Remote Monitoring in Obstructive Sleep Apnea

Prior to enrollment, patients were seen by a clinician at the Veterans Administration (VA) Hospital in West Haven, Connecticut. Either a facility-based diagnostic polysomnogram or unattended home sleep testing was performed at the evaluating clinician's discretion. Clinicians that saw the patient determined whether PAP therapy was needed, and either auto-titrating continuous positive airway pressure (CPAP) or set pressures of CPAP were ordered for the patient. Patients received education about OSA and about their equipment from a respiratory therapist and physician's assistant within the VA who then provided the equipment for them. Patients coming to this internal Durable Medical Equipment (DME) provider were screened for participation in the study.The study was overseen by the Institutional Review Board at the Veterans Affairs Connecticut Health Care in West Haven, Connecticut. Informed consent was obtained from all participants.

Patients were included in the study if they were diagnosed with OSA (defined as AHI or apnea-hypopnea index greater than five per hour with symptoms, or AHI greater than 15/hour), and if they were being exposed to PAP for the first time. Patients who were previously treated with PAP, had central apnea, chronic respiratory failure, recent in-patient hospital admissions (=< 2 weeks), or were living outside cellular network coverage area were excluded from the study.

Patients that met study inclusion criteria were provided ResMed S9 devices with wireless modems. Their usage and treatment data was tracked using EasyCare Online, a cloud-based system for the ResMed devices. After the initial setup and educational settings, the patients received supplies as needed and troubleshooting of side effects of treatment as needed. Devices were not removed after 3 months if they were not adherent.

Patients in the usual care group were monitored on a 3-month, 6-month, 9-month and 12-month intervals with scheduling face-to-face visits. Adherence and efficacy data were only assessed by the clinician at these intervals.

Patients in the wireless care group were monitored more frequently using wireless modems as the method to obtain adherence and efficacy data.

We then determined adherence using CMS (Centers for Medicare \& Medicaid Services) criteria at 3 months, and at 12 months. To obtain this data, we evaluated whether the PAP devices were used for 4 or more hours per night on 70% of nights during a consecutive 30-day period anytime during the first 3 months of initial use, and then a consecutive 30-day period in months 4-12. We also examined the daily use from the first to last day looking of overall patterns of utilization monthly, quarterly, semiannually and annually. Data was collected and maintained in a REDCap database (REDCap is a secure web application for building and managing online surveys and databases). Sensitivity and specificity calculations were then performed to evaluate predictability of adherence at 1 year using adherence at 3 months. Fisher's exact test was also used to evaluate the association between adherence at 3 months and 1 year and the association between AHI (Apnea -Hypopnea Index) and adherence.