Table 1.

Pre-flight Ex Vivo poisson regression parameter estimates (“Est.”) and standard errors (“SE”) based on all pre-flight observations with dose ≤ 0.5 Gy. The “Z”-value is the signal-to-noise ratio (Est/SE), while “p” is the p value for the test of the null hypothesis that the parameter is zero. In the fitted model, mean log CAR increases by about 0.0415 (4.151/100) per cGy of gamma radiation, corresponding to about a 4% increase in median CAR per cGy of increased radiation. Similarly, all other things being equal, median background CAR increases by about 3% per year of age. There could also be a gender effect, but there were not enough female subjects to accurately estimate it. Results presented in this and the other tables were generated using Stata Statistical Software²⁷.

Pre-flight model parameter	Equation 2 predictor variable	Est	SE	Z-value	p
β1	xij (γ-ray dose)	4.151	0.168	24.72	0
β2	A50i	0.029	0.012	2.42	0.016
β3	Fi	0.168	0.118	1.43	0.153
β4	1	− 5.717	0.084	− 68.2	0