Obstructive sleep apnea (OSA) is a type of sleep-related breathing disorders that is characterized by a sleep-related constriction (obstruction) of the upper airways. The treatment with continuous application of positive airway pressure (CPAP) via respiratory mask forms the therapeutical standard of OSA. The autoCPAP (automatic positive airway pressure: APAP) therapy is an additional treatment option for patients with more unstable conditions (e.g. due to sleep position) which is characterized by a dynamic adaption of the applied airway pressure according to patients therapeutical needs. Device usage time and therapy adherence are crucial for treatment success.

The purpose of this study is to assess the effect of a digital patient support (DPS) tool, complementary to standard care on continuous and automatic positive airway pressure (CPAP, APAP) adherence and daytime sleepiness after 12 weeks in patients diagnosed with severe obstructive sleep apnea (OSA).

All patients with apnea-hypopnea index (AHI) ≥ 30 per hour are prospectively included and randomized to receive standard care (SC) or standard care with personalized DPS via prisma APP prototype version (SC+DPS). In both arms, initiation of therapy and standardized therapy control after 12 weeks is carried out identically. Patients in the SC+DPS arm received additionally automated feedback on their therapy and motivational messages, as well as therapy recommendations.

Clinical Picture From the epidemiological view obstructive sleep apnea (OSA) is the most common type of sleep-related breathing disorders (SRBD). OSA is characterized by a sleep-related constriction (obstruction) of the upper airways that in adulthood is often caused by a neuromuscular related impairment of the pharyngeal tone. OSA is linked to many negative health consequences and is associated with a large number of comorbidities.

General treatment As a rule SRBD are treated with appropriate therapy devices that transmit positive airway pressure (PAP) via respiratory masks. In the case of the treatment of obstructive sleep apnea (OSA) therapeutical standard is formed by application of continuous positive airway pressure (CPAP). CPAP therapy devices provide a stable positive airway pressure during sleep to prevent the upper airway obstructions. The determination of the essential airway pressure that keeps airways open takes place within the therapy setting night in the sleep laboratory under polysomnographic monitoring. Patients with more unstable pressure needs, e.g. based on position shifts during the night, also qualify for an autoCPAP (APAP) therapy. APAP therapy devices adapt the applied airway pressure dynamically within defined ranges according to patients' therapeutical needs. Therapy success is essentially defined by average device usage time and patients' long-term therapy adherence which in term is affected by a broad variety of factors. The identification of these factors therefore lead to the development of different treatment strategies to improve patients' therapy adherence.

Usual therapeutical process Patients with suspected OSA are surveyed according to their symptomatology and receive a sleep medical examination under polygraphical or polysomnographical observation. During the sleep medical examination numerous cardiorespiratory and somnological signals are recorded and evaluated.

As far as the evaluation of the recorded signals leads to the diagnosis of OSA and no indications for another type of PAP therapy are present, the adjustment to CPAP or APAP therapy under polysomnographical observation takes place immediately after diagnosis.

Following this, patients receive an appropriate adjusted CPAP- or APAP therapy device and get introduced in it´s handling to continue therapy by themselves in their home environment.

As part of the nightly home therapy, patients are expected to use the device according to the physicians advice. During the home therapy phase, the device is recording specific data to subsequently allow to draw conclusions about the therapeutic process and the therapy quality. In case of difficulties with therapy and dependent on their causes, patients are admonished to contact the sleep laboratory (regarding general problems with therapy) or the provider (regarding problems with the respiratory mask or device settings).

After a period of about 12 weeks, patients again appear in person in the sleep laboratory as part of the general therapy control. During the therapy control, the home usage data recorded by the therapy device are printed in reportform and the interventions which were implemented between first therapy setting and the therapy control are evaluated.

Finally, the medicating physician evaluates the therapy success within a conversation with the patients. In case of an inadequate outcome, therapy settings may have to be optimized.

Rationale of the study Literature shows that the first days of home therapy are crucial for long-term therapy adherence and that telemetrical support through automatic feedback can have a positive effect on therapy adherence.

However, there is a lack of experience how the effect on therapy outcomes caused by more individualized, automatic feedbacks combined with an appropriate supply of information and motivation over a longer period can be assessed.

This study is intended to investigate if therapy outcomes of CPAP and APAP patients can be further improved by an early intervention in the form of a combination of telemetric and electronic support.

Description of the applied medical device The applied medical device are the CE certified medical devices prismaSOFT/ prismaSMART (Type WM090TD) made by Löwenstein Medical Techology GmbH und Co. KG Hamburg. The applied accessories (especially breathing tubes, masks, humidifier, modems) are CE certified, too.

Devices of the WM090TD type are pressure-controlled, non-invasive, non-lifesupporting therapy devices or treating sleep-related breathing disorders (SRBDs) using a mask. The devices are used on persons weighing 30 kg or more. CPAP mode can be used on persons aged 3 years upwards. The device may only be used on a physician's instructions. (auto)CPAP mode provides positive airway pressure for treating obstructive sleep apnea in patients who breathe spontaneously.

Devices of the WM090TD type are used in clinical facilities and in the domestic environment. In the domestic environment, the devices also ac-company the owner on trips away.

The application of the device as part of this study takes place according to it´s intended use and within it´s indication range.

Procedure and interventions

If an OSA was diagnosed, patients will be asked for study participation and get informed about the rationale of the study. In case of patients informed consent they will be randomized to one of two groups (Standard Care = control group vs. Standard Care + Digital Patient Support Tool = intervention group).

At baseline, all patients receive an education session with a respiratory therapist about OSA and its consequences, proper use and maintenance of the CPAP device and mask, and therapy and study expectations. All patients are provided with a fixed or auto CPAP device (prismaSMART/ prismaSOFT, Löwenstein Medical Technology GmbH & Co. KG), a heated humidifier (prismaAQUA, Löwenstein Medical Technology GmbH & Co. KG) if needed, and a fitting interface. The initiation of therapy with anamnesis, diagnosis night, titration night, education, etc., as well as standardized therapy control after 12 weeks is carried out identically in standard care (SC) and in standard care with personalized digital support via prototype of prisma APP (SC+DPS) group and according to clinical routine.

At the beginning and with completion of the study every participant is surveyed about his daytime sleepiness applying the standardized questionnaire "Epworth Sleepiness Scale (ESS)".

With completion of the study, each patient furthermore assesses his satisfaction with the CPAP therapy in general and with focus on therapy instructions and support. For this purpose, they rate 8 questions on a scale of 0-4, with a 4 being the best rating (0: strongly disagree, 1: barely disagree, 2: partly agree, 3: mostly agree, 4: strongly agree).

The intervention (SC+DPS) group receives electronic therapy support in addition to standard care. The electronic therapy support consists of:

1. Emails to patients with personalized, automated feedback on their therapy (derived from device data received via modem or data entered by the patient via electronic questionnaire),
2. electronic questionnaires (web-based) on possible problems during therapy and subjective therapy success,
3. possibility to set personal adherence goals every week,
4. links to explanations and videos on therapy and the handling of therapy equipment and accessories,
5. provision of data for the trial center in the event of contact by the patient, as well as for routine therapy monitoring.

Inclusion Criteria:

• age 18-80 years
• CPAP-naïve
• confirmed severe OSA (AHI >30/h), diagnosis based on polysomnography (PSG) (MiniScreen PRO with Software MiniscreenViewer, Dr. Fenyves & Gut, Rangendingen, Germany)
• written informed consent to participate in the study, including a data protection statement.

Exclusion Criteria:

• presence of a contraindication to PAP therapy
• participation in another study influencing automated electronic support
• lack of possibility to receive emails or use electronic means of communication
• lack of patient consent.