Antifibrinolytic therapy: Evidence, bias, confounding (and politics!)

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Cardiac surgery can be complicated by postoperative bleeding and a need for blood transfusion and surgical re-exploration. Anti-fibrinolytic drugs such as aprotinin and tranexamic acid may reduce bleeding risks but could possibly increase thrombotic complications. Aprotinin, in particular, has recently been implicated in at least two large observational studies, but this could be because it is more widely used in high-risk cardiac surgical patients. Observational studies are prone to several important sources of bias, in particular, confounding by indication (high-risk patients are more likely to receive aprotinin and more likely to have postoperative complications, irrespective of their exposure to aprotinin). Although multivariate adjustment and propensity score-matching can adjust for confounding, there is no certainty that it removes all such bias. For all anti-fibrinolytic drugs, it remains unclear as to whether the beneficial effect on reduced bleeding outweighs a possible increased risk of thrombotic complications. Debate will continue until we have the results of definitive large randomized trials powered to detect a clinically important effect on outcome.

Original languageEnglish
Pages (from-to)308-310
Number of pages3
JournalJournal of Extra-Corporeal Technology
Volume39
Issue number4
Publication statusPublished - Dec 2007

Keywords

  • Antifibrinolytics
  • Aprotinin
  • Bias
  • Evidence

Cite this

@article{e960a67f89ad4aaf9209bf87847ba64f,
title = "Antifibrinolytic therapy: Evidence, bias, confounding (and politics!)",
abstract = "Cardiac surgery can be complicated by postoperative bleeding and a need for blood transfusion and surgical re-exploration. Anti-fibrinolytic drugs such as aprotinin and tranexamic acid may reduce bleeding risks but could possibly increase thrombotic complications. Aprotinin, in particular, has recently been implicated in at least two large observational studies, but this could be because it is more widely used in high-risk cardiac surgical patients. Observational studies are prone to several important sources of bias, in particular, confounding by indication (high-risk patients are more likely to receive aprotinin and more likely to have postoperative complications, irrespective of their exposure to aprotinin). Although multivariate adjustment and propensity score-matching can adjust for confounding, there is no certainty that it removes all such bias. For all anti-fibrinolytic drugs, it remains unclear as to whether the beneficial effect on reduced bleeding outweighs a possible increased risk of thrombotic complications. Debate will continue until we have the results of definitive large randomized trials powered to detect a clinically important effect on outcome.",
keywords = "Antifibrinolytics, Aprotinin, Bias, Evidence",
author = "Paul Myles",
year = "2007",
month = "12",
language = "English",
volume = "39",
pages = "308--310",
journal = "Journal of Extra-Corporeal Technology",
issn = "0022-1058",
number = "4",

}

Antifibrinolytic therapy : Evidence, bias, confounding (and politics!). / Myles, Paul.

In: Journal of Extra-Corporeal Technology, Vol. 39, No. 4, 12.2007, p. 308-310.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Antifibrinolytic therapy

T2 - Evidence, bias, confounding (and politics!)

AU - Myles, Paul

PY - 2007/12

Y1 - 2007/12

N2 - Cardiac surgery can be complicated by postoperative bleeding and a need for blood transfusion and surgical re-exploration. Anti-fibrinolytic drugs such as aprotinin and tranexamic acid may reduce bleeding risks but could possibly increase thrombotic complications. Aprotinin, in particular, has recently been implicated in at least two large observational studies, but this could be because it is more widely used in high-risk cardiac surgical patients. Observational studies are prone to several important sources of bias, in particular, confounding by indication (high-risk patients are more likely to receive aprotinin and more likely to have postoperative complications, irrespective of their exposure to aprotinin). Although multivariate adjustment and propensity score-matching can adjust for confounding, there is no certainty that it removes all such bias. For all anti-fibrinolytic drugs, it remains unclear as to whether the beneficial effect on reduced bleeding outweighs a possible increased risk of thrombotic complications. Debate will continue until we have the results of definitive large randomized trials powered to detect a clinically important effect on outcome.

AB - Cardiac surgery can be complicated by postoperative bleeding and a need for blood transfusion and surgical re-exploration. Anti-fibrinolytic drugs such as aprotinin and tranexamic acid may reduce bleeding risks but could possibly increase thrombotic complications. Aprotinin, in particular, has recently been implicated in at least two large observational studies, but this could be because it is more widely used in high-risk cardiac surgical patients. Observational studies are prone to several important sources of bias, in particular, confounding by indication (high-risk patients are more likely to receive aprotinin and more likely to have postoperative complications, irrespective of their exposure to aprotinin). Although multivariate adjustment and propensity score-matching can adjust for confounding, there is no certainty that it removes all such bias. For all anti-fibrinolytic drugs, it remains unclear as to whether the beneficial effect on reduced bleeding outweighs a possible increased risk of thrombotic complications. Debate will continue until we have the results of definitive large randomized trials powered to detect a clinically important effect on outcome.

KW - Antifibrinolytics

KW - Aprotinin

KW - Bias

KW - Evidence

UR - http://www.scopus.com/inward/record.url?scp=40949097808&partnerID=8YFLogxK

M3 - Article

VL - 39

SP - 308

EP - 310

JO - Journal of Extra-Corporeal Technology

JF - Journal of Extra-Corporeal Technology

SN - 0022-1058

IS - 4

ER -