PSQI or Pittsburgh Sleep Quality Index is a self-reported questionnaire about sleep. It can help improve the duration and quality of sleep by helping people understand what prevents them from getting enough quality shut-eye.
Complaints about poor and disrupted sleep are common among people. It is shown that sleep disorders affect people all around the world. Most common ones are insomnia, obstructive sleep apnea, restless legs syndrome, circadian rhythm sleep disorder, and hypersomnia. Not treating these disorders can lead to many health problems and potentially life-threatening symptoms. They often affect the development of other health conditions as well. Inadequate sleep can lead to impaired cognitive ability, attention deficit, stress, anxiety, depression, poor mood, weight gain, high blood pressure, heart disease, diabetes, and many other conditions. It affects your mood, daily performance, and overall health and the quality of life.
Adequate detection is essential when it comes to different health and sleep disorders. That’s why clinicians and researchers have tried to develop the best method for detecting sleep problems in the general population. A perfect detection technique should be cheap, easy to administer, quick, and it should give the most accurate results. It is tough to accomplish all of the mentioned criteria, so some parts need to be sacrificed to get the adequate technique. Pittsburgh sleep quality index (PSQI) is a method made to asses the sleep quality in individuals.
PSQI is a self-reported questionnaire about sleep. It looks into one month period and tries to rate your sleep quality based on your answers. PSQI is relatively new, as it was developed by Buysse and colleagues at the University of Pittsburgh in 1988. It has been created after the observation that it is widespread that people who suffer from mental disorders also have a much higher prevalence of sleep problems. For instance, people with a generalized anxiety disorder (GAD) are much more likely to have troubles falling asleep, as well as maintaining it and going back to it after they have been awoken. They are also more likely to report a sleep that wasn’t restorative, as they feel tired after waking up.
PSQI consists of 19 self-report items, and it may also include five related questions for your bed partner. However, only these 19 items reflect a final score, of which 4 are open-ended questions while 15 require a rating of 0 to 3. Questions are grouped into seven individual components, that then produce a score. Seven areas that it looks into are subjective sleep quality, sleep latency (the time it takes you to fall asleep), sleep duration, sleep efficiency (how much time of total bedtime you spent sleeping), sleep disturbances, the use of sleep medication, and daytime functionality. PSQI is practical to use as it only takes 5 to 10 minutes, and you don’t need to be additionally trained to interpret the scores.
Questions cover a wide area of sleep. First, you’ll be asked to state your usual bed and rising time, as well as how long it takes you to drift away and how much rest you get. Other questions might be about your nighttime wakings, nightly trips to the bathroom, snoring, coughing, problems with breathing, feeling hot or cold, having bad dreams or body pains. Some questions include the use of medication and alcohol. There are also some items to rate your energy levels during the day, as well as how much of a mental effort it takes to do things daily. You’ll rate those questions on a scale from “very good” to “very bad,” and there are usually four options to choose from so that you can pick the one that suits you best.
Each segment is rated from 0 to 3, 0 meaning that there are no sleep disturbances and 3 with the least sleep quality. That means that the overall score can range between 0 and 21. PSQI score of over five is considered to indicate sleep problems in a person taking the test, and the higher the score, the worse the quality of sleep.
PSQI is one of the most widely used health-assessment tools in both clinical and non-clinical populations. It is also applicable everywhere around the Earth, so it has been translated to over 55 languages so far.
Validity and reliability of PSQI have been widely confirmed. It can distinguish between people with regular sleeping patterns and the ones who have sleeping problems pretty accurately. However, it can not give us an answer on what exactly is wrong with our sleep. For that to happen, further sleep study called polysomnography is needed.
Like all self-report health questionnaires, PSQI has its strengths and flaws. Its primary advantages are that it is cost-effective, easy to administer, and it has high patient compliance. However, it is self-reported, so it is a subjective reality of a person who fills it. It is possible that they can exaggerate or minimize scores, and the way that it is administered can affect the ratings as well. Also, two people with the same score can have very different sleep conditions. As it is relatively new, it needs more investigating before giving a final verdict of its quality.
One systematic review from 2018 tried to look into the dimensionality of the PSQI. While it is a useful tool, they found a few shortcomings, and they concluded that the various PSQI factor structures might need further investigation.
PSQI is not used as a diagnostic tool, but as a sleep quality assessment. If you get a score that indicates poor sleep quality, an objective diagnosis technique is needed. That’s when polysomnography comes in place. It is an overnight sleep study conducted in a sleep facility. You’ll be observed throughout the night, with a bunch of electrodes attached to you to monitor your brain waves, limb and chest movement, respiration, heart rate, as well as snoring and other noises you might produce during the night. After that, a sleep specialist goes through the obtained information, and they discuss further treatment based on their findings. PSQI is mainly used for that, to determine who has sleep problems that require further objective investigation. It saves a lot of money, since questions are self-explanatory, so no specialist is needed while filling it. It is a kind of like an advanced sleep diary, with specific questions to assess your sleep quality adequately.
One study from 2008 also looked at the effectiveness of PSQI and Epworth sleepiness scale compared to polysomnography findings and found that the objectiveness of these questionnaires is not at the satisfying level.
Lengthy questionnaires tend to bore the participants, and they might be more inaccurate. An article from 2018 suggests that maybe we need to shorten the PSQI. They had a group of 1246 college students who filled both standard and short versions of the survey. In contrast to the 19 item questionnaire, this new version had only 13 items. It turned out that the short PSQI was just as reliable at predicting sleep problems in younger adults as the standard PSQI.
If you are having sleep problems, taking a PSQI might show you where you stand. You should aim to develop a healthy sleep routine to improve the quality of your nightly rest. Go to bed and wake up at the same time every day, make your bedroom free of distractions and don’t use the electronic devices one hour before bedtime. Try to do something that relaxes you to help you fall asleep faster, and you should always try to lead a healthy lifestyle. Eating right and exercising are very important for good sleep, and proper rest is also essential for your health and the overall quality of life.
Dusan is a biologist, a science enthusiast and a huge nature lover. He loves to keep up to date with all the new research and write accurate science-based articles. When he’s not writing or reading, you can find him in the kitchen, trying out new delicious recipes; out in the wild, enjoying the nature or sleeping in his bed.
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