% Generated by roxygen2: do not edit by hand

% Please edit documentation in R/study_constructors.R

\name{Study}

\alias{Study}

\title{Constructor for a Study}

\usage{

Study(alpha, power, HR, r, N, study.duration, ctrl.median, k, acc.period,

  two.sided, shape = 1, dropout = NULL, lag.settings = NullLag())

}

\arguments{

\item{alpha}{Significance level [0,1] (see also two-sided indicator)}

\item{power}{Power [0,1]}

\item{HR}{Hazard ratio to be detected}

\item{r}{Control:Experimental subject balance (1:r), i.e. nE/nC=r. r=1 corresponds to equally 

many subjects in both arms. 2 means we have twice the number of subjects in the experimental arm.}

\item{N}{Number of subjects to be recruit (integer)}

\item{study.duration}{Number of months the study will be going.}

\item{ctrl.median}{Median time to an event in the control group.}

\item{k}{non-uniformity of accrual (integer, 1=uniform). Non-uniform accrual is allowed for 

using the following distribution for the probability of a patient entering the trial at time \eqn{b} 

within the accrual period \eqn{[0,B]}: \eqn{F(b)=b_k/B_k}; \eqn{f(b)=k b_{k-1}/B_k} where \eqn{k} is the 

measure of non-uniformity (\eqn{k>0}). \eqn{k=1} indicates uniform accrual. This implies that during 

the first half of the accrual period, \eqn{1/2^k} of the patients will be recruited. Half of the patients 

will be recruited by time \eqn{B/2^{1/k}}.}

\item{acc.period}{Accrual time.}

\item{two.sided}{If TRUE, two sided test will be used (i.e. alpha/2).}

\item{shape}{The Weibull shape parameter}

\item{dropout}{if subjects drop out in study (due to competing risks not as there is a finite follow up time)

then this argument should contain a list with proportion and time and optionally shape i.e.

\code{dropout=list(proportion=0.03,time=12,shape=1.2)} meaning in the absence of events 3% of subjects

will have dropped out after 12 months with a Weibull hazard rate with shape=1.2. If shape is not included then 

it defaults to 1 (exponential rate). If dropout is NULL then no subjects will drop out}

\item{lag.settings}{The \code{LaggedEffect} object describing any lag effect for the study}

}

\description{

Constructor for a Study

}