Sleep in persistent pain: screening for insomnia and sleep apnoea, and when to refer for CBT-I

"Poor sleep", noted

Most of us ask about sleep somewhere between "any pins and needles?" and "any questions for me?", write down "poor sleep" and move on. It's a reasonable instinct when the appointment is about a sore back. In persistent musculoskeletal pain, though, that one line in the notes may be hiding a treatable sleep disorder that is quietly working against everything else in the plan.

This article covers why sleep deserves a proper look in people with persistent pain, how to screen for the two sleep disorders that matter most in this group (insomnia and obstructive sleep apnoea), what the UK guidance says about when and how to refer, and what to say to patients in the meantime. It's written for chiropractors, physiotherapists, osteopaths, sports therapists and other clinicians who see people with long-standing pain. None of us diagnoses sleep disorders from the treatment couch, but we're often the clinician who sees the patient most often, and that makes us well placed to notice.

Why sleep belongs in the pain assessment

People living with chronic pain sleep differently, and it shows up on objective testing as well as in what they tell us. A 2018 meta-analysis by Mathias, Cant and Burke in Sleep Medicine pooled polysomnography studies and found that sleep onset latency, sleep efficiency, time awake after sleep onset and the number of awakenings were all significantly worse in adults with chronic pain than in healthy controls, with large effect sizes. The same review estimated the pooled prevalence of diagnosed sleep disorders in chronic pain at 44%, with insomnia the most common diagnosis, followed by restless legs syndrome and obstructive sleep apnoea.

The relationship runs in both directions, but not equally. Finan, Goodin and Smith (The Journal of Pain, 2013) reviewed the prospective and experimental evidence and concluded that sleep impairments reliably predict new incidents and exacerbations of chronic pain, and that sleep is a stronger, more reliable predictor of pain than pain is of sleep. They also discussed evidence that sleep disturbance may impair the body's own pain-inhibitory processes.

Afolalu, Ramlee and Tang (Sleep Medicine Reviews, 2018) looked at longitudinal studies in the general population: 16 studies covering about 61,000 participants. Declining sleep quality or quantity was associated with a two- to three-fold increase in the risk of developing a chronic pain condition, and improvements in sleep were associated with better physical functioning, although that effect was small.

None of this means poor sleep causes every case of persistent pain, or that fixing sleep will fix the pain. It does mean that a patient whose sleep is consistently broken is carrying a modifiable factor that is linked to worse pain and function, and that it's worth knowing which kind of sleep problem they have.

Two disorders worth separating

"Poor sleep" covers a lot of ground. For practical purposes in an MSK clinic, two questions do most of the work:

• Is this insomnia? Difficulty getting to sleep, staying asleep or waking too early, despite the opportunity to sleep, with an effect on daytime functioning.
• Could this be obstructive sleep apnoea? The upper airway narrows or closes during sleep, breathing stops or becomes shallow, and the person wakes or lightens their sleep to restart it. NICE's guideline on obstructive sleep apnoea/hypopnoea syndrome (OSAHS, NG202, 2021) describes how this can lead to disrupted sleep and excessive sleepiness.

The two can coexist, and the distinction matters because they are treated very differently. Insomnia is treated first with cognitive behavioural therapy for insomnia (CBT-I). Suspected sleep apnoea needs a sleep study and a sleep service. NICE's guidance on the digital CBT-I programme Sleepio (HTG624) says that people who may be at higher risk of other sleep disorders, including sleep apnoea, or who have comorbidities, should have a medical assessment before being referred to it. So it pays to think about apnoea first, even when the story sounds like insomnia.

Screening for insomnia

What counts as chronic insomnia

NICE's technology appraisal on daridorexant (TA922) describes long-term insomnia as symptoms on 3 or more nights a week for at least 3 months, with daytime functioning considerably affected. The 2023 European Insomnia Guideline (Riemann and colleagues, Journal of Sleep Research) recommends that insomnia is diagnosed through a clinical interview supported by sleep questionnaires and sleep diaries, and that polysomnography is used when another sleep disorder, such as sleep apnoea, is suspected.

Questions that fit into a subjective history

You don't need a separate appointment. A handful of questions gets you most of the way:

• How long does it usually take you to fall asleep?
• How often do you wake in the night, and how long are you awake for?
• Do you wake earlier than you want to and can't get back to sleep?
• How many nights a week is this happening, and for how long has it been going on?
• How does it affect you during the day: concentration, mood, energy, work?
• Is it the pain that wakes you, or do you wake and then notice the pain?

That last question doesn't make a diagnosis, but it often opens a more useful conversation than "how are you sleeping?"

The Insomnia Severity Index

The Insomnia Severity Index (ISI) is a short, 7-item questionnaire that patients can complete in a couple of minutes. In a validation study by Morin and colleagues (Sleep, 2011), a cut-off score of 10 detected insomnia cases in a community sample with 86.1% sensitivity and 87.7% specificity. In the clinical sample, a reduction of about 8.4 points was associated with moderate improvement after treatment, which makes it useful for tracking change as well as for screening.

A score of 10 or more is a reason to talk about it and, if it fits the clinical picture, to recommend that the patient speaks to their GP. It isn't a diagnosis on its own.

A sleep diary

A one- or two-week sleep diary (time into bed, estimated time to fall asleep, night wakings, final waking time, time out of bed, and a rating of sleep quality) gives the GP or sleep service something concrete to work with. It also often surprises patients, in a helpful way, when they see the pattern written down.

Screening for obstructive sleep apnoea

When to suspect it

NICE NG202 recommends taking a sleep history and assessing for OSAHS if a person has 2 or more of these features:

• snoring
• witnessed apnoeas (a bed partner describes pauses in breathing)
• unrefreshing sleep
• waking headaches
• unexplained excessive sleepiness, tiredness or fatigue
• nocturia (waking from sleep to urinate)
• choking during sleep
• sleep fragmentation or insomnia
• cognitive dysfunction or memory impairment.

Notice that "sleep fragmentation or insomnia" is on the list. A patient with persistent pain who says they wake repeatedly and feel unrefreshed already has 2 features.

NICE also asks clinicians to be aware that OSAHS is more common in people with obesity or overweight (including in pregnancy), treatment-resistant hypertension, type 2 diabetes, cardiac arrhythmia (particularly atrial fibrillation), stroke or TIA, chronic heart failure, moderate or severe asthma, polycystic ovary syndrome, Down's syndrome, non-arteritic anterior ischaemic optic neuropathy, hypothyroidism and acromegaly. Many of these will already be in the medical history you take.

The Epworth Sleepiness Scale and STOP-Bang

NG202 recommends the Epworth Sleepiness Scale for the preliminary assessment of sleepiness, and suggests considering the STOP-Bang questionnaire alongside it.

• Epworth Sleepiness Scale. Developed by Johns (Sleep, 1991), it asks people to rate how likely they are to doze off in 8 situations commonly encountered in daily life. It measures general daytime sleepiness.
• STOP-Bang. Eight yes/no items: Snoring, Tiredness, Observed apnoea, high blood Pressure, BMI, Age, Neck circumference and male Gender, giving a score from 0 to 8. Chung, Abdullah and Liao (Chest, 2016) describe a score of 0 to 2 as low risk for moderate to severe sleep apnoea and 5 to 8 as high risk, with mid-range scores of 3 or 4 needing further criteria, such as BMI, to classify risk.

NICE adds an important caution: do not use the Epworth score alone to decide whether someone needs referral, because not everyone with OSAHS is excessively sleepy. A patient with persistent pain may describe fatigue rather than sleepiness, and a low Epworth score shouldn't close the question if the other features are there.

What the referral should include

NG202 lists what should be in a referral letter to a sleep service: assessment scores, how sleepiness affects the person, comorbidities, occupational risk, and oxygen saturation and blood gas values if available. In most MSK settings, the practical route is a clear letter to the patient's GP with the features you noticed and the scores you recorded, so they can decide on referral. Sleep services prioritise people who drive for a living, people whose jobs need vigilance for safety, and people with unstable cardiovascular disease, among others, so mention occupation.

Diagnosis is made by the sleep service, usually starting with home respiratory polygraphy, an overnight test done at home.

Driving and daytime sleepiness

This is the part that shouldn't wait for the next appointment. GOV.UK guidance on excessive sleepiness and driving says that people must tell the DVLA if they have confirmed moderate or severe obstructive sleep apnoea with excessive sleepiness, or any other sleep condition that has caused excessive sleepiness for at least 3 months, including suspected or confirmed mild sleep apnoea. They must not drive until they're free from excessive sleepiness or their symptoms are under control and they're following any necessary treatment. The DVLA's guidance for medical professionals sets out the detail.

If a patient tells you they've nodded off at the wheel, or are struggling to stay awake while driving, say so plainly, record the conversation, point them to the GOV.UK guidance and make sure their GP knows. It's a short, uncomfortable conversation and a very important one.

Referring for CBT-I

Why CBT-I, and why not just sleep hygiene

The European Insomnia Guideline recommends CBT-I as the first-line treatment for chronic insomnia in adults of any age, including people with comorbidities, and says it can be delivered face to face or digitally. The American Academy of Sleep Medicine's 2021 guideline (Edinger and colleagues, Journal of Clinical Sleep Medicine) makes a strong recommendation for multicomponent CBT-I. It also suggests that stimulus control, sleep restriction therapy and relaxation therapy can each be used as single-component treatments, and suggests that clinicians do not use sleep hygiene advice as a single-component therapy.

That last point matters in practice. A leaflet about caffeine and screens is fine as part of a wider plan, but on its own it isn't the treatment the guidelines recommend for chronic insomnia.

Does it help people with chronic pain?

Selvanathan and colleagues (Sleep Medicine Reviews, 2021) carried out a systematic review and meta-analysis of randomised trials of CBT-I in people with chronic pain. Pooling 12 trials (762 participants), CBT-I produced a large improvement in sleep quality after treatment (standardised mean difference 0.89), which was still moderate at follow-up of up to 12 months (0.56). The effect on pain intensity was small (0.20), and there was a moderate effect on depression (0.44). There was no clear effect on anxiety or fatigue.

So the honest message for patients is that CBT-I reliably helps sleep in people with chronic pain, may help their pain a little, and may help mood. That's worth having, and it's a much better offer than "try to get an early night".

How people access it in the UK

NICE's TA922 notes that CBT-I is the standard first treatment for long-term insomnia after sleep hygiene advice, but that access varies across the UK. NICE's HealthTech guidance on Sleepio (HTG624) recommends that digital self-help programme, which includes CBT-I, as a cost-saving option in primary care for people with insomnia who would otherwise be offered sleep hygiene advice or sleeping pills, after a medical assessment for those at higher risk of other sleep disorders. What's available locally will vary, so the GP is the usual starting point.

What to say to patients

Some phrasing that tends to land well:

• "Sleep and pain feed into each other. Looking after one can make the other easier to manage."
• "From what you've described, it's worth having a proper look at your sleep. I'd like you to talk to your GP about it, and I'll write to them with what we've found."
• "There's a specific talking therapy for insomnia called CBT-I. It's the recommended first treatment, and there are digital versions as well as face-to-face ones."
• If apnoea features are present: "Snoring, waking unrefreshed and dozing during the day can be signs of a breathing problem during sleep. It's common, it's treatable, and it's worth getting checked."

Keep the treatment plan for their pain going alongside this. A sleep referral sits alongside the work you're already doing together.

What changes on Monday morning

1. Ask about sleep properly. Time to fall asleep, night wakings, early waking, nights per week, how long, and daytime impact.
2. Use a score. The ISI takes a couple of minutes. A score of 10 or more is a prompt to discuss and consider referral.
3. Check for apnoea before assuming insomnia. Two or more NG202 features, including sleep fragmentation, is a reason to assess further.
4. Pair the Epworth with STOP-Bang. Don't let a low Epworth score close the question, because not everyone with sleep apnoea is sleepy.
5. Ask about driving and occupation. Sleepiness at the wheel needs the conversation today, a note in the record and the GOV.UK guidance.
6. Write a useful GP letter. Features, scores, comorbidities, how sleepiness affects them, and their job.
7. Recommend CBT-I, not just sleep hygiene. It's the first-line treatment for chronic insomnia, including in people with chronic pain.
8. Keep treating the pain. Better sleep and good MSK care work together.

Sleep rarely gets top billing in an MSK appointment. A few structured questions, two short questionnaires and a clear letter are often enough to get a patient onto the right pathway, and for many people with persistent pain that's one of the more useful things we can do.

Assessing sleep disorders in people with chronic pain and building integrated, patient-centred care plans are covered in ManualCPD's The Pain-Sleep Nexus: Unlocking Recovery course, written for all professions. ManualCPD offers online, on-demand CPD for chiropractors, physiotherapists, osteopaths and sports therapists, broken into manageable chunks you can work through between patients, at lunch or after clinic. Every ManualCPD course is accredited by The CPD Group (Provider 788442), and you receive a CPD certificate on completion.