This is a charge for the amount of mileage an ambulance service or other transportation service will bill for while transporting a patient. https://coder.aapc.com/hcpcs-codes/A0425
Thanks @jenniferduryea. I sensed this was a billing artifact. Appreciate your help confirming this hypothesis.
My curiosity is if anyone else encountered this covariate in the context of say a PLE or PLP study and had any examples of tactically using this variable. It doesn’t strike me as having a lot of clinical value other than we know the individual had to move locations of care and perhaps it’s a proxy for acute patients in claims data.