Correctly place geom_text labels in forest plot with "fill" parameter in ggplot2

Question

I want to create annotated publication-ready forest plots comparing different models. How do I ensure that the labels are placed above and tight against the corresponding error bars and do not overlap?

I've also asked the RStudio community for help on March 9, 2022. Here is a link to the original post.

Thank you for your help!

Here is what I tried:

library(tidyverse)
#> Warning: package 'tibble' was built under R version 4.1.2
#> Warning: package 'tidyr' was built under R version 4.1.2
#> Warning: package 'readr' was built under R version 4.1.2
#> Warning: package 'dplyr' was built under R version 4.1.2
library(knitr)
#> Warning: package 'knitr' was built under R version 4.1.2
data <- tibble::tribble(
  ~term, ~n_obs,   ~estimate,   ~conf.low,  ~conf.high,            ~ci,    ~p.value,  ~group,
    "A",   101L,        0.62, 0.497390282, 0.797429694, "0.50 to 0.80", 0.000123131,   "One",
    "A",    65L,        0.57, 0.468908017, 0.693458768, "0.47 to 0.69", 1.83138e-08,   "Two",
    "A",    36L,        0.81, 0.623804568, 1.064787867, "0.62 to 1.06", 0.133680272, "Three",
    "B",    26L,        0.87, 0.665400224,   1.1489204, "0.67 to 1.15", 0.335220534,   "One",
    "B",    16L,        1.02, 0.755403541, 1.388386542, "0.76 to 1.39", 0.878076678,   "Two",
    "B",    10L,        0.29, 0.091804704, 0.978289216, "0.09 to 0.98", 0.045898245, "Three",
    "C",   143L,        0.90, 0.749027775, 1.089930323, "0.75 to 1.09", 0.289131987,   "One",
    "C",    82L,        1.02,  0.82229374, 1.286815562, "0.82 to 1.29", 0.804649191,   "Two",
    "C",    61L,        0.61, 0.359730119, 1.036462037, "0.36 to 1.04",  0.06765433, "Three"
  )
data %>% kable()

term	n_obs	estimate	conf.low	conf.high	ci	p.value	group
A	101	0.62	0.4973903	0.7974297	0.50 to 0.80	0.0001231	One
A	65	0.57	0.4689080	0.6934588	0.47 to 0.69	0.0000000	Two
A	36	0.81	0.6238046	1.0647879	0.62 to 1.06	0.1336803	Three
B	26	0.87	0.6654002	1.1489204	0.67 to 1.15	0.3352205	One
B	16	1.02	0.7554035	1.3883865	0.76 to 1.39	0.8780767	Two
B	10	0.29	0.0918047	0.9782892	0.09 to 0.98	0.0458982	Three
C	143	0.90	0.7490278	1.0899303	0.75 to 1.09	0.2891320	One
C	82	1.02	0.8222937	1.2868156	0.82 to 1.29	0.8046492	Two
C	61	0.61	0.3597301	1.0364620	0.36 to 1.04	0.0676543	Three

data %>% rowwise() %>%
  ## plot with variable on the y axis and estimate (OR) on the x axis
  ggplot(aes(x = estimate, y = term, color = group), alpha = .7, width = .7) +

  ## show the estimate as a point
  geom_point(position = position_dodge(.9), size = 1.5) +
        
  
  ## add in an error bar for the confidence intervals
  geom_errorbar(aes(xmin = conf.low, xmax = conf.high), position = position_dodge(.9), size = 1) +
        
        ## add in labels     
  geom_text(aes( label = paste0(estimate, " (", ci, ") n = ", n_obs), x = estimate, y = term),color = "black", position = position_dodge(.9), show.legend = FALSE, check_overlap = FALSE) +

  ggplot2::theme_bw() +
  scale_colour_grey() +

  ## show where OR = 1 is for reference as a dashed line
  geom_vline(xintercept = 1, linetype = "dashed") +
  ylab("") +
  xlab("") +
  theme(legend.position = "top")

^{Created on 2022-03-19 by the reprex package (v2.0.1)}

Answer 1

You need to add a grouping variable to the text layer, since you remove its dodging variable by specifying color = 'black' outside aes.

Also, you can use vjust to move the text above the bars:

data %>% rowwise() %>%
  ggplot(aes(x = estimate, y = term, color = group), alpha = .7, width = .7) +
  geom_point(position = position_dodge(.9), size = 1.5) +
  geom_errorbar(aes(xmin = conf.low, xmax = conf.high), 
                position = position_dodge(.9), size = 1) +  
  geom_text(aes( label = paste0(estimate, " (", ci, ") n = ", n_obs), 
                 x = estimate, y = term, group = group), color = "black", 
            position = position_dodge(0.9), vjust = -0.4,
            show.legend = FALSE, check_overlap = FALSE) +
  ggplot2::theme_bw() +
  scale_colour_grey() +
  geom_vline(xintercept = 1, linetype = "dashed") +
  ylab("") +
  xlab("") +
  theme(legend.position = "top")