Performs chi-squared test for trend in proportion. This test is also known as Cochran-Armitage trend test.
Wrappers around the R base function prop.trend.test() but
returns a data frame for easy data visualization.
prop_trend_test(xtab, score = NULL)a cross-tabulation (or contingency table) with two columns and multiple rows (rx2 design). The columns give the counts of successes and failures respectively.
group score. If NULL, the default is group number.
return a data frame with some the following columns:
n: the number of participants.
statistic: the value of
Chi-squared trend test statistic.
df: the degrees of
freedom.
p: p-value.
method: the used statistical test.
p.signif: the significance level of p-values and adjusted p-values,
respectively.
The returned object has an attribute called args, which is a list holding the test arguments.
# Proportion of renal stone (calculi) across age
#%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
# Data
xtab <- as.table(rbind(
c(384, 536, 335),
c(951, 869, 438)
))
dimnames(xtab) <- list(
stone = c("yes", "no"),
age = c("30-39", "40-49", "50-59")
)
xtab
#> age
#> stone 30-39 40-49 50-59
#> yes 384 536 335
#> no 951 869 438
# Compare the proportion of survived between groups
prop_trend_test(xtab)
#> # A tibble: 1 × 6
#> n statistic p p.signif df method
#> * <dbl> <dbl> <dbl> <chr> <dbl> <chr>
#> 1 3513 49.7 1.78e-12 **** 1 Chi-square trend test