Major study casts doubt on ‘gold standard’ one-night sleep apnoea test

A test once considered the “gold standard” in diagnosing people with sleep apnoea may not be that gold after all.

Flinders University researchers tested the theory that the overnight polysomnography or “one-night” sleep study was still the best method to diagnose those who struggled with a good nights’s sleep.

More than 936 million people globally suffer from obstructive sleep apnoea, the stopping and starting of breathing during sleep.

The one-night test, which has been widely used since the 1970s, is considered the simplest, cheapest and most practical way to diagnose sleep apnoea, as it was believed symptoms would show up in just one night.

However, the Flinders University study has cast doubt over this belief because of sleep apnoea’s inconsistency from night to night.

Researchers studied 100 potential sleep apnoea patients by performing the one-night test while also monitoring their sleep over time outside of the laboratory.

“Our findings show that sleep apnoea can vary considerably from to the next, so if you only measure it once, you may not capture the true severity of the condition,” study lead author and sleep health expert Bastien Lechat said.

“In some participants, we saw clear differences between the single‑night result and the average across multiple nights, which suggests current diagnostic approaches may under or overestimate disease severity in some individuals.”

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Researchers also found relying on just one night’s testing could in some cases lead to patients being misdiagnosed, especially for those whose sleep was disrupted by the laboratory setting.

Flinders University professor in respiratory and sleep medicine and Southern Adelaide Local Health Network senior consultant Sutap Mukherjee said the inconsistency had helped improve understanding the condition.

“Our findings show that sleep apnoea is a dynamic disorder, and by capturing how it changes over time, we can build a much more accurate and clinically meaningful picture of a patient’s condition,” Professor Mukherjee said.

“These findings help explain why misdiagnosis occurs. It’s not just measurement error – it reflects real differences in how sleep apnoea presents from night to night.”

When the patients completed their sleep study over time at home – outside of the laboratory environment – the quality of sleep was improved.

“This study moves the field forward and it shows that to understand sleep apnoea properly, we need to look beyond one-night sleep diagnostics.” Professor Mukherjee said.

The multi-night approach and the patterns that it could show helped identify patients who were at risk of more serious issues, the researchers said.

Dr Lechat said repeated measurements combined with the one-night test would offer patients “a better chance of getting a diagnosis that truly reflects their condition”.

He said it also offered clinicians the opportunity to provide “more informed and personalised care”.