I have data on repeated measurements of 8 patients, each with varying amount of repeated measurements on the same variables. The measured variables are sex, blood pressure (sys_bp), and how many CT scans a person underwent:
library(dplyr)
library(magrittr)
questiondata <- structure(list(id = c(2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4,
4, 7, 7, 8, 8, 8, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 20,
20, 20), time = structure(c(1L, 2L, 3L, 4L, 1L, 2L, 3L, 4L, 5L,
1L, 2L, 3L, 4L, 5L, 1L, 6L, 1L, 2L, 5L, 1L, 2L, 3L, 4L, 5L, 1L,
2L, 3L, 4L, 5L, 1L, 2L, 4L), .Label = c("T0", "T1M0", "T1M6",
"T1M12", "T2M0", "FU1"), class = "factor"), sys_bp = c(116, 125.8,
NA, NA, NA, 113.2, NA, NA, NA, NA, 146, NA, NA, NA, NA, NA, NA,
125, NA, NA, 164.5, NA, NA, NA, NA, 150.5, NA, NA, NA, NA, 158,
NA), sex = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L,
2L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L,
2L, 2L, 2L, 1L, 1L, 1L), .Label = c("female", "male"), class = "factor"),
ct_amount = c(4L, 4L, 4L, 4L, 5L, 5L, 5L, 5L, 5L, 5L, 5L,
5L, 5L, 5L, 2L, 2L, 3L, 3L, 3L, 5L, 5L, 5L, 5L, 5L, 5L, 5L,
5L, 5L, 5L, 3L, 3L, 3L)), row.names = c(NA, -32L), class = c("tbl_df",
"tbl", "data.frame"))
questiondata
id time sys_bp sex ct_amount
<dbl> <fct> <dbl> <fct> <int>
1 2 T0 116 female 4
2 2 T1M0 126. female 4
3 2 T1M6 NA female 4
4 2 T1M12 NA female 4
5 3 T0 NA female 5
6 3 T1M0 113. female 5
7 3 T1M6 NA female 5
8 3 T1M12 NA female 5
9 3 T2M0 NA female 5
10 4 T0 NA male 5
11 4 T1M0 146 male 5
12 4 T1M6 NA male 5
13 4 T1M12 NA male 5
14 4 T2M0 NA male 5
15 7 T0 NA female 2
16 7 FU1 NA female 2
17 8 T0 NA female 3
18 8 T1M0 125 female 3
19 8 T2M0 NA female 3
20 13 T0 NA female 5
21 13 T1M0 164. female 5
22 13 T1M6 NA female 5
23 13 T1M12 NA female 5
24 13 T2M0 NA female 5
25 14 T0 NA male 5
26 14 T1M0 150. male 5
27 14 T1M6 NA male 5
28 14 T1M12 NA male 5
29 14 T2M0 NA male 5
30 20 T0 NA female 3
31 20 T1M0 158 female 3
32 20 T1M12 NA female 3
I am trying to count the number of persons that (1) is male/female (2) has 1/2/3/4/5 CT scans.
So the output would be that there are (1) 6 females and 2 males, and (2) 1 person with 2 CTs, 2 persons with 3 CTs, 1 person with 4 CTs and 4 persons with 5 CTs.
I've tried many combinations of group_by and summarise and count, but can't seem to get it right. Any help?
You can first keep only the unique rows for each id. Then use count to get the output.
library(dplyr)
unique_data <- questiondata %>% distinct(id, .keep_all = TRUE)
unique_data %>% count(sex)
# A tibble: 2 x 2
# sex n
# <fct> <int>
#1 female 6
#2 male 2
unique_data %>% count(ct_amount)
# A tibble: 4 x 2
# ct_amount n
# <int> <int>
#1 2 1
#2 3 2
#3 4 1
#4 5 4