Level 1 studies consist of randomized, placebo-controlled trials, which are considered to provide the strongest level of evidence. Without level 1 evidence however, results from any treatment option remain subject to speculation about potential placebo effect, selection bias, and other factors not directly a result of the treatment. Improvements in snoring intensity and daytime sleepiness may possibly be the result of placebo effects, secondary to the local anesthetic, or the result of scarring caused by the palatal implant delivery tool. Although these are unlikely reasons, only a properly designed study can provide objective, unbiased evidence of the true benefits of palatal implants.
The authors of the study, 'Palatal Implants for the Treatment of Obstructive Sleep Apnea/Hypopnea Syndrome and Snoring: A Double-Blind, Placebo-Controlled Study' designed the study to provide such evidence. In the study, the researchers describe the objective and subjective outcomes of the palatal implant patients and compare them to the control group who received an identical surgical treatment procedure without palatal implants. Study author Michael Friedman MD and colleagues will present the findings at the 110th Annual Meeting & OTO EXPO of the American Academy of Otolaryngology—Head and Neck Surgery Foundation, being held September 17-20, 2006, at the Metro Toronto Convention Centre, Toronto, Canada.
Fifty-five consecutive adults with history of snoring, daytime sleepiness, with mild to moderate OSAHS were enrolled. Quality of life (QOL) surveys, measures of snoring intensity, and Epworth Sleepiness Scale (ESS) were obtained. Patients were randomized to receive treatment either with three palatal implants or with a sham procedure without implants. Both physician and patient were blinded with respect to the randomization. At three months, polysomnography was repeated, and the subjects were reassessed with the above mentioned surveys. Objective and subjective results were then compared for the experimental and control groups.
Fifty-five patients completed the study (29 experimental and 26 control). AHI improvement was statistically significant for the experimental group. Objective cure was defined as 50 percent reduction in AHI and AHI < 20. Objective cure was statistically higher in the experimental group (37.9 percent vs. zero percent). In general, QOL scores showed greater improvement in the experimental group as compared with the control group. Subjective improvement in snoring (defined as at least a 50 percent decrease), was significantly higher in the experimental group than in the control group (62.1 percent vs. zero percent). Daytime sleepiness was significantly decreased in the experimental group and remained statistically unchanged in the control group.
This study presents randomized, placebo-controlled evidence on the effectiveness of palatal implant for improvement of AHI, QOL, snoring intensity, and daytime sleepiness. Patients treated with palatal implants demonstrate a significant improvement in objective and subjective measures when compared to a sham surgical control group in OSAHS. This study provides level 1 evidence that the palatal implant procedure can result in a significant decrease in AHI and that it has a 37.9 percent cure rate of mild and moderate OSAHS that compares favorably with UPPP. This study also provides level 1 evidence that the palatal implant procedure provides improvement in QOL, is effective in eliminating snoring in 62.1 percent of patients, and demonstrates a decrease in the level of daytime sleepiness. The overall effectiveness of the palatal implant procedure is comparable to permanent surgical alteration of the soft palate without the associated morbidity.