We applied data reduction methods to summarize the data.
Principal component analysis (PCA) was used to determine which
gastrointestinal disorders (dependent variable) were treated with
particular combinations of plant life forms, plant parts, or preparation
modes (independent variables) (Lepš and Šmilauer,
2003). PCA was also used to verify which types of gastrointestinal disorders were treated with the same plant families. PCA was
carried out using Canoco 5.01