Eur Spine J DOI 10.1007/s00586-015-3964-4
LETTER TO THE EDITOR
Letter regarding Li et al. entitled ‘‘Is tranexamic acid effective and safe in spinal surgery? A meta-analysis of randomized controlled trials’’ Guoping Liao1,2 • Xing Feng3 • Tieshan Wang4 • Jingming Lin1
Received: 1 June 2014 / Revised: 13 April 2015 / Accepted: 14 April 2015 Ó Springer-Verlag Berlin Heidelberg 2015
To the Editor, Li et al. [1] conducted a meta-analysis to assess the effectiveness and safety of tranexamic acid (TXA) in reducing blood loss and transfusion in spinal surgery. They calculated the pooled risk ratio (RR) or mean difference (MD) with 95 % confidence intervals (95 % CIs) using different effect models and concluded that intravenous use of TXA for patients undergoing spinal surgery is effective and safe, which could reduce the total blood loss and the need for blood transfusion, yet does not increase the risk of postoperative deep-vein thrombosis (DVT). Before their results can be accepted, we would like to express some concerns in relation to their meta-analysis. Firstly, the investigators (Li et al.) clarified that ‘‘MEDLINE (1966–March 2012), Embase (1980–March
& Jingming Lin [email protected] 1
Department of Pharmacy, Zhujiang Hospital of Southern Medical University, Guangzhou 510282, Guangdong Province, People’s Republic of China
2
Changning Hospital of Traditional Chinese Medicine, Changning 421500, Hunan Province, People’s Republic of China
3
Department of Pharmacy, The Medical College of Hunan Normal University, Changsha 410013, Hunan Province, People’s Republic of China
4
Department of Pharmacy, Guangdong Women and Children Hospital and Health Institute, Guangzhou 511400, Guangdong Province, People’s Republic of China
2012), and the Cochrane Central Register of Controlled Trials were searched for eligible studies’’. The small number of required papers would be an important limitation of this meta-analysis. To make the article more credible, we suggest that more electronic databases, such as Web of Science, CINAHL and the Chinese Biomedical Database should be systematically searched by the investigators. Secondly, it was found that there were significant heterogeneities between studies in Fig. 2 (I2 = 62 %) and Fig. 4 (I2 = 68 %). Meanwhile, the studies were combined by the method of inverse variance (IV) with the assumptions of a fixed effects model, rather than DerSimonian and Laird random effects model. In our opinion, the studies should be combined by DerSimonian and Laird random effects model, which considers both withinand between-study variations. As there are significant heterogeneities, the investigators did not make any heterogeneity analysis. The sensitivity analyses should be conducted to find out the source of the significant heterogeneities. Meanwhile, the investigators used a table to provide us the subgroup analysis results of transfusion and total blood loss outcome, rather a forest plots. In our opinion, the subgroup analysis should be carried on the forest plots, which could show more details. Thirdly, we suggest that the investigators should use some statistical tests (Egger’s linear regression test or Begg’s rank correlation test) to evaluate the publication bias. Finally, the investigators did not follow the Quality of Reporting of Meta-analyses (QUOROM). As a minor suggestion, adding QUOROM checklist could make this meta-analysis better. Thanks go to the investigators for their contribution to supplying us with a assessment the effectiveness and safety
123
Eur Spine J
of TXA in reducing blood loss and transfusion in spinal surgery. However, further high-quality randomized controlled trials (RCTs) should be designed to examine the best therapeutic dose and application time of TXA to reduce blood loss in spinal surgery. Conflict of interest
123
None.
Reference 1. Li ZJ, Fu X, Xing D, Zhang HF, Zang JC, Ma XL (2013) Is tranexamic acid effective and safe in spinal surgery? A metaanalysis of randomized controlled trials. Eur Spine J 22(9):1950–1957
LETTER TO THE EDITOR
Letter regarding Li et al. entitled ‘‘Is tranexamic acid effective and safe in spinal surgery? A meta-analysis of randomized controlled trials’’ Guoping Liao1,2 • Xing Feng3 • Tieshan Wang4 • Jingming Lin1
Received: 1 June 2014 / Revised: 13 April 2015 / Accepted: 14 April 2015 Ó Springer-Verlag Berlin Heidelberg 2015
To the Editor, Li et al. [1] conducted a meta-analysis to assess the effectiveness and safety of tranexamic acid (TXA) in reducing blood loss and transfusion in spinal surgery. They calculated the pooled risk ratio (RR) or mean difference (MD) with 95 % confidence intervals (95 % CIs) using different effect models and concluded that intravenous use of TXA for patients undergoing spinal surgery is effective and safe, which could reduce the total blood loss and the need for blood transfusion, yet does not increase the risk of postoperative deep-vein thrombosis (DVT). Before their results can be accepted, we would like to express some concerns in relation to their meta-analysis. Firstly, the investigators (Li et al.) clarified that ‘‘MEDLINE (1966–March 2012), Embase (1980–March
& Jingming Lin [email protected] 1
Department of Pharmacy, Zhujiang Hospital of Southern Medical University, Guangzhou 510282, Guangdong Province, People’s Republic of China
2
Changning Hospital of Traditional Chinese Medicine, Changning 421500, Hunan Province, People’s Republic of China
3
Department of Pharmacy, The Medical College of Hunan Normal University, Changsha 410013, Hunan Province, People’s Republic of China
4
Department of Pharmacy, Guangdong Women and Children Hospital and Health Institute, Guangzhou 511400, Guangdong Province, People’s Republic of China
2012), and the Cochrane Central Register of Controlled Trials were searched for eligible studies’’. The small number of required papers would be an important limitation of this meta-analysis. To make the article more credible, we suggest that more electronic databases, such as Web of Science, CINAHL and the Chinese Biomedical Database should be systematically searched by the investigators. Secondly, it was found that there were significant heterogeneities between studies in Fig. 2 (I2 = 62 %) and Fig. 4 (I2 = 68 %). Meanwhile, the studies were combined by the method of inverse variance (IV) with the assumptions of a fixed effects model, rather than DerSimonian and Laird random effects model. In our opinion, the studies should be combined by DerSimonian and Laird random effects model, which considers both withinand between-study variations. As there are significant heterogeneities, the investigators did not make any heterogeneity analysis. The sensitivity analyses should be conducted to find out the source of the significant heterogeneities. Meanwhile, the investigators used a table to provide us the subgroup analysis results of transfusion and total blood loss outcome, rather a forest plots. In our opinion, the subgroup analysis should be carried on the forest plots, which could show more details. Thirdly, we suggest that the investigators should use some statistical tests (Egger’s linear regression test or Begg’s rank correlation test) to evaluate the publication bias. Finally, the investigators did not follow the Quality of Reporting of Meta-analyses (QUOROM). As a minor suggestion, adding QUOROM checklist could make this meta-analysis better. Thanks go to the investigators for their contribution to supplying us with a assessment the effectiveness and safety
123
Eur Spine J
of TXA in reducing blood loss and transfusion in spinal surgery. However, further high-quality randomized controlled trials (RCTs) should be designed to examine the best therapeutic dose and application time of TXA to reduce blood loss in spinal surgery. Conflict of interest
123
None.
Reference 1. Li ZJ, Fu X, Xing D, Zhang HF, Zang JC, Ma XL (2013) Is tranexamic acid effective and safe in spinal surgery? A metaanalysis of randomized controlled trials. Eur Spine J 22(9):1950–1957
