poly3est                package:MCPAN                R Documentation

_O_n_l_y _f_o_r _i_n_t_e_r_n_a_l _u_s_e.

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

     Poly-3- adjusted point and variance estimates for long term
     carcinogenicity data

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

     poly3est(time, status, tmax, method = "BP", k=NULL)

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

    time: a numeric vector of times of death of the individuals

  status: a logical (or numeric, consisting of 0,1 only) vector giving
          the tumour status at time of death of each individual, where
          TRUE (1) = tumour present, FALSE (0) = no tumour present  

    tmax: a single numeric vector, the final time of the trial 

  method: a single charcter string, specifying the method for
          adjustment, with options: "BP" (Bailer Portier: assuming
          poly-3-adjusted rates are binomial variables), "BW" (Bieler,
          Williams: delta method as in Bieler-Williams (1993)) "ADD1"
          (as Bailer Portier, including an add1-adjustment on the raw
          tumour rates) "ADD2" (as Bailer Portier, including an
          add2-adjustment on the raw tumour rates following Agresti
          Caffo (2000) for binomials) 

       k: a single numeric value, adjustment according to Bailer and
          Portier (1988), defaults to 3

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

     Only for internal use of 'poly3test' and 'poly3ci'.

_V_a_l_u_e:

     A list containing: 

      Y : number of tumours

       n: number of individuals

estimate: poly-3-adjusted rates according to Bailer, Portier (1988)

  weight: a vector of poly-3-adjusted weights, of length n 

    estp: poly-3-adjusted rate (according to method)

    nadj: adjusted n (sum of weights)

    varp: variance estimate (according to method)

  varcor: variance estimate, if necessary corrected such that estimates
          of 0 can not occur

_N_o_t_e:

     Please note, that appropriateness of the point estimates seriously
     depends on whether the assumptions in Bailer and Portier are met
     or not.

_A_u_t_h_o_r(_s):

     Frank Schaarschmidt

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

     Bailer, J.A. and Portier, C.J. (1988): Effects of
     treatment-induced mortality and tumor-induced mortality on tests
     for carcinogenicity in small samples. Biometrics 44, 417-431.

