Table 3.
Characteristics, incident lymphoid neoplasm and event rate in the population born in Sub-Saharan Africa (SSA) with and without malaria
| Population born in SSA, all registered periods of stay in Sweden from 1987 | ||||||
|---|---|---|---|---|---|---|
| Periods after malaria diagnosis, n (%) (N = 1426) | Lymphoid neoplasms, n (%) | Event rate, n lymphoid neoplasms/1000 person-years (95% CI) | Periods without previous malaria diagnosis, n (%) (N = 177,721) | Lymphoid neoplasms, n (%) | Event rate, n lymphoid neoplasms/1000 person-years (95% CI) | |
| Total number of individuals | 1305 | 6 | 0.39 (0.17–0.86) | 170451a | 206 | 0.12 (0.10–0.14) |
| Total follow-up time, person-years | 15,497 | 1,720,550 | ||||
| Sex | ||||||
| Male | 976 (68.4) | 4 (66.7) | 0.39 (0.15–1.00) | 94,286 (53.1) | 125 (60.7) | 0.14 (0.12–0.16) |
| Female | 450 (31.6) | 2 (33.3) | 0.39 (0.10–1.55) | 83,435 (47.0) | 81 (39.3) | 0.10 (0.08–0.12) |
| Region of birth | ||||||
| East Africa | 596 (41.8) | 0 | – | 142,237 (80.0) | 145 (70.4) | 0.11 (0.09–0.13) |
| Middle Africa | 166 (11.6) | 2 (33.3) | 1.17 (0.29–4.67) | 8316 (4.7) | 14 (6.8) | 0.17 (0.10–0.30) |
| Western Africa | 658 (46.1) | 4 (66.7) | 0.58 (0.22–1.56) | 22,548 (12.7) | 38 (18.5) | 0.16 (0.12–0.22) |
| Southern Africa | 6 (0.4) | 0 | – | 4620 (2.6) | 9 (4.4) | 0.20 (0.11–0.39) |
| Age at first immigration (y) | ||||||
| < 18 | 385 (27.0) | 0 | – | 65,442 (36.8) | 30 (14.6) | 0.05 (0.03–0.07) |
| 18–29 | 641 (45.0) | 3 (50.0) | 0.43 (0.14–1.33) | 63,178 (35.6) | 72 (35.0) | 0.11 (0.09–0.14) |
| 30–39 | 331 (23.2) | 3 (50.0) | 0.89 (0.29–2.77) | 33,205 (18.7) | 59 (28.6) | 0.20 (0.15–0.25) |
| ≥ 40 | 69 (4.8) | 0 | – | 15,896 (8.9) | 45 (21.8) | 0.37 (0.28–0.50) |
| Age at lymphoma/end of follow-up (y) | ||||||
| 0–29 | 277 (19.4) | 0 | – | 74,370 (41.9) | 33 (16.0) | 0.07 (0.05–0.10) |
| 30–49 | 684 (48.0) | 1 (16.7) | 0.14 (0.02–0.10) | 78,076 (43.9) | 89 (43.2) | 0.11 (0.09–0.13) |
| ≥ 50 | 465 (32.6) | 5 (83.3) | 0.75 (0.31–1.81) | 25,275 (14.2) | 84 (40.8) | 0.18 (0.15–0.23) |
| Follow-up time from immigration (y) | ||||||
| < 5 | 232 (16.3) | 0 | – | 67,420 (37.9) | 74 (35.9) | 0.37 (0.29–0.46) |
| 5–9 | 252 (17.7) | 0 | – | 51,952 (29.2) | 37 (18.0) | 0.10 (0.07–0.13) |
| 10–19 | 431 (30.2) | 2 (33.3) | 0.44 (0.11–1.78) | 32,085 (18.0) | 51 (24.8) | 0.11 (0.09–0.15) |
| 20–30 | 511 (35.8) | 4 (66.7) | 0.45 (0.7–1.21) | 26,264 (14.8) | 44 (21.4) | 0.06 (0.05–0.09) |
| Total years in malaria-endemic country | ||||||
| 0–9 | 165 (11.6) | 0 | – | 31,747 (17.9) | 18 (8.7) | 0.05 (0.03–0.09) |
| 10–19 | 268 (18.8) | 0 | – | 40,642 (22.9) | 16 (7.8) | 0.04 (0.03–0.07) |
| 20–29 | 582 (40.8) | 3 (50.0) | 0.48 (0.15–1.50) | 55,915 (31.5) | 67 (32.5) | 0.11 (0.09–0.14) |
| ≥ 30 | 411 (28.8) | 3 (50.0) | 0.73 (0.24–2.27) | 49,417 (27.8) | 105 (51.0) | 0.24 (0.20–0.30) |
Individuals included from the first immigration or from 1987 if immigration occurred before 1987
CI confidence interval, N total number, n number, SSA Sub-Saharan Africa, y year
aIncludes 28 individuals that later become exposed