Dear Editor,We read with great interest the article titled “Red reflex test screening for neonates: A systematic review and meta-analysis” by Dr. Taksande and colleagues published in the August issue of Indian Journal of Ophthalmology.[1] The authors aimed to review the existing literature on red reflex screening in neonates and summarized its diagnostic accuracy for the early detection of various ocular pathology. The authors reported a low sensitivity and high specificity for the red reflex test in detecting any ocular disease. We appreciate the authors’ efforts in conducting this comprehensive study; however, we would like to draw attention to a methodological weakness and would like to suggest an improvement that could be made in this study.It is important to highlight that the authors did not assess and report for publication bias, an important methodological aspect of any meta-analysis. Publication is often attributed to unpublished or unreported studies that have not been published as they report negative or not significant results.[2] As publication bias was not reported in this meta-analysis, we analyzed the data from the 11 studies for the presence or absence of publication bias. We assessed the publication bias using Deeks funnel plot [Fig. 1], by plotting the natural logarithm of diagnostic odds ratio (DOR) on the x axis and inverse of the square root of the effective sample size [1/root (ESS)] on the y axis.[3] The results indicate no evidence of publication bias (P > 0.05).
Figure 1
Deeks funnel plot asymmetry test to evaluate publication bias
Deeks funnel plot asymmetry test to evaluate publication biasWe would like to congratulate the authors on their findings and hope that our improvement will add to the credibility of conclusions reported in this meta-analysis.
Authors: W Annefloor van Enst; Eleanor Ochodo; Rob J P M Scholten; Lotty Hooft; Mariska M Leeflang Journal: BMC Med Res Methodol Date: 2014-05-23 Impact factor: 4.615