We read with great interest the article by Luther et al on how the national reduction in cerebral arteriovenous malformation (AVM) treatment correlated with increased rupture incidence.1 This study analyzed 154 297 patients with AVMs via the National Inpatient Sample (NIS) from 2003 to 2017.1 The study evaluated the influence of contemporary AVM management on AVM rupture patterns in the US, with a particular interest in trends before and after 2014, coinciding with publication of the A Randomized trial of Unruptured Brain Arteriovenous Malformations (ARUBA) trial.1 2 Luther et al used the codes from the International Classification of Diseases (ICD), ninth and 10th revisions, to identify AVMs and their associated sequelae.1 The authors concluded that after 2014, “the likelihood of intervention for unruptured AVMs decreased while the incidence of ruptured AVMs increased.”1

We applaud the authors for a thorough analysis of this important topic. Their study went beyond the previous single center series of ARUBA eligible patients that have refuted ARUBA’s conclusions and demonstrated the real world consequences of its publication.3 4 The NIS stands as an invaluable resource, encompassing a vast array of patient records and providing a robust foundation for conducting large scale, population based studies. Its extensive scope and wealth of data allow for a deeper understanding of epidemiological trends and the exploration of vital healthcare related questions. Furthermore, the research pursued by Luther and colleagues showcased a novel approach that investigated the influence of contemporary AVM management on AVM rupture patterns. However, we have a few inquiries regarding the study methodology.

We raise concerns specific to the coding scheme used by …