Screening and Detecting Obstructive Sleep Apnoea in a Memory Clinic Setting: An Underdiagnosed At-Risk Population?
Authors List
Aaron Lam1,2, Angela D’Rozario1,2, Camilla Hoyos1,2, Catriona Ireland1, Johannes Michaelian1, Dexiao Kong1, Loren Mowszowski1, Ron Grunstein1,2, Sharon L Naismith1
1Woolcock Institute of Medical Research, New South Wales, Australia
2The University of Sydney, New South Wales, Australia
Introduction
The prevalence of obstructive sleep apnoea (OSA) increases with ageing. In sleep and cardiovascular clinics, rates of OSA are often higher than in community settings. To date, few studies have examined OSA in a memory clinic setting. Given the known association between OSA and increased risk of cognitive decline and dementia, screening for OSA in memory clinics may be warranted. Our study aimed to 1) determine rates and severity of OSA in a memory clinic setting as determined by polysomnography (PSG); 2) compare rates of OSA screening tools including self-report, STOP-Bang, and WristOx pulse oximeter against PSG; 3) determine the predictive validity of STOP-Bang questionnaire compared to PSG-confirmed OSA; and, 4) determine the correlation and agreement between oxygen desaturation index (ODI) captured by WristOx and PSG.
Methods
The current study reports data captured between 2009-2022 from the Healthy Brain Ageing (HBA) Clinic, a specialist memory clinic providing neuropsychological, medical, and mood assessment for adults aged over 50 with new cognitive and/or mood concerns. Here, we measured rates and severity of OSA through PSG, self-reported diagnosis of OSA, the STOP-Bang questionnaire, and the Nonin WristOx 3150 pulse oximeter. To determine the predictive validity of STOP-Bang we conducted a receiver operating curve analysis. To determine the correlation and agreement between WristOx and PSG, we conducted Spearman’s correlation and Bland-Altman plot.
Results
A total of 1016 participants (mean age=66.9 (SD = 9.0), mean MMSE=28.3 (SD=2.2), male=436 (43%)) were included for analysis. Despite only 15% self-reporting (n=152/1016) a prior diagnosis of OSA, PSG data (subset n=505) showed 76% met the criteria for OSA. In terms of PSG-confirmed OSA severity, 35% had mild, 25% had moderate, and 15% had severe OSA. STOP-Bang (n=75) suggested that 49% were low risk, 55% were moderate risk and 16% were high risk for moderate-to-severe OSA. Using a WristOx (n=137) ODI cut-off of 5, 84% of participants were classified as having OSA. The STOP-Bang demonstrated low predictive validity for PSG-confirmed moderate-severe OSA (AUC=0.631, p=0.172). There was a significant moderate correlation between ODI from WristOx and PSG (rho=0.494, p=0.001). Bland-Altman plot demonstrated a mean difference between ODI obtained from WristOx and PSG of 0.84 (SD=11.6, with 95% limits of agreement from -21.9 to 23.6).
Conclusion
Although the primary concern for participants attending memory clinics is cognition, rates of OSA are high and appear to be severely underdiagnosed within this context. Unfortunately, while the STOP-Bang questionnaire has been validated for use in other clinical settings, the predictive validity for OSA in those attending a memory clinic appears to be low. Objective OSA screening tools (e.g., pulse oximetry) may be more beneficial.
Research Funding Source: The National Health and Medical Research Council (NHMRC) Centre of Research Excellence to Optimise Sleep in Brain Aging and Neurodegeneration (CogSleep CRE) (APP: 1152945); NHMRC Boosting Dementia Leadership (Fellowship No. 1135639 to S.L.N.
Aaron Lam1,2, Angela D’Rozario1,2, Camilla Hoyos1,2, Catriona Ireland1, Johannes Michaelian1, Dexiao Kong1, Loren Mowszowski1, Ron Grunstein1,2, Sharon L Naismith1
1Woolcock Institute of Medical Research, New South Wales, Australia
2The University of Sydney, New South Wales, Australia
Introduction
The prevalence of obstructive sleep apnoea (OSA) increases with ageing. In sleep and cardiovascular clinics, rates of OSA are often higher than in community settings. To date, few studies have examined OSA in a memory clinic setting. Given the known association between OSA and increased risk of cognitive decline and dementia, screening for OSA in memory clinics may be warranted. Our study aimed to 1) determine rates and severity of OSA in a memory clinic setting as determined by polysomnography (PSG); 2) compare rates of OSA screening tools including self-report, STOP-Bang, and WristOx pulse oximeter against PSG; 3) determine the predictive validity of STOP-Bang questionnaire compared to PSG-confirmed OSA; and, 4) determine the correlation and agreement between oxygen desaturation index (ODI) captured by WristOx and PSG.
Methods
The current study reports data captured between 2009-2022 from the Healthy Brain Ageing (HBA) Clinic, a specialist memory clinic providing neuropsychological, medical, and mood assessment for adults aged over 50 with new cognitive and/or mood concerns. Here, we measured rates and severity of OSA through PSG, self-reported diagnosis of OSA, the STOP-Bang questionnaire, and the Nonin WristOx 3150 pulse oximeter. To determine the predictive validity of STOP-Bang we conducted a receiver operating curve analysis. To determine the correlation and agreement between WristOx and PSG, we conducted Spearman’s correlation and Bland-Altman plot.
Results
A total of 1016 participants (mean age=66.9 (SD = 9.0), mean MMSE=28.3 (SD=2.2), male=436 (43%)) were included for analysis. Despite only 15% self-reporting (n=152/1016) a prior diagnosis of OSA, PSG data (subset n=505) showed 76% met the criteria for OSA. In terms of PSG-confirmed OSA severity, 35% had mild, 25% had moderate, and 15% had severe OSA. STOP-Bang (n=75) suggested that 49% were low risk, 55% were moderate risk and 16% were high risk for moderate-to-severe OSA. Using a WristOx (n=137) ODI cut-off of 5, 84% of participants were classified as having OSA. The STOP-Bang demonstrated low predictive validity for PSG-confirmed moderate-severe OSA (AUC=0.631, p=0.172). There was a significant moderate correlation between ODI from WristOx and PSG (rho=0.494, p=0.001). Bland-Altman plot demonstrated a mean difference between ODI obtained from WristOx and PSG of 0.84 (SD=11.6, with 95% limits of agreement from -21.9 to 23.6).
Conclusion
Although the primary concern for participants attending memory clinics is cognition, rates of OSA are high and appear to be severely underdiagnosed within this context. Unfortunately, while the STOP-Bang questionnaire has been validated for use in other clinical settings, the predictive validity for OSA in those attending a memory clinic appears to be low. Objective OSA screening tools (e.g., pulse oximetry) may be more beneficial.
Research Funding Source: The National Health and Medical Research Council (NHMRC) Centre of Research Excellence to Optimise Sleep in Brain Aging and Neurodegeneration (CogSleep CRE) (APP: 1152945); NHMRC Boosting Dementia Leadership (Fellowship No. 1135639 to S.L.N.
