Draft assessment questions impact of CPAP therapy

WASHINGTON – Published studies mostly do not support that CPAP therapy affects long-term, clinically important outcomes, according to a 155-page draft technology assessment prepared for the Agency for Healthcare Research and Quality at the U.S. Department of Health and Human Services. 

Specifically, with low strength of evidence, randomized controlled trials do not demonstrate that CPAP therapy affects all-cause mortality, various cardiovascular outcomes, changes in psychological measures or other clinically important outcomes, according to the assessment. 

“When nonrandomized comparative studies are combined with the randomized controlled trials, there is the suggestion that CPAP reduces the risks of all-cause mortality,” the assessment states. “Other conclusions are not changed. The low strength of evidence for these outcomes suggests that we have limited confidence that the summary estimates are close to the true effect.” 

CMS asked the AHRQ to evaluate the evidence on improvement of long-term clinical health outcomes with CPAP treatment, as well as the validity of criteria used as surrogate outcomes. 

The resulting systematic review evaluated: the variability across research studies in definitions of breathing measures and criteria to diagnose OSA; the effectiveness, comparative effectiveness and harms of CPAP use on long-term clinical significant outcomes; and the validity of AHI and similar measures as a surrogate or intermediate measure for clinically significant outcomes. 

“Additional studies are needed before we have a clear understanding of the potential effects of CPAP on long-term outcomes for patients with OSA, whether any particular group of patients may benefit to a greater or lesser degree from CPAP treatment or whether AHI (and/or other breathing measures) are valid intermediate or surrogate measures of clinical outcomes,” the assessment states.