[Morbidity Compression in Stroke: Longitudinal Analyses on Changes in the Incidence of Stroke]

According to Fries, morbidity compression occurs if age at onset of disease/disability and age at death increase. Morbidity compression is also present if disease/disability rates decrease to the same or to a larger extent than standardized death rates. In all cases, healthy lifetime is gained. Not many studies on morbidity compression are available, and only a small number of them refer to specific diseases. Stroke is used as an example for examining whether morbidity compression has occurred over an observation period of 9 years.

The study was based on pseudonymized data of a statutory health insurance covering 2006-2014 with 2 million insured per year. Analyses were performed for all types of stroke, separately for cerebral infarction, and for hemorrhages (ICD 10: I60-I62). Calculations were performed by means of survival analyses and with multiple regression.

In women and in men, rates decreased only for hemorrhagic strokes, while changes of onset age were difficult to interpret. Standardized death rates dropped only in males.

Evidence in favor of morbidity compression was found only for decreasing rates of hemorrhagic strokes. It has, however, to be kept in mind that the findings refer to a single disease occurring relatively late in the life course. Comprehensive assessments of morbidity compression are only possible taking into consideration a broader spectrum of diseases.