You answered eight questions about how sleep problems affect your daily life and got a T-score. Unlike most assessments that simply add up points, the PROMIS uses T-scores, a standardized system where 50 is average and every 10 points represents one standard deviation from the norm. Here's what your score actually tells you.
The quick answer
| T-Score | What it means |
|---|---|
| Below 55 | Normal range: your sleep-related functioning is similar to most people |
| 55-59 | Mild impairment: noticeable but manageable effects |
| 60-69 | Moderate impairment: significant impact on daily functioning |
| 70+ | Severe impairment: major limitations requiring attention |
The key threshold is 55. Below this, your daytime functioning related to sleep is within normal limits. Above it, you're experiencing more impairment than most people.
Understanding your T-score
T-scores can feel abstract, so here's a practical way to think about them:
T = 50: You're exactly average. Half the population has more impairment, half has less.
T = 60: You have more sleep-related impairment than about 84% of people. This is one standard deviation above average, noticeable and clinically meaningful.
T = 70: You have more impairment than about 98% of people. This is two standard deviations above average, severe and definitely affecting your life.
T = 40: You have less impairment than average, better daytime functioning than most people despite whatever sleep issues you might have.
What this assessment measures (and what it doesn't)
This assessment specifically measures daytime consequences of poor sleep, not sleep quality itself. It asks about:
- Feeling tired and sleepy during the day
- Difficulty getting things done because of sleepiness
- Problems concentrating
- Feeling irritable
- Struggling to stay awake
- Waking up feeling unrefreshed
It doesn't ask about how well you sleep at night, how long it takes to fall asleep, or how often you wake up. That's intentional. You can have poor nighttime sleep with minimal daytime impairment, or feel terrible during the day despite apparently adequate sleep. This measure focuses on the functional impact.
What your specific score suggests
T-score below 50 (better than average)
Your sleep-related daytime functioning is better than most people. Either you're sleeping well, or your body handles suboptimal sleep without much functional impact. No concerns here.
T-score 50-54 (average range)
You're experiencing the level of sleep-related impairment that most adults do. Some tiredness, some foggy days, normal life. This doesn't mean you couldn't benefit from better sleep, but you're not experiencing unusual impairment.
T-score 55-59 (mild impairment)
You're experiencing more daytime impairment than most people. You might be:
- Frequently tired despite getting what seems like enough sleep
- Noticing your concentration isn't what it used to be
- Reaching for more caffeine than you'd like
- Feeling irritable and attributing it to tiredness
This level often prompts people to start paying attention to their sleep habits.
T-score 60-69 (moderate impairment)
This is where sleep problems are significantly affecting your daily life. You likely:
- Struggle to stay alert during meetings or while driving
- Have difficulty completing tasks that require sustained attention
- Feel exhausted most days regardless of how much you slept
- Notice your mood and relationships suffering
At this level, it's worth investigating the cause. Is it simply not enough sleep time? Poor sleep quality? An underlying sleep disorder?
T-score 70+ (severe impairment)
Fewer than 2% of people experience this level of impairment. At this level:
- Daily functioning is substantially compromised
- You may be falling asleep unintentionally
- Work performance and relationships are likely affected
- There may be safety concerns (driving, operating equipment)
A score this high warrants evaluation by a healthcare provider. This could indicate a sleep disorder, a medical condition affecting sleep, or severe sleep deprivation.
The eight questions explained
"I had a hard time getting things done because I was sleepy"
This measures functional impairment, whether sleepiness is actually preventing you from accomplishing what you need to do, not just making things harder.
"I felt alert when I woke up" (reverse-scored)
Waking alertness reflects sleep quality. People with restorative sleep wake up feeling ready to start the day. If you consistently wake up groggy regardless of sleep duration, your sleep may not be restorative.
"I felt tired"
General tiredness throughout the day, that sense of physical and mental depletion that goes beyond momentary sleepiness.
"I had problems during the day because of poor sleep"
A broad question capturing any daytime difficulties you attribute to poor sleep, whether that's performance, mood, or physical issues.
"I had a hard time concentrating because of poor sleep"
Cognitive effects are often the first sign of inadequate sleep. If you're having to re-read paragraphs or losing track of conversations, poor sleep may be the culprit.
"I felt irritable because of poor sleep"
Sleep deprivation lowers the threshold for frustration. If small things are setting you off more than usual, consider whether sleep is a factor.
"I was sleepy during the daytime"
Daytime sleepiness beyond normal afternoon dips can indicate insufficient sleep, poor sleep quality, or a sleep disorder.
"I had trouble staying awake during the day"
This is more severe than feeling sleepy, actually struggling to maintain wakefulness. If you're fighting to keep your eyes open during activities, that's concerning.
Why this assessment matters
Many people normalize chronic tiredness. "Everyone's tired." "I just need more coffee." "I'll catch up on sleep this weekend."
This assessment gives you an objective comparison point. If your T-score is 65, you're not just "a little tired." You're experiencing more impairment than 93% of people. That's useful information when deciding whether to address your sleep.
It's also useful for tracking change. If you start a sleep intervention (better sleep hygiene, treating sleep apnea, adjusting medications), you can retake the assessment and see if your daytime functioning actually improves.
What to do based on your score
If your score is below 55
Your sleep-related functioning is normal. If you're still curious about optimizing your sleep, standard sleep hygiene recommendations apply, but you're not in clinical territory.
If your score is 55-59
Consider whether simple changes might help:
- Are you getting enough sleep time? (Most adults need 7-9 hours)
- Is your sleep schedule consistent?
- Are there obvious sleep disruptors (caffeine, alcohol, screens, noise)?
- Could stress or anxiety be affecting your sleep?
If your score is 60-69
It's worth talking to a healthcare provider. At this level, the impairment is significant enough that:
- Simple sleep hygiene may not be sufficient
- There may be an underlying cause worth investigating
- Treatment could meaningfully improve your quality of life
If your score is 70+
See a healthcare provider. This level of impairment suggests something beyond "I should go to bed earlier." Possibilities include:
- Sleep disorders (apnea, insomnia, restless legs)
- Medical conditions affecting sleep
- Medication side effects
- Mental health conditions
A sleep study or specialist evaluation may be appropriate.
Common questions
My score is high but I think I sleep enough. What's going on?
Sleep duration isn't everything. Sleep quality matters too. You could be getting 8 hours of fragmented, non-restorative sleep. Sleep apnea, for example, causes repeated micro-awakenings that people often don't remember but that destroy sleep quality.
I've always been tired. Is this just how I am?
Maybe, but maybe not. Many people have undiagnosed sleep disorders or simply haven't prioritized sleep. A T-score in the impaired range suggests something could potentially improve.
Can I compare my score to someone else's?
Yes, that's the point of T-scores. If you're at 62 and your partner is at 48, you're experiencing significantly more sleep-related impairment. Whether that's due to different sleep quality, different biology, or different sleep disorders varies.
How often should I retake this?
If you're tracking a sleep intervention, monthly is reasonable. The 7-day recall window means you're capturing recent functioning, not long-term patterns.
The bottom line
Your PROMIS Sleep-Related Impairment score tells you how much poor sleep is affecting your daily life compared to the general population. Scores below 55 are normal. Scores of 55-59 suggest mild impairment worth monitoring. Scores of 60 and above indicate significant impairment that likely warrants attention, whether that's sleep hygiene changes, evaluation for sleep disorders, or addressing underlying conditions. The score doesn't tell you why you're impaired, but it does confirm whether the impairment is real and significant.