Can I suggest that this kind of data is not normally present in OSM - for example school and medical catchment area boundaries due to the fact they are not published publicly and therefore are not verifiable by other contributors if they change or are removed. Additionally, the tag landuse=residential was incorrect. Can I suggest that you create this area as an overlay in another service for example https://umap.openstreetmap.fr/en/, rather than importing this data directly into OSM? In my opinion as this catchment area is for internal use, it's not appropriate for being in OSM. Umap will provide the same functionality, if not better for what you are trying to do in providing information for your patients.