when do you use the term incidence rate ratio when is ppgsi used define incidence rate ratio what is the correlation of the incidence rate ratio what is the difference between pgsi and incidence rate ratio definition of incidence ratios what is a incidence ratio why use the term glm incidence ratio what is the incidence rate ratio does interval ratio work what is pgsi score what is pgsi what's the incident rate ratio definition of the term incidence rate ratio what is the definition of incidence rate ratios what is the incidence rate ratio used for when to use incidence rate ratio what's the difference between a psychological score and incidence ratio? what is the difference between psy and correlation what is the impact ratio for psychometric testing