Chi-squared approximation may be incorrect Please I need your help. I am trying to run this data using R but it throws an error message 'Chi-squared approximation may be incorrect.' Is something wrong with my data?
> Hypotension_tab1 <- table(VR1$'Hypotension during treatment?',VR1$'Maximum tolerated dose of Vericiguat (mg)')
> Hypotension_tab1
     
      2.5 5 7.5 10
  No    5 4   1  1
  Yes   1 4   0  1

> chisq.test(Hypotension_tab1)

    Pearson's Chi-squared test

data:  Hypotension_tab1
X-squared = 2.404, df = 3, p-value = 0.4929


Warning message:
In chisq.test(Hypotension_tab1) :
Chi-squared approximation may be incorrect


First it is not an error but a warning.
Second, as a general rule the count of individuals per bin should be greater than 5 for the chi sq test. Most of your bins have only 0 or 1 in them. So either add multiple bins together to exceed 5 or use another test such as the Fisher's Exact test: fisher.test().
