Targeted case finding for OSA within the primary care setting

FOUND Trial: randomised controlled trial study protocol for case finding of obstructive sleep apnoea in primary care using a novel device

INTRODUCTION

Obstructive sleep apnoea (OSA) is a common, but underdiagnosed, sleep disorder. If untreated, it leads to poor health outcomes, including Alzheimer's disease, cancer, cardiovascular disease and all-cause mortality. Our aim is to determine the feasibility and cost-effectiveness of moving the testing for OSA into general practice and how general practitioner (GP)-based screening affects overall detection rates.

METHODS AND ANALYSIS

Randomised controlled trial of case finding of OSA in general practice using a novel Medicines and Healthcare products Regulatory Agency-registered device (AcuPebble SA100) compared with usual care with internal feasibility phase. A diverse sample of general practices (approximately 40) from across the West Midlands Clinical Research Network will identify participants from their records. Eligible participants will be aged 50-70 years with body mass index >30 kg/m2 and diabetes (type 1 or 2) and/or hypertension (office blood pressure >145/90 mm Hg or on treatment). They will exclude individuals with known OSA or chronic obstructive pulmonary disease, or those they deem unable to take part. After eligibility screening, consent and baseline assessment, participants will be randomised to either the intervention or control group. Participants in the intervention arm will receive by post the AcuPebble sleep test kit. Those in the control arm will continue with usual care. Follow-up questionnaires will be completed at 6 months. The study is powered (90%) to detect a 5% difference and will require 606 patients in each arm (713 will be recruited to each arm to allow for attrition). Due to the nature of the intervention, participants and GPs will not be blinded to the allocation.

OUTCOMES

Primary: Detection rate of moderate-to-severe OSA in the intervention group versus control group. Secondary: Time to diagnosis and time to treatment for intervention versus control group for mild, moderate and severe OSA; cost-effectiveness analysis comparing the different testing pathways.

ETHICS AND DISSEMINATION

The trial started on 1 November 2022. Ethical approval was granted from the South Central Oxford A Research Ethics Committee on 9 June 2023 (23/SC/0188) (protocol amendment version 1.3; update with amendment and approval to renumber to V2.0 on 29 August 2023). Patient recruitment began on 7 January 2024; initial planned end date will be on 31 April 2025.Results will be uploaded to the ISRCTN register within 12 months of the end of the trial date, presented at conferences, submitted to peer-reviewed journals and distributed via our patient and public involvement networks.The University of Warwick will act as the trial sponsor. The trial will be conducted in accordance with the Sponsor and Primary Care Clinical Trials Unit standard operating procedures.

TRIAL REGISTRATION NUMBER

ISRCTN 16982033.

Obstructive Sleep Apnea and Its Cardiac Implications in the United States: An Age-Stratified Analysis Between Young and Older Adults

BACKGROUND

Obstructive sleep apnea (OSA) is a common sleep disorder associated with cardiovascular risks. This study aimed to assess the prevalence of probable OSA and its relationship with cardiovascular risks and diseases focusing on age-stratified young adults (20-40 years) and older (>40 years).

METHODS AND RESULTS

The study used a cross-sectional design, analyzing data from the National Health and Nutrition Examination Survey conducted between 2013 and 2018, comprising 9887 community-dwelling adults aged ≥20 years. Probable OSA was determined on the basis of self-report of OSA-related symptoms (eg, snoring, gasping/breath cessation while sleeping). Cardiovascular risk factors, including hypertension, diabetes, hyperlipidemia, and metabolic syndrome, were evaluated according to established guidelines. Cardiovascular diseases (CVDs) included self-reported heart conditions, including congestive heart failure, coronary heart disease, angina, heart attacks, and strokes. Individuals with probable OSA showed a significantly higher prevalence of health conditions, including hypertension (adjusted prevalence ratio [aPR], 1.19; P<0.001), diabetes (aPR, 1.17; P: 0.01), metabolic syndrome (aPR, 1.14; P<0.001), heart attack (aPR, 1.63; P<0.01), stroke (aPR, 1.41; P: 0.03), and any CVD event (aPR, 1.36; P: 0.01) after adjusting for relevant factors. Young adults with probable OSA showed higher prevalence rates of any CVD events (aPR, 3.44; P<0.001), hypertension (aPR, 1.45; P<0.001), metabolic syndrome (aPR, 1.25; P<0.001), and angina (aPR, 10.39; P<0.001).

CONCLUSIONS

The study suggests early identification and management of OSA in individuals at risk for CVD. While cross-sectional, it emphasizes that health care providers should recognize OSA as significantly associated with CVDs and its precursor risks in young adults, stressing proactive care and screening to reduce CVD risk in this population.

The prevalence of obstructive sleep apnea in patients with type 2 diabetes: a systematic review and meta-analysis

Background

Obstructive Sleep Apnea (OSA) is one of the diseases related to diabetes. Considering the varying prevalence of OSA in patients with type 2 diabetes in different parts of the world, in order to aggregate the results and come to a general review about the topic mentioned, the current study performed a systematic review and meta-analysis of OSA in patients with type 2 diabetes.

Methods

In this study, the international databases (PubMed, Scopus, Web of science, and Cochran library) were searched without time limit using keywords diabetes, obstructive sleep apnea, and prevalence or epidemiology. Homogeneity was investigated among studies using Cochran Q test and I2 index. Given the heterogeneity of studies, random effect model was used to estimate the prevalence of OSA. Meta-regression was used to investigate the effect of quantitative variables on the prevalence of OSA. Comprehensive Meta-analysis (CMA) software was used for data analysis.

Results

Twenty studies were included in the meta-analysis. In these 19 studies, the total number of patients with type 2 diabetes was 10,754, with a mean age of 58.6 ± 4.1 years. Final estimation of OSA prevalence was calculated to be 56.0%. The results of meta-regression showed the prevalence of OSA increased with a rise in the mean age, the percentage of male sex, body mass index, and sample size.

Conclusion

Given the high prevalence of OSA in patients with type 2 diabetes, weight control can partly mitigate their problems and possibly reduce OSA prevalence.

The effect of CPAP therapy on excessive daytime sleepiness and quality of life in subjects with obstructive sleep apnoea: an AB design study

BACKGROUND

Obstructive sleep apnoea (OSA) is a disorder characterized by apnoeas and hypopnoeas due to repetitive upper airway collapse during sleep. So far, there are no published data regarding quality of life (QoL) and adherence to CPAP among patients with OSA in India. This study aims to measure sleepiness and QoL of patients before and after effective CPAP use in patients with OSA.

METHOD

Newly diagnosed subjects with OSA were included, and socio-demographic risk factors and anthropomorphic measures were collected. Epworth sleepiness scale (ESS) and short sleep apnoea quality of life index (SAQLI) were administered before and after a minimum of 4 weeks of domiciliary CPAP use. While short SAQLI is a disease-specific questionnaire, ESS measures excessive daytime sleepiness.

RESULTS

In 92 subjects age range was 28-74 years, mean age 49.7 ± 11.3 years, and male:female ratio was 70:22. Mean BMI was 32.1 ± 6.4 kg/sq.m; mean neck circumference was 39.4 ± 3.4 cm; 56 subjects had Mallampati score of 3 or 4. One-month follow-up was completed by 34 subjects who reported a mean of 5.8 ± 1.1 hours/night usage of CPAP. Mean ESS score was 11.31 ± 5.6 at baseline vs 6.9 ± 3.3 after 1 month (p = 0.02), and baseline short SAQLI score was at 2.54 ± 1.26 vs 1.38 ± 0.87 after 1 month (p = 0.0001).

CONCLUSIONS

Subjects reported adequate compliance with CPAP at 1 month, and both ESS and short SAQLI showed a significant improvement in these patients. CPAP compliance improved both QoL and sleepiness in patients with OSA.

Obstructive Sleep Apnea in a rural population in South India: Feasibility of health care workers to administer level III sleep study

Objectives:

To estimate the occurrence of obstructive sleep apnea (OSA) and its risk factors in a rural Indian population using screening questionnaire and Level III sleep study. To determine the feasibility to train community health workers to administer Level III sleep study in the high-risk population.

Materials and Methods:

The study was conducted from seven villages with adult population of 2247, in Mugalur, near Bengaluru, from January to April 2014. Berlin questionnaire was used to screen 321 participants chosen by stratified random sampling. A total of 26 out of 321 patients underwent Level III sleep study at home, administered by the health workers, who were trained in three sessions to hook up the machine. Data were verified by a certified sleep physician.

Results:

The mean age was 39.43 ± 15.6 years with the M:F ratio of 0.98:1. Prevalence of risk of OSA by Berlin questionnaire was 8.72% (95% confidence interval [CI] 5.63, 11.81) in the total population, 7.4% in males and 11.7% in females. Older age (odds ratio [OR] 3.97; CI 1.63, 9.6), hypertension (OR 11; CI 4.3, 28.2), obesity (OR 2.35; CI 1, 5.5), and higher Mallampati score (OR 3.78; CI 1.7, 8.4) were significantly associated with high risk of OSA (P = 0.0001–0.04). Twenty-six patients underwent Level III sleep study and OSA was diagnosed in 12 patients. The mean apnea–hypopnea index (AHI) of this group was 9.7/h. The prevalence of OSA by AHI criteria was 3.74%.

Conclusions:

OSA is underdiagnosed in rural populations, although risk factors are present. Training community health workers to administer Level III sleep study is a feasible and cost-effective strategy.

Type III home sleep testing versus pulse oximetry: is the respiratory disturbance index better than the oxygen desaturation index to predict the apnoea-hypopnoea index measured during laboratory polysomnography?

OBJECTIVES

In its guidelines on the use of portable monitors to diagnose obstructive sleep apnoea, the American Academy of Sleep Medicine endorses home polygraphy with type III devices recording at a minimum airflow the respiratory effort and pulse oximetry, but advises against simple pulse oximetry. However, oximetry is widely available and simple to use in the home. This study was designed to compare the ability of the oxygen desaturation index (ODI) based on oximetry alone with a stand-alone pulse oximeter (SPO) and from the oximetry channel of the ApneaLink Plus (ALP), with the respiratory disturbance index (RDI) based on four channels from the ALP to predict the apnoea-hypopnoea index (AHI) from laboratory polysomnography.

DESIGN

Cross-sectional diagnostic accuracy study.

SETTING

Sleep medicine practice of a multispecialty clinic.

PARTICIPANTS

Patients referred for laboratory polysomnography with suspected sleep apnoea. We enrolled 135 participants with 123 attempting the home sleep testing and 73 having at least 4 hours of satisfactory data from SPO and ALP.

INTERVENTIONS

Participants had home testing performed simultaneously with both a SPO and an ALP. The 2 oximeter probes were worn on different fingers of the same hand. The ODI for the SPO was calculated using Profox software (ODI(SOX)). For the ALP, RDI and ODI were calculated using both technician scoring (RDI(MAN) and ODI(MAN)) and the ALP computer scoring (RDI(RAW) and ODI(RAW)).

RESULTS

The receiver-operator characteristic areas under the curve for AHI ≥ 5 were RDI(MAN) 0.88 (95% confidence limits 0.81-0.96), RDI(RAW) 0.86 (0.76-0.94), ODI(MAN) 0.86 (0.77-0.95), ODI(RAW) 0.84 (0.75-0.93) and ODI(SOX) 0.83 (0.73-0.93).

CONCLUSIONS

We conclude that the RDI and the ODI, measured at home on the same night, give similar predictions of the laboratory AHI, measured on a different night. The differences between the two methods are small compared with the reported night-to-night variation of the AHI.

A Comprehensive Evaluation of a Two-Channel Portable Monitor to "Rule in" Obstructive Sleep Apnea

STUDY OBJECTIVES

We hypothesized that a dual-channel portable monitor (PM) device could accurately identify patients who have a high pretest probability of obstructive sleep apnea (OSA), and we evaluated factors that may contribute to variability between PM and polysomnography (PSG) results.

METHODS

Consecutive clinic patients (N = 104) with possible OSA completed a home PM study, a PM study simultaneous with laboratory PSG, and a second home PM study. Uniform data analysis methods were applied to both PM and PSG data. Primary outcomes of interest were the positive likelihood ratio (LR+) and sensitivity of the PM device to "rule-in" OSA, defined as an apnea-hypopnea index (AHI) ≥ 5 events/h on PSG. Effects of different test environment and study nights, and order of study and analysis methods (manual compared to automated) on PM diagnostic accuracy were assessed.

RESULTS

The PM has adequate LR+ (4.8), sensitivity (80%), and specificity (83%) for detecting OSA in the unattended home setting when benchmarked against laboratory PSG, with better LR+ (> 5) and specificity (100%) and unchanged sensitivity (80%) in the simultaneous laboratory comparison. There were no significant night-night (all p > 0.10) or study order effects (home or laboratory first, p = 0.08) on AHI measures. Manual PM data review improved case finding accuracy, although this was not statistically significant (all p > 0.07). Misclassification was more frequent where OSA was mild.

CONCLUSIONS

Overall performance of the PM device is consistent with current recommended criteria for an "acceptable" device to confidently "rule-in" OSA (AHI ≥ 5 events/h) in a high pretest probability clinic population. Our data support the utility of simple two-channel diagnostic devices to confirm the diagnosis of OSA in the home environment.

COMMENTARY

A commentary on this article appears in this issue on page 411.