# Early Screening of Sleep-Disordered Breathing Using a Smartphone-Based Portable System in Stroke Patients and Its Relevance for Rehabilitation: A Prospective Observational Study

## TL;DR

A smartphone-based system detected undiagnosed sleep apnea in stroke patients, which is linked to worse recovery outcomes and could help improve rehabilitation.

## Contribution

A smartphone-based system for early detection of sleep apnea in stroke patients was evaluated and shown to be effective and easy to use.

## Key findings

- Most post-stroke patients had previously undiagnosed sleep apnea detected via smartphone-based monitoring.
- Greater sleep-disordered breathing and hypoxemia were linked to worse baseline disability and lower rehabilitation outcomes.

## Abstract

What are the main findings?
The smartphone-based portable monitoring system enabled detection of previously undiagnosed sleep apnea among post-stroke patients undergoing rehabilitation.Greater sleep-disordered respiratory events and nocturnal hypoxemia were associated with worse baseline disability and lower rehabilitation metrics.

The smartphone-based portable monitoring system enabled detection of previously undiagnosed sleep apnea among post-stroke patients undergoing rehabilitation.

Greater sleep-disordered respiratory events and nocturnal hypoxemia were associated with worse baseline disability and lower rehabilitation metrics.

What are the implications of the main findings?
The portable system was easy to use, facilitating sleep apnea detection after stroke and supporting broader implementation in rehabilitation settings.Routine screening for sleep-disordered breathing at admission may enable earlier diagnosis and management in patients with substantial hypoxemia/event burden that could slow functional recovery.

The portable system was easy to use, facilitating sleep apnea detection after stroke and supporting broader implementation in rehabilitation settings.

Routine screening for sleep-disordered breathing at admission may enable earlier diagnosis and management in patients with substantial hypoxemia/event burden that could slow functional recovery.

Sleep-disordered breathing (SDB) is common after stroke and may negatively influence recovery, yet it is frequently underdiagnosed. Portable respiratory monitoring devices could facilitate early SDB screening in these patients. We estimated the prevalence of sleep apnea (SA) using a smartphone-based monitoring system in post-stroke patients and examined associations between respiratory indices, stroke severity and disability (NIHSS, mRS), and rehabilitation outcomes (motor and cognitive Functional Independence Measure; FIM). Consecutive patients admitted to inpatient rehabilitation within three months after a stroke underwent an overnight assessment with a smartphone-based respiratory monitoring device, which estimated the apnea–hypopnea index (AHI), mean and minimum SpO2, time with SpO2 < 94% and <90%, and hourly oxygen desaturation events (≥3% and ≥4%). Of the 104 screened patients, 59 were recruited, while 56 had valid recordings. Most patients (89%) had previously undiagnosed SA: 11% mild (AHI ≥ 5 and <15), 38% moderate (AHI ≥ 15 and <30), and 41% severe (AHI ≥ 30). Greater event burden and nocturnal hypoxemia were associated with older age, worse baseline disability (mRS), lower admission motor FIMs, and poorer rehabilitation metrics. Smartphone-based portable monitoring is an accessible, easy-to-use approach that may enable earlier identification of SA, particularly in individuals with substantial hypoxemia or respiratory event burden.