Can we conduct medical exams before we make offers to out-of-state applicants?

Q. My company would like to institute a policy of conducting medical examinations on out-of-state applicants when workers interview here for jobs. This would reduce the number of trips an applicant would have to make before beginning employment with our company. The test results would be sealed (so the information cannot be relied upon in making job offers) and would be reviewed only if we offered, and the applicant accepted, a conditional offer of employment. Would such an arrangement violate the ADA? ...