以 R 数据框中的其他列为条件创建新的二进制列

Question

Trying to input a scoring system into R so I can validate it for my data.

I want to assign a score to set binary outcomes.

In this case if my patient has heamaglobin (Hb) <8 (yes 1 or no 0). I want to assign a score of 5 points when haemoglobin (Hb<8) = 1.

| Patient number | Hb<8 |
|----------------|------|
| 1 | 0 |
| 2 | 1 |
| 3 | 0 |
| 4 | 1 |

How do I create a new coloumn that would read either 0 or 5 depending on the factor in the Hb coloumn?

Many thanks

Answer 1

Try this:

df <- data.frame(patient = c(1, 2, 3, 4),
                 hb_smaller_8 = c(0, 1, 0, 1))

df <- df %>% mutate(score = ifelse(hb_smaller_8 == 1, 5, 0))

> df
  patient hb_smaller_8 score
1       1            0    NA
2       2            1     5
3       3            0    NA
4       4            1     5

Answer 2

A simple ifelse statement in base R will do:

df$score <- ifelse(df$hb_smaller_8 == 1, 5, NA)

df
  patient hb_smaller_8 score
1       1            0    NA
2       2            1     5
3       3            0    NA
4       4            1     5