Decision Modeling in Sleep Apnea: The Critical Roles of Pretest Probability, Cost of Untreated Obstructive Sleep Apnea, and Time Horizon

Proposal of a diagnostic algorithm based on the use of pulse oximetry in obstructive sleep apnea

PURPOSE

The aims of this study were to assess the cut-off values for oxygen desaturation index ≥ 3% (ODI3) to confirm obstructive sleep apnea (OSA) in subjects undergoing polysomnography (PSG) and home-based respiratory polygraphy (RP), and to propose an algorithm based on pulse oximetry (PO) for initial management of patients with suspected OSA.

METHODS

This was an observational, cross-sectional, retrospective study. ODI3 was used to classify subjects as healthy (no OSA = AHI < 5 or < 15 events/h) or unhealthy (OSA = AHI ≥ 5 or ≥ 15 events/h). On the PSG or experimental group (Exp-G), we determined ODI3 cut-off values with 100% specificity (Sp) for both OSA definitions. ODI3 values without false positives in the Exp-G were applied to a validation group (Val-G) to assess their performance. A strategy based on PO was proposed in patients with suspected OSA.

RESULTS

In Exp-G (PSG) 1141 patients and in Val-G (RP) 1141 patients were included. In Exp-G, ODI3 > 12 (OSA = AHI ≥ 5) had a sensitivity of 69.5% (CI95% 66.1-72.7) and Sp of 100% (CI95% 99-100), while an ODI3 ≥ 26 had a 53.8% sensitivity (CI95% 49.3-58.2) and Sp of 100% (CI95% 99.4-100) for AHI ≥ 15. A high pretest probability for OSA by Berlin questionaire (≥ 2 categories) had a lower diagnostic performance than by STOP-BANG questionnaire ≥ 5 points (AHI ≥ 5: 0.856 vs. 0.899, p < 0.001; AHI ≥ 15: 0.783 vs. 0.807, p 0.026).

CONCLUSION

We propose the initial use of PO at home in cases of moderate-to-high pretest probability of OSA. This algorithm considers PO as well as RP and PSG for more challenging cases or in case of doubt.

Value of Surgical and Nonsurgical Treatment for Sleep Apnea: A Closer Look at Healthcare Utilization

OBJECTIVE

To determine how surgery, continuous positive airway pressure (CPAP), and no treatment impact healthcare utilization in patients who have obstructive sleep apnea (OSA).

STUDY DESIGN

This is a retrospective cohort study of patients between the ages of 18 and 65 that were diagnosed with OSA (9th International Classification of Diseases) from January 2007 to December 2015. Data were collected over 2 years, and prediction models were generated to evaluate trends over time.

SETTING

A population-based study using real-world data and insurance databases.

METHODS

A total of 4,978,649 participants were identified, all with at least 25 months of continuous enrollment. Patients with previous soft tissue procedures not approved for OSA (nasal surgery), or without continuous insurance coverage were excluded. A total of 18,050 patients underwent surgery, 1,054,578 were untreated, and 799,370 received CPAP. IBM Marketscan Research database was utilized to describe patient-specific clinical utilization, and expenditures, across outpatient, and inpatient services, and medication prescriptions.

RESULTS

When the cost of the intervention was eliminated in the 2-year follow-up, the monthly payments of group 1 (surgery) were significantly less than group 3 (CPAP) in overall, inpatient, outpatient, and pharmaceutical payments (p < .001). The surgery group was associated with less cumulative payments compared to the other 2 groups when the cost of the intervention (CPAP or surgery) was eliminated in all comorbidities and age groups.

CONCLUSION

Treating OSA with surgery can lessen overall healthcare utilization compared to no treatment and CPAP.

Economic evaluation of CPAP therapy for obstructive sleep apnea: a scoping review and evidence map

PURPOSE

To synthesize findings of economic evaluations investigating cost-effectiveness of continuous positive airway pressure (CPAP) for obstructive sleep apnea (OSA) and of strategies of organization of care related to CPAP therapy.

METHODS

Scoping review with searches conducted in MEDLINE, CRD, LILACS, and Embase in August 2020. Eligible studies were economic evaluations comparing CPAP to other alternative or assessing strategies of care for CPAP therapy. Results were presented narratively, and incremental cost-effectiveness ratios (ICER) were presented in evidence maps.

RESULTS

Of 34 studies, 3 concluded that CPAP is less costly and more effective when compared to usual care. Most studies indicated that CPAP is associated with better health outcomes, but at higher prices. ICER ranged from USD 316 to 98,793 per quality-adjusted life years (QALY) gained (median 16,499; IQR 8267 to 33,119). One study concluded that CPAP is more costly and less effective, when treatment is applied to all patients, regardless of disease severity. Variability of ICER was mainly due to definition of population and applied time horizons. When CPAP was compared to mandibular advancement device, ICER ranged from USD 21,153 to 361,028 (median 89,671; IQR 26,829 to 295,983), which represents the investment in CPAP therapy required to obtain one extra QALY. Three studies assessed the effects of organizing CPAP therapy in primary care, which was cost-effective or cost-saving.

CONCLUSIONS

Compared to usual care, CPAP is cost-effective after the second year of treatment, when indicated for moderate-to-severe OSA. CPAP therapy may be even more cost-effective by using different strategies of organization of care. These findings may inform decision making related to CPAP reimbursement in health systems.

CLINICAL TRIAL REGISTRATION NUMBER

Not applicable.

Cost-Benefit Analysis From the Payor's Perspective for Screening and Diagnosing Obstructive Sleep Apnea During Inpatient Rehabilitation for Moderate to Severe TBI

OBJECTIVE

To describe the cost benefit of 4 different approaches to screening for sleep apnea in a cohort of participants with moderate to severe traumatic brain injury (TBI) receiving inpatient rehabilitation from the payor's perspective.

DESIGN

A cost-benefit analysis of phased approaches to sleep apnea diagnosis.

SETTING

Six TBI Model System Inpatient Rehabilitation Centers.

PARTICIPANTS

Trial data from participants (N=214) were used in analyses (mean age 44±18y, 82% male, 75% white, with primarily motor vehicle-related injury [44%] and falls [33%] with a sample mean emergency department Glasgow Coma Scale of 8±5).

INTERVENTION

Not applicable.

MAIN OUTCOME

Cost benefit.

RESULTS

At apnea-hypopnea index (AHI) ≥15 (34%), phased modeling approaches using screening measures (Snoring, Tired, Observed, Blood Pressure, Body Mass Index, Age, Neck Circumference, and Gender [STOPBANG] [-$5291], Multivariable Apnea Prediction Index MAPI [-$5262]) resulted in greater cost savings and benefit relative to the portable diagnostic approach (-$5210) and initial use of laboratory-quality polysomnography (-$5,011). Analyses at AHI≥5 (70%) revealed the initial use of portable testing (-$6323) relative to the screening models (MAPI [-$6250], STOPBANG [-$6237) and initial assessment with polysomnography (-$5977) resulted in greater savings and cost-effectiveness.

CONCLUSIONS

The high rates of sleep apnea after TBI highlight the importance of accurate diagnosis and treatment of this comorbid disorder. However, financial and practical barriers exist to obtaining an earlier diagnosis during inpatient rehabilitation hospitalization. Diagnostic cost savings are demonstrated across all phased approaches and OSA severity levels with the most cost-beneficial approach varying by incidence of OSA.

Practical and rapidly-implemented parameters for assessing APAP titration failure

BACKGROUND

This study aimed to show the predictive value of simple polysomnographic parameters including latency of deep sleep (nREM3), latency of rapid eye movement sleep (REM), and minimum oxygen saturation (SpO₂) for predicting failure of autoadjusting positive airway pressure (APAP) titration.

METHODS

Out of 1470 patients with moderate to severe obstructive sleep apnea syndrome (OSAS) who underwent APAP titration between July 1, 2016, and December 31, 2017, 22 patients with titration failure were enrolled in the study. The demographic and polysomnographic characteristics of this group were compared with 44 patients with an adequate APAP titration who were matched with the titration failure group by age, sex, and OSAS severity. The periods between the start of sleep and the start of REM and nREM3 stages were noted as REM latency and nREM3 latency, respectively.

RESULTS

The between group differences in the parameters including nREM3 latency, REM latency, and minimum SpO₂ during the titration test were statistically significant (p = 0.004, p = 0.008, p <0.001 respectively). Possible threshold values to predict failure of APAP titration were found as 40 min and 135 min for nREM3 and REM latencies, respectively. The best threshold for minimum SpO₂ was 86% with an 86.4% of sensitivity. Despite the high negative predictive values (81% for nREM3 latency, 75% for REM latency), the sensitivities (63.6% for nREM3 latency, 54.5% for REM latency) of the prior parameters in determining titration failure were relatively low.

CONCLUSION

The minimum SpO₂ < 86% can be used as a readily available indicator of APAP titration failure. nREM3 and REM latencies may be regarded as supplementary indicators in detecting the patients who may need an advanced PAP device.

Transition to Adult Care for Obstructive Sleep Apnea

Obstructive sleep apnea may occur throughout the lifespan, with peak occurrences in early childhood and during middle and older age. Onset in childhood is overwhelmingly due to adeno-tonsillar hypertrophy, while in adulthood, contributors include risk factors, such as obesity, male sex, and aging. More recently, there has been a precipitous increase in the prevalence of obstructive sleep apnea in youth. Drivers of this phenomenon include both increasing obesity and the survival of children with complex medical conditions into adulthood. Appropriate treatment and long-term management of obstructive sleep apnea is critical to ensure that these youth maintain well-being unfettered by secondary comorbidities. To this end, patient engagement and seamless transition of care from pediatric to adult health care systems is of paramount importance. To date, this is an unacknowledged and unmet need in most sleep programs. This article highlights the need for guideline-driven sleep disorder transition processes and illustrates the authors’ experience with the development of a program for sleep apnea.

The Impact of Treatments for OSA on Monetized Health Economic Outcomes: A Systematic Review

OBJECTIVE

To review systematically the published literature regarding the impact of treatment for OSA on monetized health economic outcomes.

METHODS

Customized structured searches were performed in PubMed, Embase (Embase.com), and the Cochrane Central Register of Controlled Trials (Wiley) databases. Reference lists of eligible studies were also analyzed. Titles and abstracts were examined, and articles were identified for full-text review. Studies that met inclusion criteria were evaluated in detail, and study characteristics were extracted using a standardized template. Quantitative characteristics of the studies were summarized, and a qualitative synthesis was performed.

RESULTS

Literature searches identified 2,017 nonredundant abstracts, and 196 full-text articles were selected for review. Seventeen studies met inclusion criteria and were included in the final synthesis. Seven studies included formal cost-effectiveness or cost-utility analyses. Ten studies employed cohort designs, and four studies employed randomized controlled trial or quasi-experimental designs. Positive airway pressure was the most common treatment modality, but oral appliances and surgical approaches were also included. The most common health economic outcomes were health-care use (HCU) and quality-adjusted life years (QALYs). Follow-ups ranged from 6 weeks to 5 years. Overall, 15 of 18 comparisons found that treatment of OSA resulted in a positive economic impact. Treatment adherence and OSA severity were positively associated with cost-effectiveness.

CONCLUSIONS

Although study methodologies varied widely, evidence consistently suggested that treatment of OSA was associated with favorable economic outcomes, including QALYs, within accepted ranges of cost-effectiveness, reduced HCU, and reduced monetized costs.

Cost-effectiveness strategies in OSAS management: a short review

Obstructive sleep apnoea (OSAS) is an underdiagnosed chronic disease with a high prevalence in adults. It is becoming a significant social problem, since it is associated with a worsening in quality of life and increase in mortality. The cost-effectiveness ratio of diagnostic and therapeutic management of OSAS is a strategic issue to counteract the expected increasing demand of objective testing. OSAS patients with any clinical evidence of comorbidities must be studied using simplified and less expensive systems such as Home Sleep Testing (HST). On the other hand, Sleep Laboratory Polysomnography (PSG) is the gold standard to manage OSAS patients with comorbidities. It should be pointed out that the use of HST can lead to incorrect diagnosis in poorly selected OSAS subjects. This short review discusses various topics for the proper diagnosis and treatment of OSAS in view of epidemiological factors and results in terms of costs and social benefit of the disease. Whatever the strategy chosen and/or the organisational model adopted for managing OSAS, it cannot and should not take into account only cost-effectiveness. Long-term prospective studies evaluating cost-effectiveness ratios and outcomes of OSAS treatment of hospital management models versus home care models are needed.

Sleep devices: wearables and nearables, informational and interventional, consumer and clinical

The field of sleep is in many ways ideally positioned to take full advantage of advancements in technology and analytics that is fueling the mobile health movement. Combining hardware and software advances with increasingly available big datasets that contain scored data obtained under gold standard sleep laboratory conditions completes the trifecta of this perfect storm. This review highlights recent developments in consumer and clinical devices for sleep, emphasizing the need for validation at multiple levels, with the ultimate goal of using personalized data and advanced algorithms to provide actionable information that will improve sleep health.

Utility of Acoustic Pharyngometry for the Diagnosis of Obstructive Sleep Apnea

RATIONALE

Owing to resource limitations, the testing of patients for obstructive sleep apnea (OSA) is often delayed. There is a need to accurately triage and expedite testing in those with a high pretest probability of OSA. Acoustic pharyngometry is a simple, noninvasive technique used to assess the upper airway cross-sectional area (UA-XSA), which is known to be reduced in those with OSA.

OBJECTIVES

To determine the discriminative ability and predictive value of UA-XSA measurements by acoustic pharyngometry for OSA.

METHODS

We conducted a cross-sectional study with a clinical cohort of consecutive adults with suspected OSA who had undergone both polysomnography and acoustic pharyngometry. OSA was defined as an apnea-hypopnea index greater than or equal to 5. Multivariable logistic regression analyses and receiver operating characteristic curves were used.

MEASUREMENTS AND MAIN RESULTS

The cohort included 576 subjects, 87% of whom had OSA and 64% of whom were men. The subjects' median body mass index (BMI) was 30.3 kg/m², and their median age was 57 years. The median UA-XSA at FRC when sitting was significantly smaller in those with OSA compared with those without OSA (3.3 cm² [interquartile range, 2.7-3.8] vs. 3.7 cm² [interquartile range, of 2.9-4.2]). When the analysis was controlled for age, sex, BMI, and comorbidities, the odds of OSA increased for every 1-cm² decrease in the mean UA-XSA FRC when sitting (odds ratio, 1.62; 95% confidence interval, 1.23-2.13). The mean UA-XSA provided fair discrimination for OSA (area under the curve, 0.60). A cutoff value of 3.75 cm², the point with the best sum of sensitivity and specificity, had sensitivity of 73% and specificity of 46%. The magnitude of the incremental discriminative value of UA-XSA over clinical variables (age, sex, BMI, and comorbidities) was small and nonsignificant (P = 0.5).

CONCLUSIONS

The mean UA-XSA at FRC when sitting or supine provided no further significant advantage over clinical variables for the discernment of OSA.

The utility of home sleep apnea tests in patients with low versus high pre-test probability for moderate to severe OSA

PURPOSE

Home sleep apnea tests (HSATs) are an alternative to attended polysomnograms (PSGs) when the pre-test probability for moderate to severe OSA is high. However, insurers often mandate use anytime OSA is suspected regardless of the pre-test probability. Our objective was to determine the ability of HSATs to rule in OSA when the pre-test probability of an apnea hypopnea index (AHI) in the moderate to severe range is low.

METHODS

Patients who underwent HSATs were characterized as low or high pre-test probability based on the presence of two symptoms of the STOP instrument plus either BMI > 35 or male gender. The odds of HSAT diagnostic for OSA dependent on pre-test probability was calculated. Stepwise selection determined predictors of non-diagnostic HSAT. As PSG is performed after HSATs that do not confirm OSA, false negative results were assessed.

RESULTS

Among 196 individuals, pre-test probability was low in 74 (38%) and high in 122 (62%). A lower percentage of individuals with a low versus high pre-test probability for moderate to severe OSA had HSAT results that confirmed OSA (61 versus 84%, p = 0.0002) resulting in an odds ratio (OR) of 0.29 for confirmatory HSAT in the low pre-test probability group (95% CI [0.146, 0.563]). Multivariate logistic regression demonstrated that age ≤ 50 (OR 3.10 [1.24-7.73]), female gender (OR 3.58[1.50-8.66]), non-enlarged neck circumference (OR 11.50 [2.50-52.93]), and the absence of loud snoring (OR 3.47 [1.30-9.25]) best predicted non-diagnostic HSAT. OSA was diagnosed by PSG in 54% of individuals with negative HSAT which was similar in both pre-test probability groups.

CONCLUSION

HSATs should be reserved for individuals with high pre-test probability for moderate to severe disease as opposed to any individual with suspected OSA.

A cost-effectiveness analysis of nasal surgery to increase continuous positive airway pressure adherence in sleep apnea patients with nasal obstruction

OBJECTIVES/HYPOTHESIS

Nasal surgery has been implicated to improve continuous positive airway pressure (CPAP) compliance in patients with obstructive sleep apnea (OSA) and nasal obstruction. However, the cost-effectiveness of nasal surgery to improve CPAP compliance is not known. We modeled the cost-effectiveness of two types of nasal surgery versus no surgery in patients with OSA and nasal obstruction undergoing CPAP therapy.

STUDY DESIGN

Cost-effectiveness decision tree model.

METHODS

We built a decision tree model to identify conditions under which nasal surgery would be cost-effective to improve CPAP adherence over the standard of care. We compared turbinate reduction and septoplasty to nonsurgical treatment over varied time horizons from a third-party payer perspective. We included variables for cost of untreated OSA, surgical cost and complications, improved compliance postoperatively, and quality of life.

RESULTS

Our study identified nasal surgery as a cost-effective strategy to improve compliance of OSA patients using CPAP across a range of plausible model assumptions regarding the cost of untreated OSA, the probability of adherence improvement, and a chronic time horizon. The relatively lower surgical cost of turbinate reduction made it more cost-effective at earlier time horizons, whereas septoplasty became cost-effective after a longer timespan.

CONCLUSIONS

Across a range of plausible values in a clinically relevant decision model, nasal surgery is a cost-effective strategy to improve CPAP compliance in OSA patients with nasal obstruction. Our results suggest that OSA patients with nasal obstruction who struggle with CPAP therapy compliance should undergo evaluation for nasal surgery.

LEVEL OF EVIDENCE

2c Laryngoscope, 127:977-983, 2017.