Nearly 1 billion people worldwide have obstructive sleep apnea (OSA), a chronic disease that causes breathing to stop and start during sleep, often hundreds of times per night. If left untreated, sufferers are twice as likely to experience sudden death compared to people living without OSA, and are exposed to an increased risk of developing cardiovascular conditions such as hypertension, coronary artery disease, chronic heart failure and other comorbidities.
Continuous positive airway pressure (CPAP) is the gold standard in treatment of OSA. The relationship between CPAP’s effect on OSA and mortality has been difficult to study in randomized controlled trials (RCTs) due to ethical concerns about intentionally withholding CPAP. However, an emergence of real-world evidence has shown a more accurate and generalizable picture of the effects of routine clinical usage of CPAP on mortality.
CPAP Helps OSA Patients Live Longer
Using CPAP therapy as indicated can significantly increase OSA patients’ chances of living longer, according to a recently published study that builds upon the large collection of evidence demonstrating the long-term benefits of CPAP. The ResMed-sponsored ALASKA study, “CPAP Termination and All-Cause Mortality: a French Nationwide Database Analysis,” concluded that people with OSA who continued CPAP therapy were 39% more likely to survive than OSA patients who did not. The survival rate gap remained significant when accounting for patients’ ages, overall health, other pre-existing conditions and causes of death.
This survival benefit was observed from a sample size of more than 176,000 people in France with sleep apnea over a three-year period, a study population much larger than typically seen in RCTs. The analysis included data from all new CPAP users aged 18 or over extracted from the French national health insurance reimbursement system database (SNDS), one of the largest anonymized claims databases in the world, and representative of health spending reimbursements for more than 99% of the country’s population. In contrast to the highly selective and segmented population typically found in RCTs, this data source is representative of an entire national population and does not include biases in insurer or health care provider, offering a holistic view of clinical outcomes.
Unlocking the Growing Power of Real-World Data
This approach is an example of the power of using big data to produce real world evidence (RWE). Because all OSA patients in France with an indication for CPAP therapy were included, the results are generalizable to broader clinical populations and highlights the potential for ongoing usage of CPAP treatment to reduce all-cause mortality in patients with OSA.
The power of these studies made in the real world is being recognized by the U.S. Food and Drug Administration’s (FDA) embracing in regulatory decisions of the benefits of both pharmaceutical products and medical devices.
“The real-life clinical performance of a medical product might be more clearly demonstrated through real world data/RWE because a controlled clinical trial often cannot evaluate all applications of a product in clinical practice across the full range of potential users,” the FDA said.
Many other studies have recently added to a growing body of evidence for the beneficial effects of CPAP usage on OSA patient survival. A Japanese study found the all-cause mortality rate to be significantly lower in those who did versus did not use CPAP after a followup of six to seven years, and a study from the United Kingdom found that OSA patients treated with CPAP for more than five years were significantly more likely to be alive at the end of the study.
The Industry Must Consider RWE
The ALASKA study disputes the overarching conclusion of the draft technology assessment from the Agency for Health Research Quality (AHRQ), which asserts that there is sparse evidence regarding the long-term effectiveness of CPAP devices in treating OSA. With a disregard for RWE, the assessment predominately included RCTs as evidence, despite the studies having low adherence, which impacts their ability to demonstrate CPAP efficacy. The adherence was also lower than that currently seen with cloud-connected CPAP solutions that enable telemonitoring of OSA patients.
However, other governmental bodies are making encouraging developments in evidence-based medicine. After a significant and inclusive review of available evidence and patient outcomes related to CPAP, the U.K.’s National Institute for Health and Care Excellence (NICE) recently published guidance extending the use of CPAP as the first-line treatment for mild OSA patients (in addition to moderate to severe OSA patients), allowing more patients to access treatment. NICE also recommended telemonitoring for all OSA patients.
Clinical, physician and patient associations worldwide have rallied against the failure to recognize the long-term clinical, patient-centered benefits of CPAP. The American Academy of Sleep Medicine organized a multi-societal response to the AHRQ draft technical assessment, with global industry groups joining in to voice concern for the millions of patients who have benefited from the long-term treatment of their OSA and those yet to be diagnosed.
The ALASKA study concluded that people diagnosed with OSA who continued PAP therapy live longer, evidenced by the analysis of a non-biased, vast variety of patients with results applicable to a much broader patient population. Using big data to produce real world evidence, the findings provide a better indication of overall effectiveness in patient populations likely to be encountered in routine clinical practice. The final AHRQ technology assessment—as well as all future assessments—should include alternative methods for estimating treatment effects, such as those used in RWE studies, to complement the results seen in RCTs in order to provide further insight into the actual effects of these devices on patients’ lives.
