mediation using categorical variables with lavaan

[Paul Joseph]

how do i interpret mediation categorical outcomes with lavaan especially the estimates and threshold. 

[Paul Joseph]

Hi group, my mediation analysis using categorical variables shows one of the variables had negative variance. what does it implies? how do i explain threshold output. the output is below:

  Estimator                                       DWLS

  Optimization method                           NLMINB

  Number of free parameters                         14

                                                      

  Number of observations                           477

                                                     

Model Test User Model:

                                              Standard      Robust

  Test Statistic                               202.835     187.889

  Degrees of freedom                                 6           6

  P-value (Chi-square)                           0.000       0.000

  Scaling correction factor                                  1.082

  Shift parameter                                            0.456

       simple second-order correction                            

 

Parameter Estimates:

 

  Standard errors                           Robust.sem

  Information                                 Expected

  Information saturated (h1) model        Unstructured

 

Regressions:

                   Estimate  Std.Err  z-value  P(>|z|)

  exbrest ~                                          

    medul      (a)   -0.081    0.052   -1.568    0.117

  cmortm ~                                           

    exbrest    (b)   -0.282    0.077   -3.678    0.000

  waterm ~                                           

    medul      (d)   -0.197    0.057   -3.445    0.001

  cmortm ~                                           

    waterm     (e)   -0.583    0.058  -10.035    0.000

    medul      (c)   -0.125    0.073   -1.718    0.086

  hospdel ~                                          

    medul      (f)   -0.166    0.062   -2.678    0.007

  cmortm ~                                           

    hospdel    (g)   -0.410    0.065   -6.302    0.000

  wsystem1 ~                                         

    medul      (h)   -0.318    0.055   -5.748    0.000

  cmortm ~                                            

    wsystem1   (i)   -0.696    0.048  -14.519    0.000

 

Intercepts:

                   Estimate  Std.Err  z-value  P(>|z|)

   .exbrest           0.000                          

   .cmortm            0.000                          

   .waterm            0.000                          

   .hospdel           0.000                          

   .wsystem1          0.000                          

 

Thresholds:

                   Estimate  Std.Err  z-value  P(>|z|)

    exbrest|t1       -1.009    0.204   -4.935    0.000

    cmortm|t1         0.910    0.195    4.674    0.000

    waterm|t1        -1.251    0.234   -5.340    0.000

    hospdel|t1       -1.278    0.252   -5.078    0.000

    wsystem1|t1      -1.269    0.234   -5.419    0.000

 

Variances:

                   Estimate  Std.Err  z-value  P(>|z|)

   .exbrest           1.000                          

   .cmortm           -0.072                          

   .waterm            1.000                           

   .hospdel           1.000                          

   .wsystem1          1.000                          

 

Scales y*:

                   Estimate  Std.Err  z-value  P(>|z|)

    exbrest           1.000                          

    cmortm            1.000                          

    waterm            1.000                          

    hospdel           1.000                          

    wsystem1          1.000                          

 

Defined Parameters:

                   Estimate  Std.Err  z-value  P(>|z|)

    ab                0.023    0.016    1.438    0.150

    de                0.115    0.035    3.235    0.001

    fg                0.068    0.028    2.422    0.015

    hi                0.221    0.041    5.389    0.000

    total             0.302    0.047    6.485    0.000