There are 5 DO/PhD programs that offer biomedical based PhDs, MSUCOM, OUCOM, OSUCHS, and UNTHSC TCOM. When I was looking into doing a DO after my PhD I went through these schools science departments to see if I could find a practicing DO/PhD in a academic position. I primarily focused on MSU and did find two such persons, one primarily clinical but the other was participating in molecular biology research and working on the clinical side. I'll post the contact after I look it up again. I talked to both of them and they gave great advice. Primarily you are viewed the same and treated as such. Basically the PhD world sees your PhD and the clinical world your DO.
As for stats, the websites are pretty good for this info. If you have more questions thenI would try calling the program admissions office.