Characteristics of the studies on selenium and lung cancer included in the pooled analysis of mean differences
| Author | Study design | Assessment method | Gender | Location | Years of follow-up | No. of cases/controls | Mean (SD) selenium* | Mean difference† | P‡ | ||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Controls | Cases | ||||||||||
| Goodman et al. (19) | NCC | Serum | All | Multicenter, United States | 5–14 | 356/356 | 117.7 (18.5) | 119.1 (19.6) | −1.4 | 0.33 | |
| Knekt et al. (26) | NCC | Serum | Male | Finland | 8–12 | 189/378 | 61.0 (13.5) | 57.0 (16.7) | 4.0 | <0.01 | |
| Knekt et al. (26) | NCC | Serum | Female | Finland | 8–12 | 9/18 | 63.4 (13.8) | 62.8 (17.9) | 0.6 | >0.05 | |
| Knekt et al. (13) | NCC | Serum | All | Finland | 16–19 | 91/177 | 57.8 (16.9) | 53.2 (24.3) | 4.6 | 0.14 | |
| Menkes et al. (14) | NCC | Serum | All | Maryland | 9 | 99/196 | 110 (16.0) | 113 (18.0) | −3 | 0.16 | |
| Nomura et al. (15) | NCC | Serum | Male | Hawaii | 11 | 71/293 | 124.9 (19.4) | 125.4 (22.1) | −0.5 | >0.50 | |
| Salonen et al. (16) | NCC | Serum | All | Finland | 6 | 23/23 | 52.4 (11.5) | 49.0 (9.6) | 3.4 | 0.28 | |
| Virtamo et al. (38) | Cohort | Serum | Male | Finland | 9 | 38/964 | 55.3 (15.5) | 51.5 (16.0) | 3.8 | 0.16 | |
| Garland et al. (39) | NCC | Toenail | Female | Multicenter, United States | 3.5 | 47/47 | 0.90 (0.31) | 0.81 (0.17) | 0.09 | 0.03 | |
| Hartman et al. (40) | NCC | Toenail | Male | Finland | 5–8 | 250/250 | 0.55 (0.13) | 0.54 (0.13) | 0.01 | >0.05 | |
| van den Brandt et al. (18) | Cohort | Toenail | Male | Netherlands | 3.3 | 335/1211 | 0.55 (0.13) | 0.53 (0.21) | 0.02 | 0.13 | |
| van den Brandt et al. (18) | Cohort | Toenail | Female | Netherlands | 3.3 | 35/1248 | 0.58 (0.11) | 0.54 (0.08) | 0.04 | 0.01 | |
| Zhou et al. (25) | Case-control | Diet/FFQ | Female | China | – | 290/290 | 39.80 (33.00) | 36.10 (16.00) | 3.70 | 0.08 | |