Add column with N

Source: R/add_n.R

For each variable in a tbl_summary table, the add_n function adds a column with the total number of non-missing (or missing) observations

# S3 method for class 'tbl_summary'
add_n(
  x,
  statistic = "{N_nonmiss}",
  col_label = "**N**",
  footnote = FALSE,
  last = FALSE,
  ...
)

# S3 method for class 'tbl_svysummary'
add_n(
  x,
  statistic = "{N_nonmiss}",
  col_label = "**N**",
  footnote = FALSE,
  last = FALSE,
  ...
)

# S3 method for class 'tbl_likert'
add_n(
  x,
  statistic = "{N_nonmiss}",
  col_label = "**N**",
  footnote = FALSE,
  last = FALSE,
  ...
)

Arguments

x

(tbl_summary)
Object with class 'tbl_summary' created with tbl_summary() function.

statistic

(string)
String indicating the statistic to report. Default is the number of non-missing observation for each variable, statistic = "{N_nonmiss}". All statistics available to report include:

  • "{N_obs}" total number of observations,

  • "{N_nonmiss}" number of non-missing observations,

  • "{N_miss}" number of missing observations,

  • "{p_nonmiss}" percent non-missing data,

  • "{p_miss}" percent missing data

The argument uses glue::glue() syntax and multiple statistics may be reported, e.g. statistic = "{N_nonmiss} / {N_obs} ({p_nonmiss}%)"

col_label

(string)
String indicating the column label. Default is "**N**"

footnote

(scalar logical)
Logical argument indicating whether to print a footnote clarifying the statistics presented. Default is FALSE

last

(scalar logical)
Logical indicator to include N column last in table. Default is FALSE, which will display N column first.

...

These dots are for future extensions and must be empty.

Value

A table of class c('tbl_summary', 'gtsummary')

Author

Daniel D. Sjoberg

Examples

# Example 1 ----------------------------------
trial |>
  tbl_summary(by = trt, include = c(trt, age, grade, response)) |>
  add_n()



  
Characteristic
      N
      Drug A

N = 981		
      Drug B

N = 1021		
    
Age
189
46 (37, 60)
48 (39, 56)
    Unknown


7
4
Grade
200



    I


35 (36%)
33 (32%)
    II


32 (33%)
36 (35%)
    III


31 (32%)
33 (32%)
Tumor Response
193
28 (29%)
33 (34%)
    Unknown


3
4
1 Median (Q1, Q3); n (%)
    

# Example 2 ----------------------------------
survey::svydesign(~1, data = as.data.frame(Titanic), weights = ~Freq) |>
  tbl_svysummary(by = Survived, percent = "row", include = c(Class, Age)) |>
  add_n()



  
Characteristic
      N
      No

N = 1,4901		
      Yes

N = 7111		
    
Class
2,201



    1st


122 (38%)
203 (62%)
    2nd


167 (59%)
118 (41%)
    3rd


528 (75%)
178 (25%)
    Crew


673 (76%)
212 (24%)
Age
2,201



    Child


52 (48%)
57 (52%)
    Adult


1,438 (69%)
654 (31%)
1 n (%)