The management of established postherpetic neuralgia: a comparison of the quality and content of traditional vs. systematic reviews

Abstract

In the face of an exponential increase in published biomedical studies, dermatologists frequently turn to review articles in order to keep abreast of important developments in the treatment of skin diseases. Traditional review articles have recently been criticized on the basis of their incompleteness and susceptibility to bias. Such biases can be minimized by employing a systematic approach to gathering, combining and interpreting the evidence of treatment efficacy. Using eight predetermined quality criteria, we compared the quality of 10 traditional review with one systematic review of treatments for postherpetic neuralgia, which were identified from the Medline database for 1992-96. None of the 10 traditional review articles satisfied all eight criteria: one satisfied five, two satisfied four and the rest satisfied two or fewer criteria. There was a wide variation in the recommendations of the authors for the treatment of postherpetic neuralgia, often based on anecdotal evidence and clinical experience. On the other hand, the systematic review fulfilled seven of the eight quality criteria, failing only to discuss future directives. Furthermore, treatment recommendations were made solely on the basis of randomized controlled trials, which are considered to be the gold standard for measuring the benefits of any intervention. The variation in quality and treatment recommendations of traditional reviews is worrying. Systematic reviews should be encouraged in dermatology because they provide a summary of evidence of the effects of dermatological treatments, which has been derived using explicit methods widely accepted within science.

The Cochrane Skin Group: Promoting the Best Evidence

“…2 For example, Ladhani and Williams evaluated the quality of ten traditional expert reviews with one systematic review of treatments for postherpetic neuralgia according to eight predetermined quality criteria and found that none of the traditional reviews satisfied all eight criteria. 4 One satisfied five, two satisfied four, and the rest satisfied two or fewer quality criteria, whereas the systematic review satisfied seven criteria. Another reason why traditional reviews are less useful is that they quickly become outdated because unlike Cochrane reviews, there is no commitment on the part of the author or journal to update them.…”

Strengths and limitations of evidence-based dermatology

“…Systematic reviews of randomized clinical trials (RCTs) developed after it was realized that traditional reviews about treatments were done in quite arbitrary ways. [6] Traditional expert reviews may be appropriate for raising issues for discussion and debate, but they are much less suitable for summarizing treatment effects. The unsystematic approach used in most traditional reviews means that they are highly prone to bias and influence from hidden agendas.…”

“…The unsystematic approach used in most traditional reviews means that they are highly prone to bias and influence from hidden agendas. [6] Many have written “traditional” review articles in the past containing a biased selection of citations to support predetermined views. Indeed, the author confesses to having used the “file drawer” method to search for papers for a review of atopic eczema in the past [Figure 2].…”

Why is the center of evidence - based dermatology relevant to Indian dermatology ?

“…[9] A systematic review on the other hand, follows an explicit process of formulating a precise question, searching exhaustively for all relevant information, quality appraising that information, sometimes combining that information in a meta-analysis if appropriate, and then interpreting and disseminating that information.…”