Summary of the included studies
| Study (year, country) | Study design and overall RoB | Number of participants (n=1823) | Population description | Intervention | Intensity and duration | Mode of delivery | Main findings |
| Taylor et al. [22] (2006, USA) | RCT FU: 30 days High RoB | Total: 114 VC: 56 IP: 58 | Adult patients with OSA who were initiating CPAP therapy | Telemonitoring via the Health Buddy. OSA patients with “high-risk” responses were contacted within 24 h. | Patients were contacted as needed to resolve issues | Telephone consultation | ESS was not reported for post-intervention follow-up |
| Stepnowsky et al. [23] (2007, USA) | RCT FU: 2 months Moderate RoB | Total: 45 VC: 24 IP: 21 | Adult patients newly diagnosed with OSA | Telemonitoring via flow generator data. Objective and subjective patient reports triggered patient contact. | Patients were contacted as needed based on a pre-defined clinical pathway | Telephone consultation | No significant differences in ESS scores between the study groups at baseline and post-intervention |
| Isetta et al. [24] (2015, Spain) | RCT FU: 6 months Moderate RoB | Total: 139 VC: 69 IP: 70 | Adult OSA patients requiring CPAP treatment | Telemonitoring via a website developed for this study. Input evaluation triggered patient contact. | Virtual consultations via Skype were scheduled at 1 and 3 months. Consultation duration: 38.97±12.04 min. | Video consultation | Improvement in ESS at 6 months, but no significant difference in change from baseline between the study groups. The telemedicine-based strategy had a lower total cost compared to standard care. |
| Frasnelli et al. [26] (2015, Switzerland) | CCT FU: 30 days High RoB | Total: 223 VC: 113 IP: 110 | Adult patients with sleep apnoea | Telemonitoring via CPAP. A colour-coded algorithm triggered patient contact. | Patients were contacted as needed for a duration of ∼30 min | Telephone consultation | ESS was not reported for post-intervention follow-up |
| Fields et al. [25] (2016, USA) | RCT FU: 3 months Moderate to high RoB | Total: 60 VC: 32 IP: 28 | Adult patients with OSA from two community-based outpatient centres | Telemonitoring via APAP. Scheduled follow-up contact and if needed. | Initial evaluation visit for 40 min with a 10 min (or less) follow-up call at week 1. Virtual consultations scheduled at 1 and 3 months for 20 min each. | Initial evaluation via real-time CVT. Telephone consultation for follow-up. | No significant difference in the change of ESS scores from baseline to 3 months follow-up between the study groups |
| Turino et al. [27] (2016, Spain) | RCT FU: 1 and 3 months Moderate RoB | Total: 100 VC: 52 IP: 48 | Adult patients with newly diagnosed OSA requiring treatment with CPAP | Telemonitoring via MyOSA – Oxigen Salud web database. Automatic alarms triggered patient contact. | Patients were contacted as needed to resolve issues | Telephone consultation | ESS was not reported for post-intervention follow-up. The total average cost per randomised patient was 28% lower in the VC group than in the IP standard care group. |
| Lugo et al. [28] (2019, Spain) | RCT FU: 3 months Moderate RoB | Total: 186 VC: 94 (32 with CPAP) IP: 92 (40 with CPAP) | Adult patients with suspected OSA who were referred to the sleep unit | Telemonitoring via CPAP. Input in a custom web application triggered patient contact. | Virtual consultations were scheduled at 3, 6 and 12 weeks for no more than 15 min each | Video or telephone consultation | No significant differences in the ESS scores between the study groups. The costs of the VC were cheaper than those for IP standard care and the Bayesian analysis showed that the VC was cost-effective. |
| Nilius et al. [29] (2019, Germany) | RCT FU: 6 months Moderate to high RoB | Total: 80 VC: 40 IP: 40 | Adult OSA patients who had suffered an ischaemic stroke within the last 3 months | Telemonitoring. A colour-coded algorithm triggered a more detailed evaluation and patient contact if needed. | Patients were contacted as needed for a duration of 5 min | Telephone consultation | VC group had a significantly lower ESS scores at 6 months follow-up |
| Pépin et al. [30] (2019, France) | RCT FU: 6 months Moderate RoB | Total: 306 VC: 157 IP: 149 | Adult patients with severe OSA and high cardiovascular risk | Telemonitoring via CPAP and the multimodal system. Automatic algorithms triggered patient contact. | Patients were contacted as needed. Regular assessments at day 8 and months 1 and 6. | Telephone or teleconsultation | ESS scores significantly improved in both study groups, but the size of improvement was significantly higher in the VC group |
| Tamisier et al. [31] (2020, France) | RCT FU: 6 months Moderate RoB | Total:206 VC: 102 IP: 104 | Newly diagnosed adult patients with OSA and low cardiovascular risk who were referred for CPAP therapy | Telemonitoring via CPAP and the multimodal system. Automatic algorithms triggered patient contact. | Patients were contacted as needed based on an automatic algorithm | Telephone or teleconsultation | ESS scores significantly improved in both study groups, with no significant difference between the groups |
| Fietze et al. [33] (2021, Germany) | RCT FU: 6 months Moderate to high RoB | Total: 224 VC: 110 IP: 114 | Adult patients with moderate to severe OSA | Telemonitoring via APAP. Pre-defined criteria triggered patient contact. | Patients were contacted as needed based on pre-defined criteria | Telephone consultation | Change from baseline to 6 months in ESS scores was not significantly different between the two groups |
| Kooij et al. [32] (2021, Netherlands) | RCT FU: 4 weeks, 12 weeks, 24 weeks Moderate RoB | Total: 140 VC: 70 IP: 70 | Adult patients diagnosed with moderate or severe OSA who require CPAP treatment | Telemonitoring. Not achieving pre-defined objectives (e.g. adherence and residual AHI) triggered patient contact. | Patients were contacted as needed Scheduled follow-ups at 1 and 4 weeks | Video and telephone consultation | ESS was not reported for post-intervention follow-up |
AHI: apnoea–hypopnoea index; APAP: automatically adjusting positive airway pressure; CCT: controlled clinical trial; CPAP: continuous positive airway pressure; CVT: clinical video tele-health; ESS: Epworth Sleepiness Scale; FU: follow-up duration; IP: in person; OSA: obstructive sleep apnoea; RCT: randomised controlled trial; RoB: risk of bias; VC: virtual consultation.