The POSA Trial - Positional Therapy for Positional OSA

Apnoea-hypopnea Index (AHI) (events/hour) measured by overnight polygraphy; 0 to <5 events/hour is no OSA, >=5 to <15 events/hour is mild OSA, >=15to <30 events/hour is moderate OSA, >=30 events/hour is severe OSA; Lower AHI is an improvement in disease

Epworth Sleepiness Scale; 8 scenarios with the likeliness of falling asleep scored in each scenario from 0-3. The 8 Likert response items are summed to calculate a total score. Score range is 0 -24, with higher scores indicating greater daytime sleepiness. Scores >=11 are generally considered abnormal, or positive for excessive daytime sleepiness (EDS).

Functional Outcomes of Sleep Questionnaire (FOSQ) contains 30 items with 5 subscales (scored from 0-4 or 0-6 each). an average score is calculated for each subscale, and the 5 subscales are totaled to produce a total score.Score range is 5-20 points, with higher scores indicating better functional status.

The Hospital Anxiety and Depression Scale (HADS) is a fourteen item scale. Seven of the items relate to anxiety and seven relate to depression. Each item on the questionnaire is scored from 0-3 and this means that a person can score between 0 and 21 for either anxiety or depression. Scores of 8-10 indicate mild disease; 11-14 moderate and 15 to 21 severe. A reduction is considered an improvement in Anxiety or Depression.

The Townsend disability scale (McGee et al., 1998) is a short index of activities that assesses physical ability in social terms. The scale consists of nine questions or 'items'. The valid responses - 'yes, with no difficulty', 'yes, with some difficulty' and 'no, needs help'-score 0, 1 and 2 respectively. The scale gives equal weighting to each item. Townsend formed groups to interpret the scale (Townsend, 1979): a total score of 0 was regarded as indicating no disability, 1-2 being slightly affected, 3-6 having some disability, 7-10 having appreciable disability, 11-14 having severe disability and 15-18 having very severe disability.

The SF-36 questionnaire has 36 items dividing into 8 scales and then again into 2 components (mental and physical). The SF-36 consists of 8 scaled scores, which are the weighted sums of the questions in their section. Each scale is directly transformed into a 0-100 scale on the assumption that each question carries equal weight. The lower the score the more disability. The higher the score the less disability i.e., a score of zero is equivalent to maximum disability and a score of 100 is equivalent to no disability. To calculate the scores it is necessary to purchase special software. Sores out of 100 are presented for the 8 scales and 2 components

Pittsburgh Sleep Quality Index (PSQI): 19 items across 7 components are included in scoring. 5 additional items, to be completed by a bed partner, are included in the questionnaire but are not used for scoring. Each of the 7 component scores is determined based on scoring algorithms, with the 7 component scores each yielding a score of 0 -3. A PSQI global (total) score is obtained by summing each of the 7 component scores. Scoring algorithms for each component involve a mixture of averaging Likert response scores, categorization of free text responses (e.g., sleep latency of 15-30 minutes = 1 point), and arithmetic determination of sleep efficiency based on free-text responses. Score range is 0 -21 points, with higher scores indicating better sleep quality.

• Final scores after 3 months (adjusted for baseline scores) of patients treated with Positional Therapy, compared to sham-treated controls, in Healthcare Utilisation Questionnaire

• Visual analogue scale (VAS) of comfort and tolerance of device. The scale is a 100mm line with 0 representing low comfort and tolerance and 100 representing high comfort and tolerance

• Adherence to positional therapy measured by the Night Shift device will be reported as mean hrs/night over the entire 3 months. Good adherence for other OSA therapies, including CPAP, is suggested by an arbitrary threshold over >4 hours/night.

• A change from baseline to 3 months post Positional Therapy, compared to sham-treated controls NightShift data:
• percentage supine sleep compared to total sleep time (in previous populations, a reduction of supine sleep time by 84% is a good outcome)

A reduction in the supine sleep is an improvement

• A change from baseline to 3 months post Positional Therapy, compared to sham-treated controls, in oxygenation measured by:

-oxygen desaturation index (ODI; events/hour); measured by the number of overnight desaturations >3% and >4% as an index per hour An improvement is indicated by a reduction in ODI (normal is <5 events/hr)