rats package:survival R Documentation _R_a_t _d_a_t_a _f_r_o_m _s_u_r_v_i_v_a_l_5 _D_e_s_c_r_i_p_t_i_o_n: 48 rats were injected with a carcinogen, and then randomized to either drug or placebo. The number of tumors ranges from 0 to 13; all rats were censored at 6 months after randomization. _U_s_a_g_e: data(rats) _F_o_r_m_a_t: rat: id rx: treatment,(1=drug, 0=control) observation: within rat start: entry time stop: exit time status: event status _S_o_u_r_c_e: Gail, Sautner and Brown, Biometrics 36, 255-66, 1980