Background: The validity and applicability of before-after studies compared to randomised controlled trials of fluconazole prophylaxis for very low birthweight infants is uncertain.
Aims: We aimed to examine whether the study design (before-after studies compared to randomised controlled trials) affected the estimate of effect size yielded in meta-analyses and to explore possible causes for any differences detected.
Methods: We undertook a systematic review and meta-analysis of before-after studies that assessed the effect of fluconazole prophylaxis on the incidence of invasive fungal infection in very low birthweight infants. Data were compared with estimates generated from meta-analyses of randomised controlled trials. Funnel plots were examined for evidence of publication bias.
Results: Meta-analysis of eleven before-after studies found a reduced risk of invasive fungal infection following introduction of fluconazole prophylaxis: relative risk 0.19 (95% confidence interval 0.13 to 0.27). This estimate is significantly lower than the estimate from meta-analysis of randomised controlled trials: relative risk 0.48 (95% confidence interval 0.31 to 0.73). Funnel plot inspection of before-after studies revealed that smaller studies with large effects sizes contributed an excess of data points suggesting that publication bias contributes to the inflation of the effect size estimate.
Conclusions: Data from before-after studies should be interpreted and applied cautiously. Evidence to guide policy and practice for antifungal prophylaxis for very low birthweight infants should be derived from well-designed randomised controlled trials.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.