Table 2.

Constrained maximum likelihood parameter estimates for the basic four-parameter dose–response model

Parameter	Estimate	Bootstrap median	Bootstrap lower bound (2.5th percentile)	Bootstrap upper bound (97.5th percentile)
DS86 (maximum log-likelihood =  − 502.60)a
θ1—intercept (%)	1.25	1.24	1.08	1.41
θ2—initial slope (% / mGy)	0.031	0.034	0.0	0.107
θ3—downturn (mGy−1)	0.032	0.032	0.028	0.049
θ4—overall slope (% / Gy)	0.421	0.436	0.0	1.26
DS02R1 (maximum log-likelihood =  − 503.18)
θ1—intercept (%)	1.26	1.25	1.08	1.41
θ2—initial slope (% / mGy)	0.037	0.035	0.0	0.156
θ3—downturn (mGy−1)	0.042	0.042	0.032	0.057
θ4—overall slope (% / Gy)	0.451	0.456	0.0	1.33

The model is that of Eq. (1)

^aCorresponding estimates (95% CI) of the four parameters reported by Ohtaki et al. (2004) were 1.2 (1.1, 1.4) %, 0.038 (0, 0.103) %/mSv, 0.0335 (0.007, 0.0655) /mSv, and 0.5 (0, 1.4) %/Sv, respectively