Wide vs. Narrow Pressure Ranges (APAP)

I finally got a copy of the study that launched this thread ( h/t dataq1 by PM)

Very interesting documentation.
A group 76 of previously untreated OSAS patients (AHI ~35) were treated with Resmed S-9 APAP machines
The 76 were randomly grouped into two cohorts:
The members of cohort A were setup for auto pressure range 8 cm to 12 cm (referred to as the low-span cohort)
The members of cohort B were setup for auto pressure range 4 cm -15 cm (referred to as high-span cohort)

After 1 month on treatment the AHI for cohort A and B insignificant (reduced from ~35 to ~ 2)
After 3 months on treatment the AHI for Cohort A was 1.7, while the AHI for cohort B 2.1, again not significant)

What was significant was the compliance;
In the high-span (cohort B) compliance fell significantly. only 67% of the original cohort were still compliant*
While in the low span (cohort A), 88.9% of the original cohort were still compliant.

Prevalent side effects are best shown by a chart from the study:
*compliance defined as usage for >4 hour per night at least 70% of the time.