This article is more than 5 years old. Information may no longer be current.
Placebo may be unnecessary when self-reported outcomes factor in clinical trials
Arch Ophthalmol. 2011;129(2):200-205.
Click Here to Manage Email Alerts
Sham treatment may be unnecessary in clinical trials when patient-reported outcomes weigh heavily on results and interviewers are masked to treatment assignment, a study suggested.
"This analysis, together with our earlier analysis of visual acuity outcomes, questions the necessity for sham (placebo) controls in randomized clinical trials in ophthalmology when other methods to minimize outcome assessment bias are incorporated into the design," the study authors said.
Investigators compared 2-year changes in National Eye Institute Visual Function Questionnaire (NEI-VFQ) and Short Form Health Survey (SF-36) scores between sham and no-treatment controls from two clinical trials.
Data were culled from the MARINA trial for Lucentis (ranibizumab, Genentech) for neovascular age-related macular degeneration and the Submacular Surgery Trials for subfoveal choroidal neovascularization secondary to AMD.
The MARINA trial included a control group that received sham injection; patients were masked to treatment. The Submacular Surgery Trials included a no-treatment control group in which patients were not masked. The NEI-VFQ and SF-36 were administered in both trials.
The analysis included 62 sham controls and 62 no-treatment controls matched according to seven criteria: NEI-VFQ scores; best corrected visual acuity in the better eye; presence or absence of choroidal neovascularization in the non-study eye; SF-36 physical component summary scores; SF-36 mental component summary scores; age; and sex. Data were available for 42 matched pairs interviewed at 2 years.
Results showed no significant differences between changes in the overall NEI-VFQ scores or subscores of the 42 matched pairs. Differences in the SF-36 driving and mental health subscores between sham and no-treatment controls approached statistical significance, the authors reported.
Patients should be randomized between sham and no-treatment control groups in clinical trials of new interventions for conditions for which no effective treatment is available, they said.