Agree with the other posters. I think it is important to have your PS and secondaries flow together, i.e., in your PS you probably discussed why medicine and perhaps why DO. In your secondaries you should build on that to include more of why DO and why school X. I reviewed each school's mission statements and used that to blend with my own values in my secondaries. Having a cohesive story that flows from why medicine-->why school X will make the interviews go smoother - at least it helped me. I was asked at every interview why medicine, why DO, why our school.
Good luck!