We thank the authors of correspondence for the advice and for suggesting further analyses. In addition to presenting the incidence and prevalence of stroke events, the aim of the study was to analyze the frequency of recurrence and mortality after a stroke incident (1). We agree with the authors that, in general, even more detailed and stratified analyses are possible. In addition to intensive care stays (as mentioned), taking into consideration the effects of comorbidities would also be relevant. We welcome the advice and will take it into account in future analyses. In particular, comparing the quality of care and the clinical outcome over time seems particularly interesting. There are various limitations associated with the use of routine data, which we discussed in detail. One is the definition used for recurrence, which is based on international studies but could lead to an underestimation of the frequency of recurrence. Further, no information on stroke severity or other clinical information is available in the billing data.
As part of a supplementary analysis, treatment in a stroke unit was added to the regression model for recurrence as outcome. This revealed that stroke unit treatment did not significantly affect the risk of recurrence (hazard ratio: 0.966; p = 0.439). Data also showed that the different types of stroke were treated with varying frequency in a stroke unit. While more than half (54.8%) of all patients with ischemic stroke (I63) were treated in a stroke unit, the proportion was significantly lower for those with hemorrhagic strokes (I60: 10.8%; I61: 34.4%; I62: 7.8%) or unspecified strokes (I64: 18.6%).
On behalf of the authors
Dr. PH Jona T. Stahmeyer
AOK Niedersachsen, Hannover
Conflict of interest statement
The author declares that no conflict of interest exists.
|1.||Stahmeyer JT, Stubenrauch S, Geyer S, Weissenborn K, Eberhard S: The frequency and timing of recurrent stroke—an analysis of routine health insurance data. Dtsch Arztebl Int 2019; 116: 711–7 VOLLTEXT|