How to Line up all patients by their final time in R

Question

I have a longitudinal data which included 1000 patients and four variables. These variables are repeatedly measured over time. The time differs across patients. My question is how to line up all patients by their final time in R?
Here an example of the data :

    dput(head(mydata))
structure(list(Enum = c(15306L, 15306L, 15306L, 15306L, 11056L, 
    11056L), Sex = c(0L, 0L, 0L, 0L, 1L, 1L), Left_R = c(1L, 1L, 
    1L, 1L, 0L, 0L), Right_R = c(1L, 1L, 1L, 1L, 0L, 0L), risk = c(2, 
    1.5, 1.5, 1.5, 0, 0), Chol_val = c(4.1, 3.7, 3.9, 3.7, 5.2, 3.6
    ), HbA1c_val = c(39L, 41L, 43L, 39L, 39L, 45L), eGFR_val = c(90, 
    NA, 90, 85, 82, 85), Duration = c(3682L, 3682L, 3682L, 3682L, 
    36L, 36L), Age = c(65L, 65L, 65L, 65L, 38L, 38L), time = c(0L, 
    392L, 756L, 1125L, 0L, 351L), BMI = c(23.301094832264, 22.4392735165502, 
    21.9604838967091, 22.6627066115703, 39.3535698314, 39.7355371900827
    ), Status = c(0L, 0L, 0L, 0L, 0L, 0L)), .Names = c("Enum", "Sex", 
    "Left_R", "Right_R", "risk", "Chol_val", "HbA1c_val", "eGFR_val", 
    "Duration", "Age", "time", "BMI", "Status"), row.names = c(NA, 
    6L), class = "data.frame")

Can you provide a reproducible example of data. Using dput(head(your_dataframe)) is a good way — Jonno Bourne, Oct 17 '16 at 09:33
Even with the data, "line up by" is still pretty vague. A good example will also explain and illustrate desired output. See guidance here: http://stackoverflow.com/a/28481250/ — Frank, Oct 17 '16 at 14:48

score 0 · Answer 1 · answered Oct 17 '16 at 14:42

If I understand the question correctly you wish to order the patiants by the maximum time they gave a measurement

library(dplyr)
test <- df %>% group_by(Enum) %>% mutate(maxtime = max(time)) %>% 
ungroup %>% arrange(maxtime, Enum) %>% select(-maxtime)

if you wish to order them from largest time to smallest time use arrange(desc(maxtime), Enum).

How to Line up all patients by their final time in R

1 Answers1