Better adherence to positive airway pressure in OSA leads to lower healthcare costs

December 18, 2023

4 minutes of reading

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Key takeaways:

  • Average healthcare costs decreased with long-term and consistent use of positive airway pressure.
  • There was a difference of $832 in 6-month health care costs between those with high and low adherence.

According to the results published in CHEST.

Dennis Huang

“Although this study was a retrospective analysis and therefore we cannot prove a causal relationship between PAP adherence and lower health care utilization and costs, the potential causal relationship makes conceptual sense,” Dennis Huang, Ph.D., director of sleep medicine at Kaiser Permanente, told Healio. “Other research we’ve done shows a 70% higher rate of acute cardiovascular events (ie, heart attack and stroke) in patients with at least moderately severe OSA, but a 53% lower rate in those using PAP at least 4 hours a night. These results add up in promoting a narrative about the importance of clinicians devoting effective strategies and efforts to optimizing PAP adherence in patients with OSA.

Infographic showing adjusted average 6-month healthcare costs among OSA patients using PAP.
Data extracted from An J, et al. CHEST. 2023; doi:10.1016/j.chest.2023.01.025.

Using data from the Tele-OSA clinical trial, Hwang and colleagues evaluated 543 patients (mean age 50 years; 59% male; 42% non-Hispanic white; 40% Hispanic) with OSA and prescribed PAP to determine the relationship between adherence to PAP over 3 years and health care costs by multivariate generalized linear models.

The researchers used electronic health records and data from their integrated health care system to determine average health care costs ($2020) over 6-month periods. They looked at 11 types of health care utilization, including those related to sleep (office visits, equipment) and non-sleep related (eg, office visits, hospitalization, ED, pharmacy).

Over a 3-year period, just over half (52%; 36% white) of patients had poor adherence to PAP (< 2 hours/night), with a mean use of 0.5 hours per night. A quarter of patients (57% white) had high adherence (constantly 4 hours/night), with an average PAP use of 6.5 hours per night, and 22% (39% white) had moderate adherence (2-3.9 hours/night or inconsistent 4 hours/night), with an average PAP use of 3.7 hours per night.

The researchers found that mean PAP use increased significantly over time among patients in the high adherence group, while PAP use among those with low and moderate adherence decreased over time.

Average health care costs

When comparing healthcare costs between adherence groups, researchers adjusted for several covariates: age, sex, race/ethnicity, BMI category, Medicaid enrollment, smoking, apnea-hypopnea index (AHI) category, hypertension, comorbidity index of Charlson, mild liver disease, preoperative referral to a sleep clinic before randomization, no-show rate, log-transformed costs for the previous 6 months, time indicators representing the 6-month interval, and adherence to antihypertensive, antidiabetic, or statin medications.

After these adjustments, patients with low adherence had a mean 6-month healthcare cost of $4040, while those with high adherence reduced mean 6-month costs to $3207 for a significant difference of $832 (95% CI, $127-$1538) between two groups .

Costs for patients with moderate adherence fell between those observed for the low and high adherence groups ($3638) and were not significantly different from those of the low adherence group.

Individual costs, burden of OSA

When assessing the 11 different types of health care utilization individually, the researchers found that 6-month costs for those with high versus low adherence differed significantly for sleep-related office visits ($67 vs. $70; P = .01), sleep-related durable medical equipment ($141 vs. $76; P < .001), hospitalizations ($171 vs $2,076; P < .001), lab ($163 vs $216; P = .004) and phone calls ($42 vs. $59; P < 0.001).

Compared with the moderate adherence group, the high adherence group had significantly lower costs for non-sleep-related office visits ($829 vs $995; P = .03), durable medical equipment unrelated to sleep ($15 vs. $322; P = .04) and hospitalizations ($171 vs. $852; P = 0.01).

“Given that OSA is a chronic disease and the clinical benefit of PAP would theoretically be preventive by reducing the risk of chronic cardiovascular conditions such as hypertension, we were surprised that lower healthcare utilization and costs in those with high adherence to PAP were evident immediately within the first 6 months of starting PAP therapy,” said Healio’s Hwang. “This finding really complements our other surprising finding that the lower costs in those with high adherence were mostly seen in costs of hospitalization and other hospital services.” Thus, lower clinical events in acute care can lead to immediate potential cost savings.

In particular, patients with moderate versus low adherence had significantly reduced costs for other hospital services ($339 vs $1151; P = .02), but increased spending on sleep-related durable medical equipment ($127 vs $76; P < 0.001).

Although moderate to severe OSA (AHI 15) was not associated with cost differences between adherence groups in an first-specific stratified analysis, the researchers found significant cost differences between PAP adherence groups when evaluating those with mild OSA (AHI 5-14.9). Similar to the main finding above, among patients with mild OSA, those with low adherence had higher costs than patients with high (cost difference, $1,431; 95% CI, $223-$2,640) or moderate (cost difference, $1878; 95% CI, $657-$3100) adherence.

“We already did a similar analysis of a much larger group of patients (n = 25,000) in Southern California that showed similar conclusions,” Huang told Healio. “Furthermore, we plan to conduct the analysis over a longer period of time; we use machine learning to identify specific usage patterns that correlate with outcomes so that we can better personalize PAP usage goals; and perform additional analyzes on underrepresented minorities to highlight potential disparities that may be amenable to specific intervention strategies to achieve greater equity of outcomes,” Huang added.

Overcoming potential biases

Although it can be difficult to prevent bias from creeping into observational studies, this study by Hwang and colleagues demonstrates a good effort through covariate adjustments, according to an accompanying editorial from Jennifer S. Albrecht, Ph.D., Associate Professor in the Department of Epidemiology and Public Health at the University of Maryland School of Medicine and Vishesh K. Kapoor, MD, MPH, director of sleep medicine for the Division of Pulmonary, Critical Care and Sleep Medicine at the University of Washington.

“To better address healthy advocate bias, future studies could include additional measures of health behaviors such as receipt of immunizations, appropriate screening (eg, colonoscopy, mammography), and receipt of annual wellness visits,” write Albrecht and Kapoor. “Accounting for other behaviors not adequately captured in the medical record, such as diet, physical activity, and regular alcohol use, would also be helpful.”




Disclosures: Hwang reports receiving research funding from the AASM Foundation, the Kaiser Permanente Southern California Clinical Research and Evaluation Program, and the NIH. Please see the study for the relevant financial disclosures of all other authors. Albrecht reports that her institution has received research funding from the American Academy of Sleep Medicine, the Department of Defense, Merck, ResMed, and the ResMed Foundation. Kapur reports being a board member of the American Academy of Sleep Medicine.

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