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fixef.mjoint

Extract fixed effects estimates from an mjoint object


Description

Extract fixed effects estimates from an mjoint object.

Usage

## S3 method for class 'mjoint'
fixef(object, process = c("Longitudinal", "Event"), ...)

Arguments

object

an object inheriting from class mjoint for a joint model of time-to-event and multivariate longitudinal data.

process

character string: if process='Longitudinal' the fixed effects coefficients from the (multivariate) longitudinal sub-model are returned. Else, if process='Event', the coefficients from the time-to-event sub-model are returned.

...

additional arguments; currently none are used.

Value

A named vector of length equal to the number of sub-model coefficients estimated.

Author(s)

Graeme L. Hickey (graemeleehickey@gmail.com)

References

Pinheiro JC, Bates DM. Mixed-Effects Models in S and S-PLUS. New York: Springer Verlag; 2000.

Wulfsohn MS, Tsiatis AA. A joint model for survival and longitudinal data measured with error. Biometrics. 1997; 53(1): 330-339.

See Also

fixef for the generic method description, and ranef.mjoint.

Examples

# Fit a classical univariate joint model with a single longitudinal outcome
# and a single time-to-event outcome

data(heart.valve)
hvd <- heart.valve[!is.na(heart.valve$log.grad) & !is.na(heart.valve$log.lvmi), ]

set.seed(1)
fit1 <- mjoint(formLongFixed = log.lvmi ~ time + age,
    formLongRandom = ~ time | num,
    formSurv = Surv(fuyrs, status) ~ age,
    data = hvd,
    timeVar = "time",
    control = list(nMCscale = 2, burnin = 5)) # controls for illustration only

fixef(fit1, process = "Longitudinal")
fixef(fit1, process = "Event")

## Not run: 
# Fit a joint model with bivariate longitudinal outcomes

data(heart.valve)
hvd <- heart.valve[!is.na(heart.valve$log.grad) & !is.na(heart.valve$log.lvmi), ]

fit2 <- mjoint(
    formLongFixed = list("grad" = log.grad ~ time + sex + hs,
                         "lvmi" = log.lvmi ~ time + sex),
    formLongRandom = list("grad" = ~ 1 | num,
                          "lvmi" = ~ time | num),
    formSurv = Surv(fuyrs, status) ~ age,
    data = list(hvd, hvd),
    inits = list("gamma" = c(0.11, 1.51, 0.80)),
    timeVar = "time",
    verbose = TRUE)

fixef(fit2, process = "Longitudinal")
fixef(fit2, process = "Event")

## End(Not run)

joineRML

Joint Modelling of Multivariate Longitudinal Data and Time-to-Event Outcomes

v0.4.5
GPL-3 | file LICENSE
Authors
Graeme L. Hickey [cre, aut] (<https://orcid.org/0000-0002-4989-0054>), Pete Philipson [aut] (<https://orcid.org/0000-0001-7846-0208>), Andrea Jorgensen [ctb] (<https://orcid.org/0000-0002-6977-9337>), Ruwanthi Kolamunnage-Dona [aut] (<https://orcid.org/0000-0003-3886-6208>), Paula Williamson [ctb] (<https://orcid.org/0000-0001-9802-6636>), Dimitris Rizopoulos [ctb, dtc] (data/renal.rda, R/hessian.R, R/vcov.R), Alessandro Gasparini [aut] (<https://orcid.org/0000-0002-8319-7624>), Medical Research Council [fnd] (Grant number: MR/M013227/1)
Initial release
2021-04-21

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