metacont                package:meta                R Documentation

_M_e_t_a-_a_n_a_l_y_s_i_s _o_f _c_o_n_t_i_n_u_o_u_s _o_u_t_c_o_m_e _d_a_t_a

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

     Calculation of fixed and random effects estimates for
     meta-analyses with continuous outcome data; inverse variance
     weighting is used for pooling.

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

     metacont(n.e, mean.e, sd.e, n.c, mean.c, sd.c, studlab,
              data=NULL, subset=NULL, sm="WMD")

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

     n.e: Number of observations in experimental group.

  mean.e: Estimated mean in experimental group.

    sd.e: Standard deviation in experimental group.

     n.c: Number of observations in control group.

  mean.c: Estimated mean in control group.

    sd.c: Standard deviation in control group.

 studlab: An optional vector with study labels.

    data: An optional data frame containing the study information,
          i.e., n.e, mean.e, sd.e, n.c, mean.c, and n.c.

  subset: An optional vector specifying a subset of studies to be used.

      sm: A character string indicating which summary measure ('"WMD"'
          or '"SMD"') is to be used for pooling of studies.

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

     Calculation of fixed and random effects estimates for
     meta-analyses with continuous outcome data; inverse variance
     weighting is used for pooling. The DerSimonian-Laird estimate is
     used in the random effects model. For the summary measure '"SMD"',
     Hedges' adjusted g is utilised for pooling.

     The function 'metagen' is called internally to calculate
     individual and overall treatment estimates and standard errors.

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

     An object of class 'c("metacont", "meta")' with corresponding
     'print', 'summary', 'plot' function. The object is a list
     containing the following components: 

n.e, mean.e, sd.e,: 

n.c, mean.c, sd.c,: As defined above.

studlab, sm: 

TE, seTE: Estimated treatment effect and standard error of individual
          studies.

w.fixed, w.random: Weight of indiviudal studies (in fixed and random
          effects model).

TE.fixed, seTE.fixed: Estimated overall treatment effect and standard
          error (fixed effect model).

TE.random, seTE.random: Estimated overall treatment effect and standard
          error (random effects model).

       k: Number of studies combined in meta-analysis.

       Q: Heterogeneity statistic.

     tau: Square-root of between-study variance (moment estimator of
          DerSimonian-Laird).

  method: Pooling method: '"Inverse"'.

    call: Function call.

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

     Guido Schwarzer sc@imbi.uni-freiburg.de

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

     Cooper H & Hedges LV (1994), _The Handbook of Research Synthesis_.
     Newbury Park, CA: Russell Sage Foundation.

_S_e_e _A_l_s_o:

     'metabin', 'metagen'

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

     data(Fleiss93cont)
     meta1 <- metacont(n.e, mean.e, sd.e, n.c, mean.c, sd.c, data=Fleiss93cont, sm="SMD")
     meta1

     meta2 <- metacont(Fleiss93cont$n.e, Fleiss93cont$mean.e,
                       Fleiss93cont$sd.e,
                       Fleiss93cont$n.c, Fleiss93cont$mean.c,
                       Fleiss93cont$sd.c,
                       sm="SMD")
     meta2

