Reporting of Noninferiority and Equivalence Randomized Trials for Major Prostaglandins: A Systematic Survey of the Ophthalmology Literature

Background:Standards for reporting clinical trials have improved the transparency of patientimportantresearch. The Consolidated Standards of Reporting Trials (CONSORT) published anextension to address noninferiority and equivalence trials. We aimed to determine the reportingquality of prostaglandin noninferiority and equivalence trials in the treatment of glaucoma.Methods:We searched, independently and in duplicate, 6 electronic databases for eligible trialsevaluating prostaglandins. We abstracted data on reporting of methodological criteria, includingreporting of per-protocol [PP] and intention-to-treat [ITT] analysis, sample size estimation withmargins, type of statistical analysis conducted, efficacy summaries, and use of hyperemia measures.Results:Trials involving the four major prostaglandin groups (latanoprost, travoprost,bimatoprost, unoprostone) were analyzed. We included 36 noninferiority and 11 equivalence trials.Seventeen out of the included 47 trials (36%, 95% Confidence Intervals [CI]: 24–51) werecrossover designs. Only 3 studies (6%, 95% CI: 2–17) reported a presented results of both ITT andPP populations. Twelve studies (26%, 95% CI: 15–39) presented only ITT results but mentionedthat PP population had similar results. Thirteen trials (28%, 95% CI: 17–42) presented only PPresults with no mention of ITT population results while 17 studies (36%, 95% CI: 24–51) presentedonly ITT results with no mention of PP population results. Thirty-four (72%, 95% CI: 58–83) ofstudies adequately described their margin of noninferiority/equivalence. Sequence generation wasreported in 22/47 trials (47%, 95% CI: 33–61). Allocation concealment was reported in only 10/47(21%, 95% CI: 12–35) of the trials. Thirty-five studies (74%, 95% CI: 60–85) employed masking ofat least two groups, 4/47 (9%, 95% CI: 3–20) masked only patients and 8/47 (17%, 95% CI: 9–30)were open label studies. Eight (17%, 95% CI: 9–30) of the 47 trials employed a combined test ofnoninferiority and superiority. We also found 6 differing methods of evaluating hyperemia.Conclusion:The quality of reporting noninferiority/equivalency trials in the field of glaucoma ismarkedly heterogeneous. The adoption of the extended CONSORT statement by journals willpotentially improve the transparency of this field.