leprosy1               package:missreg               R Documentation

_T_h_e _L_e_p_r_o_s_y _d_a_t_a

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

     The leprosy data set was described in Scott and Wild (1997, 2001)
     and  used as an example of standard two-phase case-control sampled
     data.

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

     data(leprosy1)

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

     A data frame with 42 observations on the following 5 variables.

     '_l_e_p_r_o_s_y' a factor with levels 'no' 'yes'

     '_a_g_e' a numeric vector indicating the mid-point of six 5-year age
          groups

     '_s_c_a_r' a factor with levels 'no' 'yes'

     '_c_o_u_n_t_s' a numeric vector indicating number of subjects with each
          observation

     '_o_b_s_t_y_p_e' a factor with levels 'retro' and 'strata', compulsory
          for function call

_D_e_t_a_i_l_s:

     The leprosy data were obtained by sampling from the results of a
     population cross-sectional study of people under 35 in Northern
     Malawi and represented as  a three-way contingency table in
     Clayton and Hills (1993). Those people with leprosy were defined
     to be cases and the rest to be controls. The data were first
     categorized into six 5-year age sampling strata and the numbers of
     cases and controls falling into each stratum were observed. All
     cases have been chosen with an equal-sized control group
     subsampled from the control population within each age stratum.
     The potential  risk factor that indicates the presence or absence
     of a BCG vaccination scar was then observed. 

      The data are represented in three different formats in
     'leprosy1',  'leprosy2' and 'leprosy3'. See "Description of the
     'missreg' Library" for more details.

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

     Description of the 'missreg' Library, Wild and Jiang, 2007

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

     data(leprosy1)

