Evaluation of sham-CPAP as a placebo in CPAP intervention studies.

Abstract

STUDY OBJECTIVES:

To evaluate the use of sham-continuous positive airway pressure (CPAP) treatment as a placebo intervention.

DESIGN AND SETTING:

Analysis of polysomnograms performed in fixed order without sham-CPAP and on the first night of the sham-CPAP intervention in participants in the CPAP Apnea Trial North American Program (CATNAP), a randomized, placebo controlled trial evaluating the effects of CPAP treatment on daytime function in adults with newly diagnosed mild to moderate obstructive sleep apnea (apnea hypopnea index (AHI) 5-30).

PARTICIPANTS:

The first 104 CATNAP participants randomized to the sham-CPAP intervention arm.

MEASUREMENTS AND RESULTS:

Compared to the polysomnographic measures without sham-CPAP, the study on the first night with sham-CPAP had statistically significant differences that suggested a decrease in sleep quality: decreased sleep efficiency, increased arousal index, increased time in stage 1 NREM sleep, and prolonged latency to REM sleep. However, all of these differences had a relatively small effect size. Compared to the polysomnogram without sham-CPAP, the number of hypopneas on the sham-CPAP polysomnogram was significantly increased and the number of apneas significantly decreased. Relatively minor differences in AHI with and without sham-CPAP were present and were dependent on the criteria used to score hypopneas.

CONCLUSION:

Comparison of polysomnograms with and without sham-CPAP revealed differences that, although statistically significant, were small in magnitude and had relatively low effect sizes suggesting minimal clinical significance. The results support the use of sham-CPAP as a placebo intervention in trials evaluating the effects of CPAP treatment in patients with obstructive sleep apnea.

CLINICAL TRIAL INFORMATION:

This paper was a secondary analysis of clinical trial data. CATNAP: CPAP Apnea Trial North American Program, the trial from which the data were obtained, is registered with clinicaltrial.gov. Registration #NCT00089752.

• Authors: George W Rodway, Terri E Weaver, Cristina Mancini, Jacqueline Cater, Greg Maislin, Bethany Staley, Kathleen A Ferguson, Charles F P George, David A Schulman, Harly Greenberg, David M Rapoport, Joyce A Walsleben, Teofilo Lee-Chiong, Samuel T Kuna
• Journal: Sleep (Sleep) Vol. 33 Issue 2 Pg. 260-6 (Feb 2010) ISSN: 0161-8105 [Print] United States
• PMID: 20175410 (Publication Type: Comparative Study, Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Placebos

Topics

• Adult
• Aged
• Continuous Positive Airway Pressure (instrumentation)
• Equipment Design
• Female
• Humans
• Male
• Middle Aged
• Placebos
• Polysomnography
• Sleep Apnea, Obstructive (therapy)
• Sleep Stages