### Mediator model

Call:
lm(formula = bili ~ trt, data = data)

Residuals:
    Min      1Q  Median      3Q     Max 
-3.4000 -2.5000 -1.7000  0.4434 24.3000 

Coefficients:
            Estimate Std. Error t value Pr(>|t|)  
(Intercept)   2.2132     0.8784   2.520   0.0123 *
trt           0.7434     0.5532   1.344   0.1801  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 4.594 on 274 degrees of freedom
Multiple R-squared:  0.006548,	Adjusted R-squared:  0.002923 
F-statistic: 1.806 on 1 and 274 DF,  p-value: 0.1801

### Outcome model

Call:
MASS::glm.nb(formula = platelet ~ trt + bili, data = data, init.theta = 7.565462089, 
    link = log)

Coefficients:
             Estimate Std. Error z value Pr(>|z|)    
(Intercept)  5.537521   0.071332  77.630   <2e-16 ***
trt          0.033034   0.044547   0.742    0.458    
bili        -0.006098   0.004854  -1.256    0.209    
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

(Dispersion parameter for Negative Binomial(7.5655) family taken to be 1)

    Null deviance: 284.50  on 275  degrees of freedom
Residual deviance: 282.52  on 273  degrees of freedom
AIC: 3288.8

Number of Fisher Scoring iterations: 1


              Theta:  7.565 
          Std. Err.:  0.652 

 2 x log-likelihood:  -3280.822 
### Mediation analysis 
              est          se          Z         p       lower       upper
cde   0.039640606 0.053456352  0.7415509 0.4583595 -0.06513192 0.144413130
pnde  0.039640606 0.053456352  0.7415509 0.4583595 -0.06513192 0.144413130
tnie -0.005439403 0.005927448 -0.9176636 0.3587950 -0.01705699 0.006178181
tnde  0.039640606 0.053456352  0.7415509 0.4583595 -0.06513192 0.144413130
pnie -0.005439403 0.005927448 -0.9176636 0.3587950 -0.01705699 0.006178181
te    0.034201203 0.053435418  0.6400474 0.5221418 -0.07053029 0.138932698
pm   -0.162217272 0.313168047 -0.5179879 0.6044667 -0.77601537 0.451580821
      exp(est) exp(lower) exp(upper)
cde  1.0404368  0.9369439   1.155361
pnde 1.0404368  0.9369439   1.155361
tnie 0.9945754  0.9830877   1.006197
tnde 1.0404368  0.9369439   1.155361
pnie 0.9945754  0.9830877   1.006197
te   1.0347928  0.9318995   1.149047
pm          NA         NA         NA

Evaluated at:
avar: trt
 a1 (intervened value of avar) = 2.3
 a0 (reference value of avar)  = 1.1
mvar: bili
 m_cde (intervend value of mvar for cde) = 1.4
cvar: 
 c_cond (covariate vector value) = 

Note that effect estimates do not vary over m_cde and c_cond values when interaction = FALSE.