Measures of cholesterol concentration in 72 participants treated with three different drugs. The aim is to examine the potential of new class of drugs in lowering the cholesterol concentration and consequently reducing heart attack.
The participants include 36 males and 36 females. Males and females were further (equally) subdivided into whether they were at low or high risk of heart attack.
This data set is suited for three way Anova test.
For a worked tutorial on this analysis, see the Datanovia lesson “Three-Way ANOVA in R: Three Factors and Their Interaction” (https://www.datanovia.com/learn/biostatistics/anova/three-way-anova-in-r).
data("heartattack")A data frame with 72 rows and 5 columns (stored as a tibble).
the participant's gender, "male" or "female".
the participant's heart attack risk, "high" or "low".
the drug received, "A", "B" or "C".
the blood cholesterol concentration.
participant identifier (1 to 72).
A simulated dataset for teaching three-way ANOVA.
headache, the companion three-way ANOVA data set.
Datanovia tutorial:
Three-Way ANOVA in R: Three Factors and Their Interaction.
data(heartattack)
head(heartattack)
#> # A tibble: 6 × 5
#> gender risk drug cholesterol id
#> <fct> <fct> <fct> <dbl> <int>
#> 1 male low A 5.24 1
#> 2 male low A 5.08 2
#> 3 male low A 4.68 3
#> 4 male low A 5.36 4
#> 5 male low A 4.96 5
#> 6 male low A 4.83 6
# Three-way ANOVA of the cholesterol concentration
summary(aov(cholesterol ~ gender * risk * drug, data = heartattack))
#> Df Sum Sq Mean Sq F value Pr(>F)
#> gender 1 1.367 1.367 16.196 0.000163 ***
#> risk 1 7.825 7.825 92.699 8.8e-14 ***
#> drug 2 1.235 0.618 7.318 0.001433 **
#> gender:risk 1 0.012 0.012 0.141 0.708487
#> gender:drug 2 0.564 0.282 3.338 0.042200 *
#> risk:drug 2 0.120 0.060 0.713 0.494221
#> gender:risk:drug 2 1.250 0.625 7.406 0.001334 **
#> Residuals 60 5.065 0.084
#> ---
#> Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1