Measuring amount of symptom change in the diagnosis of premenstrual syndrome.

Agreement was computed between 3 methods of measuring prospectively rated symptom change in premenstrual syndrome. Ss were 87 women, ranging in age from 21 to 50 years (M=34,8), who visited a premenstrual syndrome clinic seeking treatment for their symptoms. All Ss made daily symptom ratings for 2 menstrual cycles. The rating were analyzed according to 3 methods: percentage change from post- to premenstrual phases, computed with reference to an individual's minimum and maximum ratings; and the analysis of trend by time series analysis