fcut1                  package:Epi                  R Documentation

_C_u_t _f_o_l_l_o_w-_u_p _t_i_m_e _a_t _a _f_a_i_l_u_r_e _t_i_m_e.

_D_e_s_c_r_i_p_t_i_o_n:

     This function cuts the follow-up time at a failure allowing a
     person to stay at risk after the failure. It is aimed at
     processing of recurrent events. Failure times outside the interval
     ('enter','exit') are ignored.

_U_s_a_g_e:

     fcut1( enter, exit, fail, dof, fail.value = 1, 
              data = data.frame(enter, exit, fail, dof),
            Expand = 1:nrow(data) )

_A_r_g_u_m_e_n_t_s:

   enter: Date of entry into the study. Numerical vector.

    exit: Date of exit from the study. Numerical vector.

    fail: Failure indicator for the exit date.

     dof: Date of failure. Numerical vector. Missing for persons who do
          not have an event.

fail.value: Value for failure indicator 'Fail' at the date 'dof'.

    data: Dataframe of variables to be carried unchanged to the output.

  Expand: Variable identifying original records.

_V_a_l_u_e:

     A dataframe with the same columns as in 'data', preceded by the
     columns: 

  Expand: Identification of the rows from the input dataframe.

   Enter: Entry date for the interval.

    Exit: Exit date for the interval.

    Fail: Failure indicator for the interval.

_A_u_t_h_o_r(_s):

     Bendix Carstensen, Steno Diabetes Center, bxc@steno.dk, <URL:
     www.biostat.ku.dk/~bxc>

_S_e_e _A_l_s_o:

     'Lexis', 'isec', 'fcut1', 'fcut', 'ex1'

_E_x_a_m_p_l_e_s:

     one <- round( runif( 15, 0, 10 ), 1 )
     two <- round( runif( 15, 0, 10 ), 1 )
     doe <- pmin( one, two )
     dox <- pmax( one, two )
     # Goofy data rows to test possibly odd behaviour
     doe[1:3] <- dox[1:3] <- 8
     dox[2] <- 6
     dox[3] <- 7.5
     # Some failure indicators and failure times
     fail <- sample( 0:1, 15, replace=TRUE, prob=c(0.7,0.3) )
     dof <- sample( c(one,two), 15 )
     # So what have we got
     data.frame( doe, dox, fail, dof )
     # Cut follow-up at dof
     fcut1( doe, dox, fail, dof )

