A meta-analysis and metaregression analysis of recent data on oral anticoagulation (INR) management using portable prothrombin systems Monica Cepoiu-Martin, Sarah Rose , Diane Lorenzetti, Ken Fyie,

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Transcript A meta-analysis and metaregression analysis of recent data on oral anticoagulation (INR) management using portable prothrombin systems Monica Cepoiu-Martin, Sarah Rose , Diane Lorenzetti, Ken Fyie,

Slide 1

A meta-analysis and metaregression analysis of recent
data on oral anticoagulation
(INR) management using
portable prothrombin
systems
Monica Cepoiu-Martin, Sarah Rose , Diane Lorenzetti,
Ken Fyie, Tom Noseworthy, Lloyd Sutherland
University of Calgary
Centre for Health and Policy Studies (CHAPS)


Slide 2

Supported by a financial contribution from
Albert Health Services through Alberta
Health Technologies Decision Process: the
Alberta model for technology assessment
and policy analysis.

ACKNOWLEDGMENTS


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The views expressed herein do not
necessarily represent the official policy of
Alberta Health Services.

DISCLAMER


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PPTS PORTABLE PROTHROMBIN SYSTEMS
INR
INTERNATIONAL NORMALIZED RATIO
OAT ORAL ANTICOAGULATION THERAPY
RCTs RANDOMIZED CONTROLLED TRIALS
OR
ODDS RATIO
SMD STANDARDIZED MEAN DIFFERENCE

ABBREVIATIONS


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Long-term OAT is indicated in patients
suffering from clotting disorders.



The most widely used agents for OAT are
vitamin K antagonists.



Clotting or hemorrhages are life
threatening complications of inadequate
OAT.

ORAL ANTICOAGULATION


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The prothrombin time, expresses as INR,
is the best indicator of the intensity of
anticoagulation.



Generally, the INR reflecting optimal
anticoagulation is between 2 and 3.



INR monitoring and OAT doseadjustments have to be performed
regularly.

INR MONITORING


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The current gold-standard method for
monitoring the INR is laboratory testing
of blood obtained by venipuncture.

Disadvantages:
 Results are not available on the spot
 Patients have to travel regularly
 Costly

USUAL CARE


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PPTS measure INR outside the laboratory
setting.
Advantages:
 Results are available in 3 minutes
 Venipuncture is not necessary
 Self-testing and self-management are
possible

NEW TECHNOLOGY


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What is the effectiveness and safety of
PPTS compared to usual care?



What are the factors that may increase or
decrease the effectiveness of PPTS in
monitoring oral anticoagulation?

RESEARCH QUESTIONS


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Studies included: 22 RCTs (24 papers)
Publication date: 1989-2009
Sources:
 Electronic databases: MEDLINE, Cochrane
Library, EMBASE, HTA Database –
University of York, DARE.
 Gray literature
 Reference lists

LITERATURE SEARCH


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Selection criteria:
 Patients on OAT for at least 3 months
 PPTS testing vs usual care
 Outcomes reported:





% time in INR range
% INR measurements in range
Rates of major or minor hemorrhage
Rates of major and minor thromboembolic
events

SELECTION OF THE LITERATURE


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Qualitative analysis
 CONSORT statement checklist
Quantitative analysis
 Pooled standardized mean differences
 Summary OR
 Chi-square heterogeneity test
 Meta-regression analysis
 Statistical program: STATA version 9.0

DATA ANALYSIS


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Type of intervention: PPTS patient selftesting, PPTS patient self-management
and POC testing
OAT drug
Patient education
Indications for OAT
Age of the sample
Gender of the sample

HETEROGENEITY VARIABLES


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High variability in patient selection
criteria, follow-up duration, amount of
education for control patients



Variability in the quality of reporting



Lack of consistency in defining and
reporting of clinical outcomes and adverse
events

QUALITATIVE ANALYSIS


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Intervention (PPTS testing) versus Control (usual care)
Outcomes

Pooled
SMD

95% CI

Mean % time in INR range

0.156*

0.032 – 0.280

Mean % INR measurements in range

0.317*

0.190 – 0.444

Pooled OR

95% CI

Major hemorrhagic events

0.677*

0.460 – 0.995

Major thromboembolic events

0.526*

0.377 – 0.733

Adverse events

*Statistically significant (p<0.05)

META-ANALYSIS


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Age of the sample: studies that included
only elderly patients reported better
clinical outcomes.



Oral anticoagulation management:
studies that used self-testing or selfmanagement in the intervention group
reported better clinical outcomes.

META-REGRESSION ANALYSIS


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Great variability in methods between RCTs



Relatively low quality of RCTs



Patients included in the studies reviewed
were highly selected



Difficult to define meaningful clinical
outcomes

LIMITATIONS


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PPTS testing of INR is at least as effective
as the usual care of patients on OAT.



The incidence of adverse events seems to
be lower in PPTS testing patients.



More research is necessary to determine
the characteristics of the patients that
would benefit the most from PPTS testing.

CONCLUSIONS


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THANK YOU!