

birthwt(boot)                                R Documentation

_R_i_s_k _F_a_c_t_o_r_s _f_o_r _L_o_w _B_i_r_t_h _W_e_i_g_h_t

_A_r_g_u_m_e_n_t_s_:

     low: Indicator of low birth weight; `1' indicates low
          birth weight (< 2.5kg), `0' indicates normal birth
          weight.

     age: Mother's age in years at the time of birth.

     lwt: The mother's weight (in pounds) at the time of the
          last menstrual period.

    race: A factor for the mother's race. Levels are `1'
          (white), `2' (black) and `3' (other).

   smoke: Indicator of mother's smoking status; `1'=smoker,
          `0'=non-smoker.

     ptl: Number of previous premature labours.

      ht: Indicator of hypertension history; `1'=yes,
          `0'=no.

      ui: Indicator of the presence of uterine irritability;
          `1'=yes, `0'=no.

     ftv: Number of physician visits during the first
          trimester

     bwt: Infant's birth weight in grams

_S_U_M_M_A_R_Y_:

     The `birthwt' data frame has 189 rows and 10 columns.

     Data was collected at the Baystate Medical Center,
     Springfield, Massachusetts during 1986 to attempt to
     identify which factors contributed to an increased risk
     of low birth weight infants.  Information was recorded
     for 189 women of whom 59 had low birth weight infants.

_D_A_T_A _D_E_S_C_R_I_P_T_I_O_N_:

     This data frame contains the following columns:

_S_O_U_R_C_E_:

     The data were obtained from

     Hosmer, D.W. and Lemeshow, S. (1989) Applied Logistic
     Regression.  John Wiley.

_O_T_H_E_R _R_E_F_E_R_E_N_C_E_S_:

     Davison, A.C. and Hinkley, D.V. (1997) Bootstrap Meth-
     ods and Their Application. Cambridge University Press.

     Venables, W.N. and Ripley, B.D. (1994) Modern Applied
     Statistics with S-Plus. Springer-Verlag.

