| anova {JM} | R Documentation |
Performs a likelihood ratio test between two nested joint models.
## S3 method for class 'jointModel': anova(object, object2, test = TRUE, ...)
object |
an object inheriting from class jointModel, nested in object2. |
object2 |
an object inheriting from class jointModel. |
test |
logical; if TRUE the likelihood ratio test is performed. |
... |
additional arguments; currently none is used. |
An object of class aov.jointModel with components,
nam0 |
the name of object. |
L0 |
the log-likelihood under the null hypothesis (object). |
aic0 |
the AIC value for the model given by object. |
bic0 |
the BIC value for the model given by object. |
nam1 |
the name of object2. |
L1 |
the log-likelihood under the alternative hypothesis (object2). |
aic1 |
the AIC value for the model given by object2. |
bic1 |
the BIC value for the model given by object2. |
df |
the degrees of freedom for the test (i.e., the difference in the number of parameters). |
LRT |
the value of the Likelihood Ratio Test statistic (returned if test = TRUE). |
p.value |
the p-value of the test (returned if test = TRUE). |
The code minimally checks whether the models are nested! The user is responsible to supply nested models in order the LRT to be valid.
Dimitris Rizopoulos d.rizopoulos@erasmusmc.nl
# linear mixed model fit without treatment effect
fitLME.null <- lme(sqrt(CD4) ~ obstime,
random = ~ 1 | patient, data = aids)
# cox model fit without treatment effect
fitCOX.null <- coxph(Surv(Time, death) ~ 1,
data = aids.id, x = TRUE)
# joint model fit, under the additive log cumulative hazard model
# without treatment effect
fitJOINT.null <- jointModel(fitLME.null, fitCOX.null,
timeVar = "obstime", method = "ch-GH")
# linear mixed model fit with treatment effect
fitLME.alt <- lme(sqrt(CD4) ~ obstime * drug - drug,
random = ~ 1 | patient, data = aids)
# cox model fit with treatment effect
fitCOX.alt <- coxph(Surv(Time, death) ~ drug,
data = aids.id, x = TRUE)
# joint model fit, under the additive log cumulative hazard model
# with treatment effect
fitJOINT.alt <- jointModel(fitLME.alt, fitCOX.alt, timeVar = "obstime",
method = "ch-GH")
# likelihood ratio test for treatment effect
anova(fitJOINT.null, fitJOINT.alt)