Model     b1     b2 r m s2 k r ll* p-value# H0 0.7993 (0.72´10-7) 0.2698 (0.87´10-7) - 3.7967 (0.33 ´10-6) 0.0417 (0.38 ´10-5) 5.2930 (0.0038) 0.9412 (0.0003) -305.7977 0.5903 H1 0.7993 (0.0009) 0.2739 (0.0006) -0.0039 (0.0048) 3.7966 (0.0265) 0.0414 (0.0035) 5.2938 (0.0231) 0.9305 (0.0266) -305.6527 *, Loglikelihood; #, The p-value of the loglikelihood ratio test

Table 1: Parameter estimates and their standard errors for two different models. The numbers in parentheses are the standard error of the estimates. The null hypothesis (H0) is when two sensitivities are independent (r = 0) and the alternative hypothesis (H1) is when two sensitivities are not independent (r ? 0). The estimated sensitivity for the dual screening (ß) is 0.8534 and 0.8550 for H0 and H1, respectively.