 0.36 |
| 1-20 | 26 (8.7) | 51 (8.9) | |
| >20 | 264 (88.3) | 491 (86.0) | |
| Ethnicity: | |||
| Turkmen | 171 (57.0) | 312 (54.6) | 0.64 |
| Non-Turkmen | 129 (43.0) | 259 (45.4) | |
| Education: | |||
| No school | 267 (89.0) | 474 (83.0) | 0.04 |
| Primary school | 25 (8.3) | 64 (11.2) | |
| Middle school or higher | 8 (2.7) | 33 (5.8) | |
| Car ownership: | |||
| No | 252 (84.3) | 461 (75.6) | 0.003 |
| Yes | 47 (15.7) | 139 (24.4) | |
| Alcohol ever use: | |||
| No | 292 (97.7) | 553 (97.4) | 0.86 |
| Yes | 7 (2.3) | 15 (2.6) | |
| Tobacco‡ and opium use: | |||
| Neither | 166 (55.5) | 398 (69.8) | 0.0002 |
| Tobacco | 43 (14.4) | 66 (11.6) | |
| Opium | 30 (10.0) | 34 (6.0) | |
| Both | 60 (20.1) | 72 (12.6) |
As a result of missing data, the number of cases and controls for some variables may be less than 300 and 571, respectively.
*Although cases and controls were individually matched, percentages of either are not necessarily equal in each category for sex or area of residence as some cases had one matched control and others had two.
†χ2 tests for categorical variables (χ2 for trend in variables with more than two categories) and Wilcoxon rank sum test for continuous variables.
‡Any kind of tobacco consumption, including cigarette, pipe, and hookah (water pipe) and chewing nass (a mixture of tobacco, lime, and ash).