Methodological and statistical problems in uvulopalatopharyngoplasty research: a follow-up study

Abstract

Objectives: To review the published literature on uvulopalatopharyngoplasty (UPPP) and assess the methodological quality of the research and compare it with a similar article published in 1995; and to determine what, if any, improvement in the methodological quality of the research resulted during the ensuing 10 years.

Design: Methodological and statistical evaluation of the published literature on UPPP. Thirty articles representing the clinical studies on UPPP and related procedures written from January 1996 to August 2005 were reviewed. Only articles reporting polysomnography data were included.

Results: Overall, the articles demonstrated fair methodological and statistical quality. Compared with the previous review by Schechtman et al, there was a slight increase in the number of articles that discussed statistical power and reported confidence intervals. There were increases in the mean sample size, the percentage of randomized controlled studies, the number of end points, and the use of validated subjective outcome measures; longer mean follow-up time; and more complete reporting of age and sex information. There was no increase in the percentage of published studies that used a prospective study design. None of the studies that required minimum acceptable baseline values of objective sleep parameter measures for enrollment indicated the use of separate screening and baseline assessments. There were 7 different definitions of sleep apnea and 17 different definitions of success in treatment.

Conclusions: There has been an overall improvement in the quality of the articles published on UPPP since 1995. Several areas still need improvement: use of more prospective studies, decrease in number of end points, use of separate screening and baseline assessments, and consensus in the definitions of sleep apnea and success.