Patients with moderate OSA according to a baseline nocturnal respiratory registration (NRR). Patients receive the same instructions and advice as in Arm "lifestyle advice" and also get a CC and instructions on how to sleep with it. CC is marketed for indications of various diseases such as traumatic cervical injury, cervical disc herniation and other neck problems and allows adjustment of the elevation level to achieve sufficient effect, i.e., extending the neck.Patients fill in questionnaire 1 that includes questions about nocturnal respiratory disturbances, daytime sleepiness, insomnia, use of tobacco and alcohol, comorbidity and medication. After 6+/-2 weeks of treatment, patients fill in Questionnaire 2 which contains the same questions as Questionnaire 1 and also questions about any side effects, evaluation of treatment. In conjunction with visit 2 another NRR will be performed.

Sleeping in the supine position is increased risk factor that contribute to development of OSA. This variable is recorded by Nocturnal Respiratory Registration (NRR).

OSA cause decrease of oxygen saturation in blood. This variable is recorded by pulse oximeter. Normal pulse oximeter readings usually range from 95 to 100 percent.

A number of desaturations more than 3% from baseline during sleep divided by number of sleeping hours.This variable is recorded by pulse oximeter.

It is important för assessing the difference between treatment methods. This variable is recorded by pulse oximeter.

It is important for assessing the difference between treatment methods. This variable is recorded by NRR.

It is important for assessing the difference between treatment methods. This variable is recorded by NRR.

Short Form Health Survey (SF36) taps eight health concepts: physical functioning, bodily pain, role limitations due to physical health problems, role limitations due to personal or emotional problems, emotional well-being, social functioning, energy/fatigue, and general health perceptions. Scoring is a two-step process. First, precoded numeric values are recorded per the scoring key given in Table 1. All items are scored so that a high score defines a more favorable health state. Each item is scored on a 0 to 100 range so that the lowest and highest possible scores are 0 and 100, respectively. Scores represent the percentage of total possible score achieved. In step 2, items in the same scale are averaged together to create the 8 scale scores. Table 2 lists the items averaged together to create each scale. Hence, scale scores represent the average for all items in the scale that the respondent answered.

Basic Nordic Sleep Questionnaire (BNSQ) consists of 27 items in 21 different questions and queries a wide range of sleep complaints, including difficulties initiating and maintaining sleep, subjective sleep quality, the use of medication to induce sleep, excessive daytime sleepiness, napping, snoring, and general sleep habits.Sleepiness scores range from 4 to 20 points, insomnia scores from 7 to 35, the higher scores indicating more problems with sleepiness or insomnia.

Epworth Sleepiness Scale (ESS) measures a respondent's general level of daytime sleepiness, or their average sleep propensity in daily life.It is a self-administered questionnaire with 8 questions. Respondents are asked to rate, on a 4-point scale (0-3), their usual chances of dozing off or falling asleep while engaged in eight different activities. The ESS score (the sum of 8 item scores, 0-3) can range from 0 to 24. The higher the ESS score, the higher that person's average sleep propensity in daily life.

It is important for assessing the patient's perception of treatment with CC. This variable is only recorded in experimental arm. There are three simple questions that respondent's should answer:

"How do you experience treatment in general?" (range very good - very bad), "Do you want to continue with the treatment?" ( yes or no) and "Own comments about the treatment".