Impairment is when a physical disability prevents a doctor from practicing medicine with skill and dedication. Impairment also includes substance abuse. If you are abusing a substance you must admit it to yourself and proactively obtain treatment.
OPMC will help a physician who is honestly attempting to overcome an addiction but will not tolerate someone who is lying about the situation. Clearly, physicians who are addicted are a danger to their patients and OPMC is in the business of protecting patients.
If your impairment is a physical one, for instance you sustained a stroke, you must be honest with yourself. Are you really able to care for patients?
If the stroke has left you somewhat physically impairment but mentally you are undamaged, you might be well served to have your treating neurologist attend the interview and discuss your situation. As the treating physician, his opinions will carry a good deal of weight.