Initial use of portable monitoring versus polysomnography to confirm obstructive sleep apnea in symptomatic patients: An economic decision model

Ayas, N.T.; Fox, J.; Epstein, L.; Ryan, C.F.; Fleetham, J.A.

doi:10.1016/j.sleep.2009.08.015

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Volume 11, Issue 3 , Pages 320-324, March 2010

Initial use of portable monitoring versus polysomnography to confirm obstructive sleep apnea in symptomatic patients: An economic decision model

N.T. Ayas
- Sleep Disorders Program, University of British Columbia, Canada
- Respiratory Division, Department of Medicine, University of British Columbia, Canada
- Critical Care Division, Department of Medicine, University of British Columbia, Canada
- Centre for Clinical Epidemiology and Evaluation, Vancouver Coastal Health, Canada
- Corresponding author. Address: Sleep Disorders Program, University of British Columbia, 7th Floor, Diamond Centre, 2775 Laurel Street, Vancouver, BC, Canada V5Z 1M9. Tel.: +1 604 875 5133.
J. Fox
- Sleep Disorders Program, University of British Columbia, Canada
L. Epstein
- Sleep Health Centers, Harvard Medical School, Boston, MA, USA
C.F. Ryan
- Sleep Disorders Program, University of British Columbia, Canada
- Respiratory Division, Department of Medicine, University of British Columbia, Canada
J.A. Fleetham
- Sleep Disorders Program, University of British Columbia, Canada
- Respiratory Division, Department of Medicine, University of British Columbia, Canada

Received 21 April 2009; received in revised form 14 July 2009; accepted 17 August 2009.

Abstract

Background

When using portable (level III and level IV) studies to “rule in” obstructive sleep apnea (OSA) in symptomatic patients, the pre-test probability (P) needs to be sufficiently high to minimize patients with negative tests who require full polysomnography.

Methods

We used a theoretical decision analysis model to assess the pre-test probability above which it would be appropriate to use portable studies to rule in disease in symptomatic patients with suspected OSA. For the base case, we considered a symptomatically sleepy patient referred with a probability of OSA of P. We determined the lower threshold of P appropriate for a clinical algorithm based upon an initial ambulatory study compared to initial diagnosis with PSG by comparing costs using the PSG algorithm with a diagnostic algorithm involving initial assessment with a portable study.

Results

In our base case, the pre-test probability above which portable testing would be less costly than initial diagnostic PSG would be 0.47. When an initial split night study was compared to portable testing, the pre-test probability above which portable testing was more economically attractive was greater (0.68). Values of P, however, varied considerably depending on values of many variables, including costs of diagnostic testing and CPAP compliance.

Conclusions

Using a decision model, we have developed a theoretical framework to ascertain the pre-test disease probability above which portable studies would be economically attractive as an initial test in the assessment of patients with suspected OSA.

Keywords: Obstructive sleep apnea, Portable monitoring, Economics