The results from a sleep test can be complicated and technical, but there are a few important values and recommendations to look for.
Hundreds of thousands of sleep tests are performed each year, many done in the home and some in a sleep lab. After each test, the data is analyzed by a technician and then reviewed by a sleep physician specialist to make a diagnosis and recommend treatment based on the results.
The physician’s report is called an interpretation — which is often combined with a technical report of the data that includes recording times, event counts, and average measurements of each channel. Both parts of the report will include medical terms and technical analysis, which can be challenging to decipher.
This article will explain each section of the report, highlight and explain key numbers to look for, and describe what to expect from the results.
The physician’s review of the test will have 3 key sections: Diagnosis, Impressions, and Recommendations. There may be one or more diagnoses from the data collected, and occasionally none. The impressions give more detail about the test and diagnosis, and the recommendations are suggested treatments, lifestyle changes, and medical follow up that should be considered based on the diagnosis. If you have a copy of your sleep test results, find those sections and continue reading to understand each.
The Most Important Data Value on a Sleep Test Report
However, before going any further, it is important to understand the most important number on your sleep report: Apnea Hypopnea Index (AHI). The sleep test measures airflow, and when there is a pause in breathing of at least 10 seconds, it is considered either an apnea or hypopnea. The difference is a complete stop of airflow (apnea) or significantly reduced airflow (hypopnea), but both cause a disturbance in sleep. The sleep test software then calculates an Index of the events, which is the average number of events per hour of sleep.
In math terms:
AHI = (# apneas + # hypopneas) / Hours of Sleep
If the AHI is 5 or higher, then the patient is considered to have sleep apnea and there will be a diagnosis of sleep apnea. The AHI is also used to determine the severity of sleep apnea, which will be in the Impressions section of the report. AHI over 15 is moderate, and AHI over 30 in severe, but it is often much higher.
Diagnosis Section of a Sleep Test
The report’s Diagnosis section is usually just a list of medical conditions that are being diagnosed from the test data, which is often a form of sleep apnea — but there could also diagnosis-related oxygen saturation or heart rate.
The most common diagnosis from a Home Sleep Test is obstructive sleep apnea (OSA), which means the majority of apneas and hypopnea occurred as a result of the airway closing. The patient stops breathing despite effort from the diaphragm muscle to attempt breathing. Learn more about OSA.
Another possible diagnosis is Central Sleep Apnea (CSA) which is less common but just as dangerous. Central apneas occur when there is no attempt to breathe, and is often associated with other medical conditions such as COPD or heart failure. Learn more about CSA
Sleep tests may list a diagnosis for nocturnal hypoxemia which means there is significant time with low oxygen levels in the blood. Sleep tests also monitor heart rate and there could be a diagnosis of tachycardia or bradycardia, meaning that the heart rate was abnormally high or low, respectively. All of the diagnoses will come with associated recommendations.
You will usually see a code next to each diagnosis starting with a letter follow by a number. For example, obstructive sleep apnea will be followed by G47.33. It is the ICD-10 diagnosis code for the medical condition. ICD-10 codes are a set of national standards used by medical providers and insurance companies to document conditions. Your insurance company may ask for a diagnosis code, and medical equipment companies that provide treatment will definitely need the code.
Impressions from the Physician
This is the section where the physician will give the severity of the condition, such as mild, moderate, or severe sleep apnea. It may describe the quality and quantity of the data recorded or when events occurred. The physician may add details on how and why the diagnosis was made.
Recommendations for Treating Sleep Disorders
Based on diagnosis and medical history, the physician will give a list of recommendations. The most common recommendation for sleep apnea is CPAP. This stands for continuous positive air pressure and works by using air pressure to act as a splint to keep the airway open. You can think of it like a hose. When water is turned on, a hose stays open and taught, but when there is no water in a hose, it is easy to kink and close off. The air flowing through the airway keeps it open the same way, but since it is a low pressure so you can still inhale and exhale.
CPAP is the most effective treatment for sleep apnea, especially for severe OSA. The recommendation may specify AutoCPAP, which is just a type of CPAP device that will automatically adjust the air pressure to a level needed to eliminate apneas. It is easier to get used to, and it prevents you from having to go into a sleep lab to determine the correct pressure setting.
If the sleep apnea is severe or categorized as central instead of obstructive, there may be a recommendation for a follow-up sleep study in a sleep lab to monitor additional channels and try different CPAP settings to determine the best pressure mode and level.
If the sleep apnea is mild and obstructive, then there may be several treatment recommendations listed, including oral appliance, airway surgery, airway stimulation, or even a simple positional pillow. Many people prefer the size and comfort of an oral appliance. It works by holding the jaw, or mandible, slightly forward to keep the tongue from falling into the airway. Learn more about it and all of these treatment options.
Recommendations may include the statement “could be considered”, but that doesn’t mean treatment isn’t recommended — it just means it’s one of a couple options or could be done in conjunction with other treatment.
The important thing is to start treatment so that you sleep well and reduce your risk of other medical conditions like high blood pressure and diabetes. Try it, give it chance, and maybe try an alternative, but don’t give up. You deserve a good night’s sleep!