λ0(t) ≡ λ0   θ Cens. %              t1 : S(t1) = 0.75             t2 : S(t2) = 0.5 Gamma Frailty Ignoring Frailty Gamma Frailty Ignoring Frailty Bias SE Bias SE Bias SE Bias SE 0.01 1.64 10% .0003 .0099 .0001 .0137 .0001 .0054 .0003 .0136 0.01 1.64 30% .0002 .0112 .0007 .0157 .0001 .0062 .0001 .0155 0.01 0.5 10% .0001 .0130 .0001 .0138 .0006 .0107 .0008 .0136 0.01 0.5 30% .0001 .0151 .0000 .0155 .0002 .0125 .0004 .0159 0.1 1.64 10% .0004 .0099 .0007 .0140 .0004 .0054 .0002 .0140 0.1 1.64 30% .0003 .0114 .0005 .0156 .0004 .0061 .0012 .0156 0.1 0.5 10% .0005 .0133 .0006 .0140 .0000 .0105 .0007 .0131 0.1 0.5 30% .0004 .0157 .0001 .0162 .0002 .0127 .0000 .0159 1.0 1.64 10% .0000 .0103 .0004 .0135 .0005 .0053 .0005 .0134 1.0 1.64 30% .0004 .0116 .0003 .0157 .0002 .0062 .0002 .0147 1.0 0.5 10% .0003 .0131 .0004 .0141 .0002 .0110 .0003 .0135 1.0 0.5 30% .0009 .0148 .0007 .0159 .0002 .0134 .0000 .0167

Table 1: Estimation of attributable fractions in simulated clustered survival data: β = 0.