Assessment of menstrual cycle symptoms by trend analysis.

The physical, psychological, and behavioral changes associated with the menstrual cycle can be assessed statistically by time series analysis. One such method, Trigg's technique for trends, has been adapted for the study of prospective symptom ratings used in evaluation of the premenstrual syndrome. Such analysis provides both qualitative and quantitative information concerning menstrual cycle symptomatology. The pattern of symptoms, as denoted by Trigg's tracking signal, can be identified. The premenstrual syndrome can be defined mathematically in terms of significant symptom trends at specified times in the menstrual cycle. The overall severity of symptoms at any point in the cycle can be gauged by the exponentially smoothed average symptom ratings. A derived statistic, the menstrual cycle ratio, is proposed as a global index of menstrual cycle morbidity which can be easily standardized to allow for comparability of research reports.