The Washington Post piece I linked to (Permanent URL: <http://web.archive.org/web/20180326154159/https://www.washingtonpost.com/blogs/post-partisan/wp/2018/03/2

The Washington Post piece I linked to (Permanent URL: <http://web.archive.org/web/20180326154159/https://www.washingtonpost.com/blogs/post-partisan/wp/2018/03/26/the-truth-about-medical-bankruptcies/?utm_term=.60031f592030 http://web.archive.org/web/20180326154159/https://www.washin...> discusses the Himmelstein article the letter you cited cites. As arpinum said, Himmelstein et al. conflate any debt that includes medical bills at time of bankruptcy with "medical bills caused bankruptcy".