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Figure 2 | Environmental Health

Figure 2

From: Low dose radiation and cancer in A-bomb survivors: latency and non-linear dose-response in the 1950–90 mortality cohort

Figure 2

Stomach cancer mortality in 0 – 20 mSv subcohort, LRT vs latency. LRT is the likelihood ratio test for comparison of the indicated pair of models evaluated at fixed latency φ, and is χ2 distributed on 1 d.f. (red line shows LRT2p-lin for comparing the two-phase and linear models, green line shows LRTtrans-lin for comparing transient and linear models, blue line shows LRTlin-con for comparing linear and control models) LRT values above 3.84 are significant at p = 0.05, above 6.63 at p = 0.01, above 10.83 at p = 0.001. Other LRT can be derived at each φ value, e.g. LRT2p-con = LRT2p-lin + LRTlin-con and LRTtrans-con = LRTtrans-lin + LRTlin-con while LRT2p-trans = LRT2p-lin - LRTtrans-lin. Latency φ (in years) is used in defining the lagged dose Dφ = DS86 weighted adjusted colon dose if Time-Since-Exposure ≥ φ, Dφ = 0 otherwise. Models specify the Excess Relative Risk ERR as a function of Dφ while controlling for gender, log attained age, and age-at-exposure categories. Control: ERR = 0 Linear: ERR = βDφ; control model nested by β = 0. Transient: ERR = σDφ e(-τDφ) with τ ≥ 0; linear model nested by τ = 0. Two-phase: ERR = βDφ + σDφ e(-τDφ) with τ ≥ 0; linear model nested by σ = 0; transient model nested by β = 0.

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