Question 1 :
data_MACE = read_csv2("./Data/data_MACE.csv")
Using ',' as decimal and '.' as grouping mark. Use read_delim() for more control.
Parsed with column specification:
cols(
prior_OAD = col_character(),
metformine_treat = col_character(),
MACE = col_character()
)
glimpse(data_MACE)
Observations: 11,000
Variables: 3
$ prior_OAD <chr> "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "...
$ metformine_treat <chr> "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "...
$ MACE <chr> "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "yes", "...
- Estimer la probabilité d’avoir un
MACE
parmi les personnes traitées avec la metformine et parmi ceux traités par sitagliptine.
Correction
data_MACE %>% count(MACE) %>%
mutate(freq = n / sum(n))
Correction
data_MACE %>% count(metformine_treat) %>% mutate(freq = n / sum(n))
Correction
data_MACE %>% group_by(metformine_treat,MACE) %>% summarize(n= n()) %>% mutate(freq = n / sum(n))
print(c("proba of MACE among metformine yes",350/4000))
[1] "proba of MACE among metformine yes" "0.0875"
print(c("proba of MACE among metformine no",round(500/7000,digits = 2)))
[1] "proba of MACE among metformine no" "0.07"
Question 3
- Appliquer la méthode de stratification pour calculer la probabilité d’avoir un MACE si tout le monde avait reçu de la metformine, même chose si personne n’en avait reçu.
Correction
data_freq = data_MACE %>% group_by(metformine_treat,prior_OAD,MACE) %>% summarise(n = n()) %>%
mutate(freq = n / sum(n))
data_freq
Correction
proba_prior_OAD = data_MACE %>% group_by(prior_OAD) %>% summarise(n = n()) %>%
mutate(freq = n / sum(n))
proba_prior_OAD
Correction
expected_proba_MACE_alltreated = filter(data_freq,metformine_treat == "yes",prior_OAD=="yes",MACE=="yes")$freq * proba_prior_OAD$freq[2] +
filter(data_freq,metformine_treat == "yes",prior_OAD=="no",MACE=="yes")$freq * proba_prior_OAD$freq[1]
expected_proba_MACE_alltreated
[1] 0.07727273
Correction
expected_proba_MACE_notreated = filter(data_freq,metformine_treat == "no",prior_OAD=="yes",MACE=="yes")$freq * proba_prior_OAD$freq[2] +
filter(data_freq,metformine_treat == "no",prior_OAD=="no",MACE=="yes")$freq * proba_prior_OAD$freq[1]
expected_proba_MACE_notreated
- Puis l’estimer l’effect causal de du traitement (metformine ou non) sur le risque de MACE.
Correction
expected_proba_MACE_alltreated - expected_proba_MACE_notreated