2 The diagnostic tests

Clinical need and practice

Obstructive sleep apnoea hypopnea syndrome

2.1

Obstructive sleep apnoea hypopnoea syndrome (OSAHS) is a condition in which the upper airway becomes blocked repeatedly during sleep. This can intermittently reduce airflow (hypopnoea) or stop airflow completely (apnoea). Both apnoea and hypopnoea can occur in the same night. Symptoms of sleep apnoea can include loud snoring, breathing pauses, gasping, choking, sleep disruption and unrefreshing sleep. Because of the sleep disturbance, symptoms may also occur during waking hours, including excessive sleepiness. Sleep disruption and excessive sleepiness can reduce quality of life, cognitive function and affect mental health. COPD–OSAHS overlap syndrome occurs in people who have both chronic obstructive pulmonary disease (COPD) and OSAHS.

2.2

In adults, OSAHS is associated with various conditions, such as overweight or obesity, hypertension, type 2 diabetes and cardiovascular disease. In children, the most common cause of OSAHS is adenotonsillar hypertrophy (enlarged tonsils or adenoids), which can partially obstruct the airway during sleep.

Care pathway and clinical need

2.3

Recommendations on detecting OSAHS and the care pathway can be found in NICE's guideline on obstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s and the British Thoracic Society's guideline for diagnosing and monitoring paediatric sleep-disordered breathing. NICE recommends home respiratory polygraphy as the initial test for OSAHS in people over 16. If home respiratory polygraphy is unavailable, home oximetry can be used. But oximetry alone may be inaccurate for differentiating between OSAHS and other causes of hypoxaemia in people with heart failure or chronic lung conditions. Hospital respiratory polygraphy or polysomnography can also be used if additional monitoring is needed.

2.4

Home respiratory polygraphy systems include wired components that need instructions for people to operate them and they can be uncomfortable to wear. Oximetry is a widely used alternative.

2.5

Expert clinical advice suggests that hospital sleep-testing capacity has reduced since the COVID‑19 pandemic, creating more reliance on home testing for sleep diagnostics. Some home-testing devices can be sent directly to the person by the manufacturer or NHS provider, which may increase access to home testing and reduce waiting times. This can potentially reduce time to diagnosis, leading to more timely treatment and symptom improvement. Newer home-testing devices may be easier to put on and operate than the devices currently used in the NHS, and may also be more comfortable to wear.

The interventions

2.6

Home-testing devices can be used for diagnosing OSAHS. The devices vary in terms of their indications, contraindications for use, physiological parameters measured, lifespan and their need for an internet connection or a smartphone. Table 1 highlights the device specifications including attachment details, mechanism of detection, and whether they need an internet connection or smartphone. See section 1.3 of the external assessment report in the committee papers for further details on the devices.

Table 1 Device specifications
Device name and cost Indicated age range Details and place of attachment Mechanism of detection Internet or smartphone needed

AcuPebble SA100

(£40 to £60 per test depending on the volume of sleep studies).

Adults.

Wireless sensor (throat).

Records sounds generated from physiological body processes including respiratory and cardiac functions.

A third-party oximeter can be added.

Internet: yes, needed for a healthcare professional to create a sleep study in the system and upload the data (this can be done when the device is received by a healthcare professional).

Smartphone or tablet: yes, manufacturer provides a smart device to do the test at no additional cost.

Brizzy

(£35 to £39 per test depending on volume; reusable device).

Over 3 years.

Device hub (waist belt).

Wired sensors (chin and forehead).

Measures jaw activity signals including mandibular movement. A third-party oximeter can be added.

Internet: no.

Smartphone: no.

NightOwl

(£90 per single-use device).

This technology is awaiting CE mark approval so cannot be used or included in the recommendations at this time.

13 years and over.

Wireless sensor (finger).

Consists of a photoplethysmography sensor and accelerometer that measure peripheral arterial tone (PAT) signal, oxygen saturation, body movement and pulse rate.

Internet: yes.

Smartphone: yes.

Sunrise

(£75 per single-use device, or £62 for orders over 100 devices).

Over 3 years.

Wireless sensor (chin).

Measures mandibular movement.

Internet: yes.

Smartphone: yes.

WatchPAT 300

(£50 per reusable device).

12 years and over.

Device hub (wrist strap).

Wired sensor (finger and chest).

Measures a proprietary PAT signal, heart rate, oximetry, body movement and position, snoring and chest motion.

Internet: no.

Smartphone: no.

WatchPAT ONE

(£80 per single-use device).

12 years and over.

Device hub (wrist strap).

Wired sensor (finger and chest).

Measures a proprietary PAT signal, heart rate, oximetry, body movement and position, snoring and chest motion.

Internet: yes.

Smartphone: yes.

The comparators

2.7

The comparators for people 16 years and over with OSAHS are home respiratory polygraphy or home oximetry.

2.8

The comparators for people under 16 years with OSAHS are home respiratory polygraphy or home pulse oximetry. Carbon dioxide monitoring may be used alongside these devices.