This abbreviation stands for “obstructive sleep apnea hypopnea syndrome.” This term may appear on a prescription, but it does not clearly indicate the doctor’s expectations or the test to be performed to obtain a diagnosis of sleep apnea. A simplified test (e.g. cardiorespiratory polygraph) can be performed at home, while a comprehensive test (e.g. complete polysomnography) can be performed in the laboratory. Our client relations centre can be contacted to validate your prescription and, if necessary, a clarification can be made with your doctor.