my work also requires regular use of SPSS which I have been skipping on my own loss.
I had raised the issue about it in the NVDAcon Asia which happened around 2015-16 where Joseph Lee was very elaborate in answering the question but the technicalities could not go into my head :) (I am not a wise tech user). Anyway, the conclusion was that SPSS was not accessible with NVDA and changes were to be made by both IBM (the developer of SPSS) and NVDA to make it usable with a screen reader.
Since then, I have been waiting for the development.
Dr. Sharad Koirala
Department of Community Medicine
Gandaki Medical College, Pokhara, Nepal