Table1.
Characteristics of study groups
| GERD Group (physician-assigned) | Population Group with GERD | Population controls without GERD | |
|---|---|---|---|
| Number (%) | Number (%) | Number or Mean (%) | |
| Number of subjects | 301 | 81 | 175 |
| Age (years) | |||
| 20-39 | 12 (4) | 0 (0) | 9 (5) |
| 40-59 | 110 (37) | 25 (31) | 60 (34) |
| 60-79 | 179 (59) | 56 (69) | 106 (61) |
| Race/Ethnicity | |||
| White | 242 (80) | 68 (84) | 148 (85) |
| Black | 17 (6) | 4 (5) | 9 (5) |
| Hispanic | 20 (7) | 3 (4) | 7 (4) |
| Asian | 11 (4) | 5 (6) | 6 (3) |
| Others | 9 (3) | 0 (0) | 5 (3) |
| Unknown | 2 (1) | 1 (1) | 0 (0) |
| Male | 207 (69) | 58 (72) | 116 (66) |
| Smoking status (Ever smoked) | 175 (58) | 54 (67) | 79 (45) |
The groups were frequency matched by sex, age (by 5 year age groups) and center of diagnosis (see methods section).