Evidence
This page contains a snapshot of featured content which highlights evidence addressing key clinical questions including areas of uncertainty. Please see the main topic reference list for details of all sources underpinning this topic.
BMJ Best Practice evidence tables
Evidence tables provide easily navigated layers of evidence in the context of specific clinical questions, using GRADE and a BMJ Best Practice Effectiveness rating. Follow the links at the bottom of the table, which go to the related evidence score in the main topic text, providing additional context for the clinical question. Find out more about our evidence tables.
This table is a summary of the analysis reported in a guideline (underpinned by a systematic review) that focuses on the above important clinical question.
Confidence in the evidence is moderate or low to moderate where GRADE has been performed and there may be no difference in effectiveness between the intervention and comparison for key outcomes.
Population: People with suspected OSA
Intervention: Portable HSAT
Comparison: In-laboratory attended PSG
| Outcome | Effectiveness (BMJ rating)? | Confidence in evidence (GRADE)? |
|---|---|---|
Patients incorrectly classified as not having OSA (false negative) | Favours comparison | Low to High ᵃ |
Sleepiness (Epworth Sleepiness Scale) | No statistically significant difference | High |
Quality of life | No statistically significant difference | Moderate to High ᵇ |
CPAP Adherence (hours per night) | No statistically significant difference | Moderate |
CPAP Adherence (number of nights > 4 hours) | No statistically significant difference | High |
Failure to complete diagnostic algorithm | See note ᶜ | Low |
Recommendations as stated in the source guideline We recommend that PSG or HSAT with a technically adequate device be used for the diagnosis of OSA in uncomplicated adult patients presenting with signs and symptoms that indicate an increased risk of moderate -to-severe OSA. We recommend that if a single home sleep apnea test is negative, inconclusive, or technically inadequate, polysomnography be performed for the diagnosis of OSA.
Note The guideline task force stated that HSAT is less sensitive than PSG in detecting OSA, with false negative results potentially harming patients due to the denial of essential treatment. A repeat HSAT is therefore not recommended when the initial test is negative, inconclusive, or technically inadequate, with PSG recommended instead. The guideline task force determined that the critical outcome for diagnostic accuracy assessment was the number of false negative results. Critical clinical outcomes included sleepiness, quality of life, and CPAP adherence. Depression and cardiovascular outcomes were also considered critical outcomes; however, no studies reported these outcomes. Failure to complete the diagnostic algorithm was also a critical outcome for repeat testing after a negative, inconclusive, or technically inadequate HSAT. ᵃ GRADE assessment varied across different HSAT devices and when using different cutoffs of the apnoea hypopnoea index (AHI). ᵇ Five different quality-of-life measurements were reported, none showed any statistically significant difference however the GRADE rating ranged from Moderate to High. ᶜ Results reported narratively. In one RCT 30% (10/33) adults who had technically inadequate HSATs and 16% (14/88) with low AHI on HSAT failed to go on to have PSG as per the diagnostic algorithm.
This evidence table is related to the following section/s:
This table is a summary of the analysis reported in a guideline (underpinned by a systematic review) that focuses on the above important clinical question.
Confidence in the evidence is moderate or low to moderate where GRADE has been performed and the intervention may be more effective/beneficial than the comparison for key outcomes.
Population: Patients with obstructive sleep apnoea
Intervention: Oral appliance therapy
Comparison: No therapy or CPAP ᵃ
| Outcome | Effectiveness (BMJ rating)? | Confidence in evidence (GRADE)? |
|---|---|---|
Oral appliance therapy versus no therapy (before and after studies) | ||
Apnoea-Hypopnoea Index/Respiratory Disturbance Index/Respiratory Event Index (AHI/RDI/REI) | Favours intervention | Moderate |
Minimum oxygen saturation | Favours intervention | Moderate |
Arousal index | Favours intervention | Moderate |
Oxygen Desaturation Index (ODI) | Favours intervention | Moderate |
Sleep efficiency | No statistically significant difference | Moderate |
REM | No statistically significant difference | Low |
Oral appliance therapy versus CPAP | ||
AHI/RDI/REI | Favours comparison | Moderate |
Oxygen saturation | Favours comparison | Moderate |
Arousal index | Favours comparison | Moderate |
Sleep efficiency | No statistically significant difference | Moderate |
REM | No statistically significant difference | Low |
ODI | Favours comparison | Low |
Epworth Sleepiness Scale (ESS): daytime sleepiness | No statistically significant difference | Low |
Quality of life (SF-36) | Favours comparison | Low |
Systolic blood pressure | Favours intervention | Low |
Diastolic blood pressure | No statistically significant difference | Low |
Adherence (subjective; hours/night) | Favours intervention | Low |
Discontinuation of therapy from side effects | No statistically significant difference | Moderate |
Recommendations as stated in the source guideline We recommend that sleep physicians consider prescription of oral appliances, rather than no treatment, for adult patients with obstructive sleep apnoea who are intolerant of CPAP therapy or prefer alternate therapy.
Note The guideline committee stated that while CPAP is the first-line treatment for adults with obstructive sleep apnoea, adherence to oral appliance therapy is subjectively better, and the benefits of using oral appliance therapy outweigh the risks of not using it. ᵃ There was insufficient data for the guideline committee to compare oral appliance therapy to other alternate (non-CPAP) therapies.
This evidence table is related to the following section/s:
Cochrane Clinical Answers
Cochrane Clinical Answers (CCAs) provide a readable, digestible, clinically focused entry point to rigorous research from Cochrane systematic reviews. They are designed to be actionable and to inform decision making at the point of care and have been added to relevant sections of the main Best Practice text.
- How do behavioral interventions compare with usual care for promoting continuous positive airway pressure (CPAP) device usage in adults with obstructive sleep apnea?
- How do supportive interventions compare with usual care for promoting continuous positive airway pressure (CPAP) device usage in adults with obstructive sleep apnea?
- How do educational interventions compare with usual care for promoting continuous positive airway pressure (CPAP) device usage in adults with obstructive sleep apnea?
- How does auto‐continuous positive airway pressure (CPAP) compare with fixed‐pressure CPAP in time of machine use for adults with obstructive sleep apnea (OSA)?
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