Frequency of snoring and hypertension better indicator for sleep apnoea
Snoring frequency and hypertension is proven to better screen out obstructive sleep apnoea (OSA) in the general population than the Berlin questionnaire (BQ), a University of WA study has found.
According to the study, the BQ, a popular sleep apnoea screening tool, is best suited for use in primary care populations and has a minimal success rate in picking up OSA cases within the general population.
Lead author and PhD student Laila Simpson says she found using questions on snoring frequency and hypertension increased the probability of having a general population sample with a lower probability of having moderate-severe OSA than using the BQ.
“The BQ was not a very good instrument for diagnosing or picking up cases of OSA in a general population,” Ms Simpson says.
“The scale was developed for primary care and not for the general population, so it was not surprising that it did not do so well in that population.”
Ms Simpson says there are a lot of screening tools used for OSA but none of them are as good as actually measuring sleep.
“Sleep apnoea has to be formally diagnosed using quite a lot of measurements and using a questionnaire you lose a lot of details,” she says.
“The best case scenario is always to use some sort of formal measurement of sleep, but in failing that, the BQ performs best in primary care and clinical samples and much worse in general population samples.
“If you use a questionnaire in a sample that has a high prevalence of the disorder, that makes it more successful at picking up the cases and in the general population the prevalence is far lower than it would be in a primary care population.”
Ms Simpson says in that circumstance, the BQ fails to pick up many OSA cases.
“You can still pick up OSA cases using the Berlin questionnaire, it is just that you have a lot of missed cases and you are likely to include people who are not actually cases, if you went and followed them up.”
Ms Simpson says the study highlights that there is still a lot of undiagnosed OSA in the population.
“We need better ways of characterising OSA so we need to use more technology that measures sleep in order to characterise our research populations.”