dosresmeta.fixed {dosresmeta}

Fixed-Effects Estimator for dosresmeta Models

Description

This function implements a generalized least square estimator for fixed-effects dose-response meta-analysis. It is meant to be used internally and not directly run by the users.

Usage

dosresmeta.fixed(Xlist, Zlist, ylist, Slist, nalist, q, nall, control, ...)

Arguments

Xlist

a m-dimensional list of study-specific design matrices for the fixed-effects part of the model.

Zlist

a m-dimensional list of study-specific design matrices for the random-effects part of the model.

ylist

a m-dimensional list of study-specific of vectors of estimated outcomes.

Slist

a m-dimensional list of within-study (co)variance matrices of estimated outcomes.

nalist

a m-dimensional list of k-dimensional study-specific logical vectors, identifying missing outcomes.

q, nall

numeric scalars: number of predictors, number of observations (excluding missing).

control

list of parameters for controlling the fitting process, usually internally set to default values by dosresmeta.control.

...

further arguments passed to or from other methods. Currently not used.

Details

The estimation involves only the p fixed-effects coefficients. The routine is based on a standard generalized least square (GLS) algorithm implemented in the internal function glsfit. The between-study (co)variance matrix is set to zero, so the marginal (co)variance matrix, composed only by elements of the within-study component, is assumed as completely known. Similarly to the likelihood-based estimators implemented in dosresmeta.ml and dosresmeta.reml, the computation involves Cholesky and and QR decompositions for computational stability and efficiency.

Value

This function returns an intermediate list object, whose components are then processed by dosresmeta.fit. Other components are added later through mvmeta to finalize an object of class "dosresmeta".

Author(s)

Alessio Crippa, [e-mail]

References

Gasparrini, A., Armstrong, B., Kenward, M. G. (2012). Multivariate meta-analysis for non-linear and other multi-parameter associations. Statistics in Medicine, 31(29), 3821-3839.

See Also

dosresmeta, dosresmeta-package, dosresmeta.ml

Examples

data("alcohol_crc")

## Fixed-effect dose-response model assuming linearity
dosresmeta(formula = logrr ~ dose, type = type, id = id, se = se, 
           cases = cases, n = peryears, data = alcohol_crc, method = "fixed")