Warfarin Dosing Algorithms Underpredict Dose Requirements in Patients Requiring ≥7 mg Daily: A Systematic Review and Meta-analysis.
There is preliminary evidence to suggest that some published warfarin dosing algorithms produce biased maintenance dose predictions in patients who require higher than average doses. We conducted a meta-analysis of warfarin dosing algorithms to determine if there exists a systematic under- or overprediction of dose requirements for patients requiring ≥7 mg/day across published algorithms. Medline and Embase databases were searched up to September 2015. We quantified the proportion of over- and underpredicted doses in patients whose observed maintenance dose was ≥7 mg/day. The meta-analysis included 47 evaluations of 22 different warfarin dosing algorithms from 16 studies. The meta-analysis included data from 1,492 patients who required warfarin doses of ≥7 mg/day. All 22 algorithms were found to underpredict warfarin dosing requirements in patients who required ≥7 mg/day by an average of 2.3 mg/day with a pooled estimate of underpredicted doses of 92.3% (95% confidence interval 90.3-94.1, I2= 24%).
School of Pharmacy, University of Otago, Dunedin, New Zealand.|Faculty of Pharmacy, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
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Saffian
School of Pharmacy, University of Otago, Dunedin, New Zealand.
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Duffull
School of Pharmacy, University of Otago, Dunedin, New Zealand.
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Wright
D000465:Algorithms; D000925:Anticoagulants / Q000008:administration & dosage*; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D006801:Humans; D011237:Predictive Value of Tests; D014859:Warfarin / Q000008:administration & dosage*
D000925:Anticoagulants; D014859:Warfarin