A new two-stage screening model for obstructive sleep apnea (OSA) in primary care settings, combining the STOP-BANG questionnaire (SBQ) with automated home sleep apnea testing (HSAT), shows promise for improving detection rates and reducing unnecessary referrals. The study, conducted in Slovenia, highlights the potential of this approach to streamline OSA diagnosis in primary care, where resources and expertise may be limited.
Automated HSAT Scoring: A Reliable Alternative
The research team evaluated the accuracy of automated scoring of HSAT recordings compared to manual scoring by a somnologist. Results indicated a strong correlation between the two methods (Pearson's r = 0.926, p < 0.001). Although automated scoring slightly overestimated the respiratory event index (REI) by an average of 1.6 events per hour, the interrater reliability for OSA diagnosis was excellent (Cohen's kappa = 0.80).
"The slightly higher REI from automated scoring could misclassify some borderline cases as mild OSA. However, this is of limited clinical relevance," the authors noted, emphasizing that asymptomatic mild OSA patients typically do not require immediate CPAP therapy.
Two-Stage Screening Model: Enhanced Diagnostic Performance
The study assessed a two-stage model where patients with an SBQ score of 3 or higher underwent automated HSAT. A positive screening result was defined as an automated REI of 5 or higher. This model demonstrated a sensitivity of 64%, a specificity of 97.4%, and an accuracy of 81.1% for detecting any OSA (REI ≥ 5).
Compared to using the SBQ questionnaire alone, the two-stage model improved specificity without significantly sacrificing sensitivity. Specifically, the two-stage model had a Cohen's kappa of 0.62, a sensitivity of 0.64, a specificity of 0.97, and an accuracy of 0.81, outperforming the Slovenian SBQ questionnaire alone (sensitivity 0.65, specificity 0.87).
Implications for Primary Care
The findings suggest that incorporating automated HSAT scoring into primary care practices could enhance the efficiency and accuracy of OSA screening. By reducing the reliance on manual scoring and specialist interpretation, this approach could facilitate earlier diagnosis and treatment initiation for patients at risk of OSA.
"To the best of our knowledge this is the first time a two-stage screening for OSA in the family practice setting, using type 3 PG, was performed," the researchers stated. They estimate that implementing the two-stage model could decrease referrals for sleep studies by 15.3%, potentially alleviating the burden on sleep clinics and reducing healthcare costs.
Study Details and Limitations
The cross-sectional study involved 153 adult patients (aged 18-70 years) recruited from four family practices in Slovenia. Participants completed the SBQ and underwent HSAT using the Alice NightOne device (Phillips Respironics). Automated scoring was performed using Sleepware G3 software, and manual scoring served as the reference standard.
The authors acknowledged several limitations, including the restriction of participant age, the prolonged recruitment period due to the COVID-19 pandemic, and the use of type 3 PG with manual scoring instead of type 1 PSG. However, they emphasized that the chosen methodology aligned with standard clinical practice and available resources.
Despite these limitations, the study provides valuable insights into the potential of automated HSAT scoring and two-stage screening models to improve OSA detection in primary care. Further research is warranted to validate these findings in larger and more diverse populations.
