Table 2.

Characteristics of the studies on selenium and lung cancer included in the pooled analysis of mean differences

AuthorStudy designAssessment methodGenderLocationYears of follow-upNo. of cases/controlsMean (SD) selenium*
Mean differenceP
ControlsCases
Goodman et al. (19)NCCSerumAllMulticenter, United States5–14356/356117.7 (18.5)119.1 (19.6)−1.40.33
Knekt et al. (26)NCCSerumMaleFinland8–12189/37861.0 (13.5)57.0 (16.7)4.0<0.01
Knekt et al. (26)NCCSerumFemaleFinland8–129/1863.4 (13.8)62.8 (17.9)0.6>0.05
Knekt et al. (13)NCCSerumAllFinland16–1991/17757.8 (16.9)53.2 (24.3)4.60.14
Menkes et al. (14)NCCSerumAllMaryland999/196110 (16.0)113 (18.0)−30.16
Nomura et al. (15)NCCSerumMaleHawaii1171/293124.9 (19.4)125.4 (22.1)−0.5>0.50
Salonen et al. (16)NCCSerumAllFinland623/2352.4 (11.5)49.0 (9.6)3.40.28
Virtamo et al. (38)CohortSerumMaleFinland938/96455.3 (15.5)51.5 (16.0)3.80.16
Garland et al. (39)NCCToenailFemaleMulticenter, United States3.547/470.90 (0.31)0.81 (0.17)0.090.03
Hartman et al. (40)NCCToenailMaleFinland5–8250/2500.55 (0.13)0.54 (0.13)0.01>0.05
van den Brandt et al. (18)CohortToenailMaleNetherlands3.3335/12110.55 (0.13)0.53 (0.21)0.020.13
van den Brandt et al. (18)CohortToenailFemaleNetherlands3.335/12480.58 (0.11)0.54 (0.08)0.040.01
Zhou et al. (25)
Case-controlDiet/FFQFemaleChina290/29039.80 (33.00)36.10 (16.00)3.700.08