St. Francis clearances

Hi, I was wondering if everyone used the doctors that St. Francis listed. Dr. Dettwyler (sp?) or a social worker Mr Blane Morris for the psychologist appt. Would it be better to use their doctors only because they are familiar with what needs sent to CHRIAS or what. If not can someone recommend a doctor close by Christiana area? Also, how long are the classes at St. Francis take and what are they? I just need to make sure my cardio clearance and the sleep study test dont get outdated. My cardio I went for on FEb 28th but he wants to do a stress test since my Primary doctor wants it and the sleep study is on March 24th along with the cardio clearance appt for the stress test results Any help would be appreciated. Thanks, Sharon