Interventions for age-related macular degeneration: What is the quality of the evidence?

Article type
Authors
Ssemanda E1, Ugarte Gil C2, Li T1, Dickersin K1
1Cochrane Eyes and Vision Group, USA
2Johns Hopkins School of Public Health, USA
Abstract
Background: Systematic reviews on interventions for age-related macular degeneration (AMD) are essential for making informed clinical inferences and providing evidence-based care.

Objectives: This report examined the quality of systematic reviews on interventions for AMD using modified versions of the Critical Appraisal Skills Program (CASP), the Assessment of Multiple Systematic Reviews (AMSTAR), and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA).

Methods: PubMed/Medline, EMBASE and CENTRAL were searched for relevant reviews in 2009 and updated in 2012. We selected reviews, which asked a focused clinical question, used explicit, pre-specified scientific methods, and examined the efficacy of an intervention for AMD. Two authors independently extracted and assessed the characteristics and methodological quality of each review.

Results: Out of 7676 citations, 36 systematic reviews met our inclusion criteria. 36% of systematic reviews were classified as a Cochrane Review. Most of the systematic reviews targeted neovascular AMD and investigated anti-VEGF interventions, dietary supplements or photodynamic therapy. Although the majority of systematic reviews presented a search description, 56% searched non-English journals, 47% included unpublished data, and 39% searched for ongoing studies. 56% and 56% reported at least two data abstractors screened abstracts and full-texts respectively. 53% of systematic reviews assessed the risk of bias independently. 94% of systematic reviews appraised the included studies qualitatively. Nearly all systematic reviews explored the limitations at the study and outcome levels, while 42% discussed limitations at the review level. Only 36% did not report the source of monetary or material support of the review. 47% of reviews were judged to be reliable. We found Cochrane systematic reviews to be more reliable than non-Cochrane systematic reviews.

Conclusions: We identified areas for improvement in systematic review conduct. The quality of systematic reviews varied, with better quality found in Cochrane Reviews as compared to non-Cochrane Reviews.