While their existence is considered proven, there is some doubt as to whether they were as widespread as was once thought, as many were identified only according to the layout of building remains, and not by means of surviving records or finds of medical tools.
Ndërsa ekzistenca e tyre konsiderohet e provuar, nuk ka dyshim mbi atë se nëse ata ishin si të gjerë siç ishte menduar dikur, si shumë janë identifikuar vetëm sipas shtrirjes e ndërtimit të mbetet, dhe jo me anë të mbijetuar regjistrimet ose gjen i mjeteve mjekësore.