A home sleep study which is also called a Home Sleep Test (HST) is an assessment that takes place in your home at night whilst you are asleep.
An HST is only one form of sleep study that is available. Other sleep studies happen in specialist facilities called sleep labs. These tend to be labelled as an “in-lab sleep study”.
An HST is looking to diagnose or rule out only one type of sleeping disorder, which is Obstructive Sleep Apnea (OSA.) I have written a detailed article about OSA which you can read here.
The tests that occur in sleep labs use more sophisticated equipments and can therefore diagnose a much wider range of sleeping disorders, such as narcolepsy, hypersomnia, PLMD (Periodic Limb Movement Disorder), narcolepsy and sleep apnea.
I have written a detailed explanation of an “in-lab sleep study” here.
An HST is referred to as an “unattended” test because there is no qualified sleep technicians with you as you undergo the test.
An in-lab sleep study is an “attended” test because throughout the study you have a technician monitoring the study.
Why Have Home Sleep Tests?
The creation of Home Sleep Tests has been driven by three possibly four separate factors. Firstly, is the advancement of technology. Secondly is the push from health insurance companies for a cheaper way to assess people who have OSA.
Thirdly is the desperate need to properly diagnose more people with OSA. And a smaller contributing factor is that HSTs make a diagnosis of OSA available to people who otherwise find getting to a sleep lab very difficult.
As technology has improved, the ability to create portable sleep monitors has become possible. Technology has reduced the size of equipment, batteries are more powerful and the sensors that record the data are simpler.
Health Insurance Companies
The cost of an “in-lab” sleep study is about three times more expensive than an HST. An in lab sleep study will cost between $1000- $1300 whereas an HST costs between $200- $500.
Number of OSA Diagnoses
4% of adult men and 2% of adult women have a diagnosis of OSA. Yet it is thought that up to 14% of all adults in America have the condition. That is a huge number of people that could be struggling without any idea about what is wrong with them.
The complications that having OSA leads to can be life threatening. This includes an increased risk of having a heart attack and stroke and of developing type 2 diabetes.
Diagnosing a person with OSA and developing a treatment plan would save lives, give people the chance to live healthier lives and because of this, save massive amounts of money
Easier Access to a Diagnosis
Many groups of people would find getting to a sleep clinic very difficult. There are large numbers of people who find it physically difficult to leave their homes. These would include elderly people, people with physical disabilities and people who have mental health issues.
For these type of people the chance to have a diagnostic test at home instead of going somewhere else would be a lifeline.
A HST uses a fairly simple piece of equipment that comprises of a box (no bigger than a smart phone) that has several wires or sensors coming out of it. These wires are attached to different parts of your body. There are also a couple of belts to wear around your body.
The equipment is called a Portable Sleep Monitor (PSM).
The machine is a simpler version of the one used in sleep labs which is necessary because ordinary people who have no training in sleep medicine will be expected to use it.
It is also why a home sleep test can only diagnose obstructive sleep apnea and not any other sleeping disorders because the equipment needs to be as simple as possible.
Of course what has happened over time is that, like with everything else involving technology, the equipment has got slightly smaller, more sophisticated whilst still being easy to use.
There are up to 6 different pieces of information or data that a PSM is looking to collect.
Airflow– Using a small nasal canula
Respiratory Effort– Using two belts wrapped around your lower abdomen and your upper chest.
Oxygen Saturation– using a finger clip
Body Position– using a sensor built into the unit
Heart Rate– using the finger clip
Snoring– using the nasal canula.
Despite the progress of technology, any portable sleep monitor is limited in its capacity or accuracy compared to its much big brother which is used “in-lab”.
As I mentioned earlier, the only sleeping disorder that a home sleep test should be used to diagnose are cases of Obstructive Sleep Apnea (OSA).
Because of the limitations of the PSM, it should only be used in cases of moderate or severe OSA- not mild.
And the reason for this is that because of the PSM’s lack of accuracy or sensitivity, it tends to under diagnose OSA- there is no guarantee that it will record every occurence of a symptom during the night.
It may not record every pause in breathing or every gasp for breath that the patient makes. And so a patient with mild OSA where their breathing pauses are less often and shorter in duration might be analysed as not having OSA.
For patients who have been screened as potentially having moderate or severe OSA, the under reporting won’t be so much of an issue because enough data will be collected showing that they have OSA.
Getting a Home Sleep Test
Remember, an HST is an activity specific to a diagnosis of OSA.
However, there are some circumstances in which a HST shouldn’t take place- even if a diagnosis of OSA is highly likely.
These are when you have existing medical conditions that might “corrupt” the data and interfere with the process.
These medical conditions include pulmonary disease, neuromuscular disease or congestive heart failure.
If you have any of these conditions, then you will need to have a polysomnography at a sleep clinic.
An application for an HST is done through your physician.
Like many of us, you might go to your physician and have no clue about what is wrong. You just know that you are feeling unwell.
Typically you will have made an appointment with your physician to discuss some sleep related issue.
These issues would be very similar to the symptoms of OSA, which are;
- Excessive Daytime Sleepiness (EDS) *
- Loud snoring which is interrupted by periods of pauses in breathing.
- Sudden awakenings followed by gasping or choking.
- Suffering from a sore throat or dry mouth first thing in the morning.
- Inability to concentrate.
- Irritability and short temperedness.
*EDS is a persistent sleepiness that causes some people to act as if they are intoxicated and other people to try and take naps at inappropriate times such as at work or whilst driving.
And so you could be talking to your physician about how you feel so tired during the day that at times you fall asleep, which is EDS.
Or it could be that you discuss some disturbing behaviours that your bed partner (husband, wife, girlfriend or boyfriend) has observed whilst you are asleep- such as “breathing pauses” followed by you waking up gasping for air.
As you are talking, your physician should start thinking about OSA as a possible explanation.
Your physician might then give you a questionnaire to fill in to gather more details or they might do it with you at the time.
Depending on the answers, you could be set up with a home sleep study.
Alternatively, you might go to your physician armed with a OSA questionnaire filled out already.
There are numerous tests, quizzes and questionnaires that you can find online that will help you describe and focus your symptoms. It is very important to remember that using any of these is not a diagnosis- it is a screening tool to help you clarify your thoughts and be more prepared
Your physician will have their own way of doing things, so be careful how you tread!
There are three questionnaires that are widely used in screening for OSA. They are the STOP BANG questionnaire, the Berlin Questionnaire and the Preoperative questionnaire.
Each of these questionnaires vary in the detail that they ask for, but they are all well known in the field of sleep apnea.
You can read or download the questionnaires below.
Today’s The Day
Most health insurance companies and Medicare will cover at least part of the costs for a home sleep study.
Once it has been agreed that you can have an assessment, you will need to get the equipment.
There are a variety of ways that you will get hold of the equipment and it all depends on the company that you are use and where you live
It may be that you collect the equipment directly from a sleep clinic or from your physician’s office.
If this is the case then when you collect you should be given thorough instructions on how to use the equipment from a qualified person.
Hopefully this session will also give you the chance to ask any questions that you might have and to have a demonstration with the equipment.
Or it might be mailed directly to you. This was once only done in cases where people lived in very remote areas but in today’s world this is becoming a more widely available option- particularly because detailed “how to” videos can so easily be created and accessed.
On the day of the sleep study just follow your normal routine with a few modifications.
Some sleep clinics will ask you to make a few modifications to your routine, such as avoiding napping and drinking coffee after lunch. Your physician might ask you to stop taking your medication as well.
However, other sleep clinics will ask that you change nothing about your routine so that when you go in for your overnight observation, it is as close to the real you as possible!
Once you are ready for bed, you can put the portable sleep monitor on. It should not take longer than 20 minutes to put it all on.
Remember to wear it outside of a t-shirt or pyjama top. But just take your time, be patient and look at any instructions you might have. You should also have been given links to how to videos on the Internet.
Make sure that the equipment is not too tight or too loose on you but that it is comfortably snug. Once everything is connected, remember to turn the device on!
Even though wearing the PSM will be strange, try and relax. Although you might think that you won’t sleep that is highly unlikely. In the overwhelming majority of cases, enough data is collected for a diagnosis.
If you wake up in the middle of the night and need to go to toilet then you can do that without taking any of the equipment off. Also, if you wake up and one of the sensors has come loose, just re attach it.
Once you get out of bed in the morning, switch the device off and pack all the equipment away into its storage box.
You will have made arrangements to return the portable sleep monitor either to a sleep clinic or to your physician or perhaps you have to mail it back to the company?
It takes about two weeks for your results to be sent to your physician who will talk you through it and most importantly, set up a treatment plan.
In a very small number of cases, the HST will not have worked. This is normally because the equipment failed for some reason or another. Perhaps one of the sensors fell off during the night?
What tends to happen is that you are given the equipment to use on another night.