Demographic factors of the pooled study participants
| Demographic factor . | NHL cases, no. (%) . | Controls, no. (%) . |
|---|---|---|
| Pooled total | 12 982 | 16 441 |
| Sex | ||
| Men | 7029 (54.1) | 8895 (54.1) |
| Women | 5953 (45.9) | 7546 (45.9) |
| Age, y | ||
| <20 | 25 (0.2) | 69 (0.4) |
| 20-29* | 357 (2.7) | 946 (5.8) |
| 30-39* | 898 (6.9) | 1699 (10.3) |
| 40-49 | 1740 (13.4) | 2415 (14.7) |
| 50-59 | 3362 (25.9) | 3725 (22.7) |
| 60-69 | 4144 (31.9) | 4670 (28.4) |
| 70-79 | 2328 (17.9) | 2765 (16.8) |
| 80+ | 126 (1.0) | 152 (0.9) |
| Median (range) | 60 (17-89) | 58 (16-96) |
| Education/SES† | ||
| Low | 5038 (38.8) | 5823 (35.4) |
| Medium | 4483 (34.5) | 5974 (36.3) |
| High | 3382 (26.1) | 4562 (27.7) |
| Not recorded | 78 (0.6) | 82 (0.5) |
| Race/ethnicity‡ | ||
| White | 5172 (39.8) | 6507 (39.6) |
| Black | 201 (1.5) | 324 (2) |
| Other/unknown | 528 (4.1) | 556 (3.4) |
| Missing§ | 7081 (54.5) | 9054 (55.1) |
| Demographic factor . | NHL cases, no. (%) . | Controls, no. (%) . |
|---|---|---|
| Pooled total | 12 982 | 16 441 |
| Sex | ||
| Men | 7029 (54.1) | 8895 (54.1) |
| Women | 5953 (45.9) | 7546 (45.9) |
| Age, y | ||
| <20 | 25 (0.2) | 69 (0.4) |
| 20-29* | 357 (2.7) | 946 (5.8) |
| 30-39* | 898 (6.9) | 1699 (10.3) |
| 40-49 | 1740 (13.4) | 2415 (14.7) |
| 50-59 | 3362 (25.9) | 3725 (22.7) |
| 60-69 | 4144 (31.9) | 4670 (28.4) |
| 70-79 | 2328 (17.9) | 2765 (16.8) |
| 80+ | 126 (1.0) | 152 (0.9) |
| Median (range) | 60 (17-89) | 58 (16-96) |
| Education/SES† | ||
| Low | 5038 (38.8) | 5823 (35.4) |
| Medium | 4483 (34.5) | 5974 (36.3) |
| High | 3382 (26.1) | 4562 (27.7) |
| Not recorded | 78 (0.6) | 82 (0.5) |
| Race/ethnicity‡ | ||
| White | 5172 (39.8) | 6507 (39.6) |
| Black | 201 (1.5) | 324 (2) |
| Other/unknown | 528 (4.1) | 556 (3.4) |
| Missing§ | 7081 (54.5) | 9054 (55.1) |
The inclusion of Hodgkin lymphoma cases in several studies led to an imbalance in the age distribution of controls compared with the NHL cases only.
Education/socioeconomic status (SES) groups in each study were based on the tertile distribution of years of education (10 studies) or SES levels obtained from census data (2 studies) in controls.
Participants with Hispanic origin were mainly categorized as “white” (n = 307), but a few individuals were also categorized as “black” (n = 4) or with “other/unknown” ethnicity (n = 24), based on the original categorization in the participating studies.
Ethnicity was generally not recorded in the European studies because of the large predominance of individuals with white origin.