seizures              package:DPpackage              R Documentation

_E_p_i_l_e_p_t_i_c _s_e_i_z_u_r_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     This data set consider information from a clinical trial of 59
     epileptics, reported by Thall and Vail (1990). For each patient,
     the number of epileptic seizures was recorded during a baseline
     period of eight weeks. Patients were then randomized to treatment
     with the anti-epileptic drug progabide, or to aplacebo in addition
     to standard chemotherapy. The number of seizures was then recorded
     in four consecutive two-weeks intervals.

_U_s_a_g_e:

     data(seizures)

_F_o_r_m_a_t:

     A data frame with 295 observations on the following 5 variables.

     '_i_d' an ordered factor giving a unique identifier for the subject
          in the study.

     '_s_e_i_z_e' a numeric vector giving the number of epileptic seizures.

     '_v_i_s_i_t' a numeric vector giving the number of the visit,
          0=baseline, and 1,2,3, and 4 for the four consecutive
          two-weeks intervals.

     '_t_r_t' a numeric vector giving the treatment group.

     '_a_g_e' a numeric vector giving the age at the entry.

_S_o_u_r_c_e:

     Thall, P.F., and Vail, S.C. (1990) Some covariance models for
     longitudinal count data with ovserdispersion, Biometrics, 46:
     657-671.

_R_e_f_e_r_e_n_c_e_s:

     Diggle, P.J., Liang, K-Y., and Zeger, S.L. (1994) Analysis of
     longitudinal data. Oxford: Clarendon Press.

_E_x_a_m_p_l_e_s:

     data(seizures)
     ## maybe str(seizures) ; plot(seizures) ...

