Cochran–Armitage trend test
Test a linear trend in proportions across ordered groups.
When to use it
Use Cochran–Armitage when the outcome is binary and the groups have an order. It is the z-test cousin of the Mantel–Haenszel trend test.
Assumptions
The group column must sort into the intended order. The outcome has two levels.
Running it in Tensr
Options
Prop
Type
Reading the output
The same dose groups against a response that rises from low to high.
Cochran–Armitage trend test: response by dose (decreasing trend). The primary result is significant (p = < .001). This is large enough, in this sample, to treat the comparison this page is about as a real association rather than noise. Metrics: Z = -29.811; p (two-tailed) = < .001; p (one-tailed) = > .999; Trend = decreasing.
Reporting (APA 7)
Cochran–Armitage trend test: response by dose (decreasing trend). This result is significant (p = < .001). The effect is moderate, so report its size with the p-value.
Coming from SPSS
Analyze → Correlate → Cochran-Armitage Trend.