Evidence map›Paper›PMID 31189630›Full record

ArticleCanadian family physician Medecin de famille canadien2019

Quality of warfarin management in primary care: Determining the stability of international normalized ratios using a nationally representative prospective cohort.

Sharon Liu, Alexander Singer, Finlay A McAlister, William Peeler, Balraj S Heran, Neil Drummond, Donna P Manca, G Michael Allan, Christina Korownyk, Michael R Kolber and 2 more

Abstract readEvaluation Study
PubMed Full text at PMC
In one paragraph

Article in Canadian family physician Medecin de famille canadien, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
8citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

8 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
  2. Trial
  3. Article
  4. Article
  5. Observational
  6. Quality of warfarin management.Canadian family physician Medecin de famille canadien · 2019
    Article
  7. Warfarin management in primary care.Canadian family physician Medecin de famille canadien · 2019
    Article
  8. Article
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

12 authors.

Sharon LiuMedical student in the Faculty of Medicine at the University of Alberta in Edmonton.
Alexander SingerFamily physician, Associate Professor in the Department of Family Medicine at the University of Manitoba in Winnipeg, and Director of the Manitoba Primary Care Research Network.
Finlay A McAlisterProfessor in the Division of General Internal Medicine at the University of Alberta and lead for the Alberta SPOR (Support for Patient Oriented Research) Data Platform.
William PeelerData Manager with the Manitoba Primary Care Research Network.
Balraj S HeranResearch Associate with the Therapeutics Initiative in the Department of Anesthesiology, Pharmacology, and Therapeutics at the University of British Columbia in Vancouver.
Neil DrummondProfessor and holds the Alberta Health Services Chair in Primary Care Research in the Department of Family Medicine at the University of Alberta.
Donna P MancaDirector of Research in the Department of Family Medicine Research Program at the University of Alberta.
G Michael AllanFamily physician, Director of Programs and Practice Support at the College of Family Physicians of Canada, and Professor in the Department of Family Medicine at the University of Alberta.
Christina KorownykFamily physician and Associate Professor in the Department of Family Medicine and lead for the PEER Knowledge Translation team at the University of Alberta.
Michael R KolberFamily physician, Professor in the Department of Family Medicine at the University of Alberta, and Director of Emprss (Electronic Medical Procedure Reporting Systems).
Michelle GreiverFamily physician at North York General Hospital in Toronto, Associate Professor in the Department of Family and Community Medicine at the University of Toronto, and CPCSSN Network Director for UTOPIAN (University of Toronto Practice-Based Research Network).
Scott R GarrisonFamily physician, Associate Professor in the Department of Family Medicine at the University of Alberta, and Director of the Pragmatic Trials Collaborative (Multi-Provincial Practice-Based Research Network). scott.garrison@ualberta.ca.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectiveTo determine the stability of warfarin anticoagulation using a nationally representative sample of Canadian primary care patients and providers.

designProspective cohort study.

settingPrimary care practices associated with the Canadian Primary Care Sentinel Surveillance Network.

participantsAdult warfarin users with 7 or more evaluable international normalized ratio (INR) readings. MAIN OUTCOMES MEASURES: International normalized ratio time in therapeutic range (TTR) determined using the Rosendaal method; TTR above 75% was considered good INR control and TTR below 60% was considered poor INR control. The primary outcome was the proportion of all warfarin users (using an INR target range of 2.0 to 3.5) with good INR control during their first year taking warfarin who have poor INR control the following year. Secondary outcomes included the TTR using an INR target of 2.0 to 3.0 when restricted to patients with known atrial fibrillation (AF) or venous thromboembolism (VTE); and the proportion of INR values below the target of 2.0 and above the targets of 3.0 and 3.5 in the year before the availability of other oral anticoagulants.

resultsAmong 18 303 adult warfarin users (mean age of 71.0 years, 46.6% female), the median TTR (INR target range of 2.0 to 3.5) was 77.4% (interquartile range of 64.6% to 86.4%). The TTR was above 75% in 56.0% of patients and below 60% in 19.3% of patients. Of those exhibiting good INR control in year 1 of anticoagulation therapy, only 10.2% had poor control the following year. When restricted to patients with known AF or VTE (89.7% with AF and 13.5% with VTE), and assuming an INR target range of 2.0 to 3.0, the TTR was 67.8% (interquartile range of 54.8% to 77.9%). Of these patients, 27.9% had INR values below 2.0, and 19.4% and 8.6% had values above 3.0 and 3.5, respectively.

conclusionPrimary care warfarin management produces a TTR comparable to that in randomized trials, with out-of-range INR values 3 times more likely to predispose to thrombosis (INR of < 2.0) than to hemorrhage (INR of > 3.5). A history of good INR control does predict future INR stability and meaningfully informs decisions to switch established warfarin users onto newer agents.

Indexed as

AgedAged, 80 and overAnticoagulantsAtrial FibrillationCanadaFemaleHemorrhageHumansInternational Normalized RatioMaleMiddle AgedPrevalencePrimary Health CareProspective StudiesStrokeVenous ThromboembolismAnticoagulantsWarfarin

Identifiers

PMID31189630
PMCPMC6738378

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.