Article type
Year
Abstract
Background:
Treatment for age-related macular degeneration (AMD) has been revolutionized in the past 20 years with the introduction of anti-vascular endothelial growth factor (anti-VEGF) therapies. The field is fast-moving with an information overload in the medical literature.
Objectives:
To compare published systematic reviews (SRs) of randomized controlled trials (RCTs) of anti-VEGF therapies for AMD, and to assess the degree of overlap (i.e. extent to which SRs cite the same RCTs and evaluate the same interventions) and reasons for discordance among the SRs.
Methods:
We searched for eligible SRs in a database of eyes and vision SRs developed and maintained by the Cochrane Eyes and Vision Group US Satellite (updated as of 2012). We considered only RCTs included in the SRs when investigating the degree of overlap. We explored the reasons for discordance among RCTs included in SRs, such as the search date, interventions, and follow-up time.
Results:
We identiļ¬ed 10 SRs that examined the effectiveness and/or safety of anti-VEGF therapy for AMD published between May 2007 and July 2011 (searches conducted between September 2006 and June 2010). Twelve unique RCTs were included across all the SRs (Figure). With the exception of two RCTs published after nine of the SRs, there was high degree of overlap among SRs, with 10 of the RCTs included by at least three reviews (range: 3 to 8). In terms of specific citations, there was a total of 28 citations for the 11 included RCTs (range: 6 to 19 citations per SR). Earlier SRs included pegaptanib, whereas later SRs tended to focus on head-to-head comparisons of ranibizumab versus bevacizumab.
Conclusions:
Publication dates and restriction in eligibility criteria regarding interventions and follow-up times accounted for the majority of discordance among SRs. Concordance of effect estimates and conclusions is worth further investigation. Published within a five-year span, the SRs added new RCTs as they were published, indicating this is a hot field. Keeping up with the evidence is important. Cochrane should discuss how to ensure timely updates of priority topics given competing demands on resources.
Treatment for age-related macular degeneration (AMD) has been revolutionized in the past 20 years with the introduction of anti-vascular endothelial growth factor (anti-VEGF) therapies. The field is fast-moving with an information overload in the medical literature.
Objectives:
To compare published systematic reviews (SRs) of randomized controlled trials (RCTs) of anti-VEGF therapies for AMD, and to assess the degree of overlap (i.e. extent to which SRs cite the same RCTs and evaluate the same interventions) and reasons for discordance among the SRs.
Methods:
We searched for eligible SRs in a database of eyes and vision SRs developed and maintained by the Cochrane Eyes and Vision Group US Satellite (updated as of 2012). We considered only RCTs included in the SRs when investigating the degree of overlap. We explored the reasons for discordance among RCTs included in SRs, such as the search date, interventions, and follow-up time.
Results:
We identiļ¬ed 10 SRs that examined the effectiveness and/or safety of anti-VEGF therapy for AMD published between May 2007 and July 2011 (searches conducted between September 2006 and June 2010). Twelve unique RCTs were included across all the SRs (Figure). With the exception of two RCTs published after nine of the SRs, there was high degree of overlap among SRs, with 10 of the RCTs included by at least three reviews (range: 3 to 8). In terms of specific citations, there was a total of 28 citations for the 11 included RCTs (range: 6 to 19 citations per SR). Earlier SRs included pegaptanib, whereas later SRs tended to focus on head-to-head comparisons of ranibizumab versus bevacizumab.
Conclusions:
Publication dates and restriction in eligibility criteria regarding interventions and follow-up times accounted for the majority of discordance among SRs. Concordance of effect estimates and conclusions is worth further investigation. Published within a five-year span, the SRs added new RCTs as they were published, indicating this is a hot field. Keeping up with the evidence is important. Cochrane should discuss how to ensure timely updates of priority topics given competing demands on resources.