make.swt: Simulates a 'virtual' Stepped Wedge trial

In giabaio/SWSamp: Computes Sample Size for a Stepped Wedge Design, using Simulation-Based Calculations

Simulates a 'virtual' Stepped Wedge trial

Description

Simulates trial data for a SWT with normally distributed outcome

Usage

make.swt(
  I = NULL,
  J = NULL,
  H = NULL,
  K,
  design = "cross-sec",
  mu = NULL,
  b.trt,
  b.time = NULL,
  sigma.y = NULL,
  sigma.e = NULL,
  rho,
  sigma.a = NULL,
  rho.ind = NULL,
  sigma.v = NULL,
  X = NULL,
  family = "gaussian",
  natural.scale = TRUE
)

Arguments

I	Number of clusters
J	Number of time points
H	Number of units randomised at each time point
K	Average size of each cluster
design	type of design. Can be 'cross-sec' (default) or 'cohort' (repeated measurements)
mu	baseline outcome value
b.trt	Treatment effect
b.time	Time effect
sigma.y	total standard deviation
sigma.e	individual standard deviation
rho	Intra-class correlation coefficient
sigma.a	the sd of the the cluster-level intercept (default at NULL)
rho.ind	individual-level ICC (for cohorts)
sigma.v	the sd of the cluster-level slope (by intervention, default at NULL)
X	A design matrix for the SWT. Default at NULL (will be computed automatically)
family	The model family to be used. Default value is 'gaussian' and other possibile choices are 'binomial' or 'poisson'
natural.scale	Indicator for whether the input is passed on the natural scale or on the scale of the linear predictor. By default is set to TRUE. In the case of family='gaussian' it does not have any effect, since the link for the linear predictor is the identity. But for family='binomial' or family='poisson', the user has to specify when the input is given on the logit or log scale

Value

data	A data frame containing the resulting simulated dataset

Author(s)

Gianluca Baio, Rosie Leach

References

Baio, G; Copas, A; Ambler, G; Hargreaves, J; Beard, E; and Omar, RZ Sample size calculation for a stepped wedge trial. Trials, 16:354. Aug 2015.

See Also

See Also sim.power

giabaio/SWSamp documentation built on Nov. 14, 2022, 2:24 p.m.