EditorialPooled analysis of trials may, in the presence of heterogeneity inadvertently lead to fragile conclusions due to the importance of clinically relevant variables being either hidden or lost when the findings are pooled
Section snippets
Clinical perspectives
There is striking evidence of clinical heterogeneity among the three trials which casts doubt on the authors conclusions. The trials RE-NOVATE [3], which evaluated patients undergoing elective hip surgery, and RE-MOBILIZE [4] and RE-MODEL [5], which evaluated patients undergoing elective knee surgery, were randomized double-blind non-inferiority trials, comparing the efficacy and safety of dabigatran (150 mg or 220 mg once daily) starting post-operatively, with subcutaneous enoxaparin. While the
Statistical perspectives
A critical issue regarding pooling the findings of individual trials is the presence or absence of heterogeneity [7], [8]. To establish whether heterogeneity was or was not present, the authors assessed heterogeneity of the common risk difference amongst the studies using Cochrane's X2 (Q statistic) and the I2 statistic. Statistically significant heterogeneity was considered to be present if P < 0.10 was observed and where I2 was greater than 50% heterogeneity was also considered to be
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Systematic review of randomized controlled trials of new anticoagulants for venous thromboembolism prophylaxis in major orthopedic surgeries, compared with enoxaparin
2013, Annals of Vascular SurgeryCitation Excerpt :Furthermore, heterogeneity was not always considered in the generated conclusions, and therefore panoramic comparisons were troublesome. Pooled analyses were also performed for rivaroxaban37 and dabigatran,38 but the populations included were not per-protocol, as in the original reports, and may, in the presence of heterogeneity, inadvertently lead to fragile conclusions.39 Therefore, no previous systematic review was conducted summarizing all new anticoagulant trials (publications after 2000) in a unique meta-analysis.
Risk factors and prognosis of perioperative hidden blood loss in hip replacement patients
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