Coefficient         Estimate         SE         z value INTERCEPT –3.0478 0.5624 –5.42 TREAT –0.6265 0.3239 –1.93 NUMBER 0.2485 0.0867  2.87 SIZE –0.0176 0.1086 –0.16 0.9221 0.3441 2.68

Table 3: Analysis of bladder cancer data using a proportional hazards model with a shared frailty.