Methodologic assessment of studies on endoscopic sinus surgery

Background: Functional endoscopic sinus surgery (ESS) has become the procedure of choice for surgical treatment of chronic rhinosinusitis. Does the published literature support the claims of greater efficacy than medical treatment alone or older sinus procedures? Objective: To analyze the methodology of the published literature regarding the efficacy of ESS. Data Sources: MEDLINE search for primary studies published in 198 7 through 200 1, written in the English language, reporting results on more than 100 patients, using the MeSH (medical subject headings) terms sinusitis [subheadings surgery or therapy] and endoscopy. Study Selection: Of 512 studies initially identified, 29 studies met the inclusion and exclusion criteria for further assessment of methodologic criteria. An additional 6 studies were found when the reference lists of reviews or included studies were searched. Data Extraction: Articles were evaluated for 4 core (inclusion/exclusion criteria, control group, intervention, and clear outcome measure) methodologic criteria essential to the determination of efficacy of ESS. Eight additional methodologic criteria were also used to rate the articles. Data Synthesis: Three studies met all 4 core methodologic criteria. Only 4 of 35 studies used a control group to evaluate efficacy of ESS to treat chronic sinusitis. Mean number of criteria met was 7.2, with a range of 2 to 11. Conclusions: Absence of a control group is the most important reason that studies are unable to scientifically assess the comparative efficacy of ESS to medical therapy or other sinus procedures. The methodologic criteria described here can be used to evaluate studies of interventions for other disorders.