Chest
Original Research: AnticoagulationEffect of Study Setting on Anticoagulation Control: A Systematic Review and Metaregression
Section snippets
Search Strategy and Study Inclusion Criteria
We searched the MEDLINE database using the search strategy shown in Appendix 1. The rest of our search strategy, along with its outcome, is illustrated in Figure 1. Studies were included if they contained original data measuring anticoagulation control in at least one patient group over time. This required the calculation of serial INRs on each person and an interpolation of the values between actual measures so that anticoagulation status could be determined on each day of observation. We
Results
The MEDLINE search retrieved 1,835 citations (Appendix 1), of which 190 appeared to study anticoagulation monitoring (Fig 1). A total of 79 of these articles studied anticoagulation control using a patient-time approach. We identified a further 39 articles from alternative sources including Embase (n = 8), Web of Science (n = 13), and hand searching (n = 18). Of the resulting 118 articles, we excluded 51 because the INR measures were not used to assess anticoagulation (n = 7), a target INR
Discussion
To our knowledge, this is the first systematic review and metaregression of studies measuring anticoagulation control. We found a large number of studies that used a patient-time approach to measure the percentage of time in a typical therapeutic target range. The overall percentage of time spent in the therapeutic range was 63.5% (95% CI, 61.6 to 65.6%). However, anticoagulation control varied extensively among study groups, with study setting, drug type, and self-monitoring being the most
Appendix 1: medline research strategy for study
- 1
acenocoumarol.mp. or ACENOCOUMAROL/ (825)
- 2
dicumarol.mp. or DICUMAROL/ (1310)
- 3
ethyl biscoumacetate.mp. or Ethyl Biscoumacetate/ (163)
- 4
phenprocoumon.mp. or PHENPROCOUMON/ (705)
- 5
Warfarin.mp. or WARFARIN/ (11151)
- 6
ADMINISTRATION, ORAL/or oral.mp. (301044)
- 7
1 or 2 or 3 or 4 or 5 or 6 (312429)
- 8
*ANTICOAGULANTS/ (15843)
- 9
INR.mp. or International Normalized Ratio/ (2675)
- 10
international normalized ratio.mp. (2104)
- 11
9 or 10 (3108)
- 12
prothrombin time.mp. or Prothrombin Time/ (9487)
- 13
PT.mp. (12621)
- 14
PTR.mp. (340)
- 15
12 or 13 or 14
Acknowledgment
We thank Steve Doucette for his help with the analyses and Dr. Phillip Wells for reviewing previous drafts of this study.
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This study was supported in part by Institute for Safe Medication Practices Canada. Dr. Forster was an Ontario Ministry of Health Career Scientist when this study was conducted. No authors have conflicts of interest to disclose.
Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal.org/misc/reprints.shtml).