ASAT             package:exactRankTests             R Documentation

_T_o_x_i_c_o_l_o_g_i_c_a_l _S_t_u_d_y _o_n _F_e_m_a_l_e _W_i_s_t_a_r _R_a_t_s

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

     ASAT-Values for a new compound and a control group of 34 female
     Wistar rats.

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

     data(ASAT)

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

     A data frame with 34 observations on the following 2 variables.

     _a_s_a_t the ASAT-values (a liver enzyme)

     _g_r_o_u_p a factor with levels 'Compound' and 'Control'.

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

     The aim of this toxicological study is the proof of safety for the
     new compound. The data are originally given in Hothorn (1992) and
     reproduced in Hauschke et al. (1999).

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

     Ludwig A. Hothorn (1992), Biometrische Analyse toxikologischer
     Untersuchungen. In: J. Adams (ed.): _Statistisches Know how in der
     medizinischen  Forschung._ Ullstein-Mosby, Berlin, 475-590.

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

     Dieter Hauschke, Meinhard Kieser & Ludwig A. Hothorn (1999), 
     Proof of safety in toxicology based on the ratio of two means for
     normally distributed data. _Biometrical Journal_, *41*(3),
     295-304.

     Rafael Pfl{\"u}ger & Torsten Hothorn (2002), Assessing Equivalence
     Tests with Respect to their Expected $p$-Value. _Biometrical
     Journal_, *44*(8), 1002-1027.

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

     data(ASAT)
     # does not really look symmetric

     plot(asat ~ group, data=ASAT)

     # proof-of-safety based on ration of medians
     pos <- wilcox.exact(I(log(asat)) ~ group, data = ASAT, alternative = "less", 
                  conf.int=TRUE)

     # one-sided confidence set. Safety cannot be concluded since the effect of
     # the compound exceeds 20% of the control median
     exp(pos$conf.int)

