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Improving Anticoagulation Control in VISN 1

Improving Anticoagulation Control in VISN 1

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01653405
Enrollment
1260576
Registered
2012-07-31
Start date
2014-10-01
Completion date
2016-09-30
Last updated
2019-04-16

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Anticoagulants, Atrial Fibrillation, Venous Thromboembolism

Keywords

anticoagulants, pharmacists, quality improvement, quality of health care

Brief summary

Over 100,000 VHA patients receive anticoagulants (blood thinners) each year to prevent blood clots (including strokes). Too much anticoagulation increases the risk of serious or even fatal bleeding, and too little anticoagulation fails to protect the patient against blood clots. VHA anticoagulation clinics vary widely on how much time their patients spend in the therapeutic range, the range within which they are protected from clots but not at excessive risk of bleeding. Anticoagulation clinics can improve anticoagulation control by following several relatively simple procedures, including following-up promptly when patients are out of range and focusing on educating and supporting patients with poor control. In this study, the investigators will promote these practices at the anticoagulation clinics of the New England VA region, with a goal of improving anticoagulation control.

Detailed description

Background: Over 100,000 VA patients receive oral anticoagulation (AC) each year to prevent blood clots, including strokes. AC is safer and more effective when it is managed skillfully and therefore well-controlled. AC control can be measured using percent time in therapeutic range (TTR), the proportion of time when patients are sufficiently anticoagulated to prevent clots but not excessively anticoagulated (which increases the risk of bleeding). The investigators have shown that the anticoagulation clinics (ACCs) of the VA vary widely on TTR, from 40% (very poor control) to 70% (excellent control). Improving TTR in the VA would prevent thousands of adverse events, including strokes, major hemorrhages, and deaths. The investigators have further investigated the structures and processes of care that contribute to these wide disparities in TTR performance. Objectives: We applied proven methods to change provider behavior. The goal was to facilitate the adoption of these evidence-based practices in order to improve TTR in VISN 1. We utilized educational outreach, audit and feedback, internal facilitation, and external facilitation to promote improvements in three evidence-based processes of care; namely, follow-up within 7 days after deranged INR values, minimizing loss to follow-up, and use of guideline concordant INR targets. Methods: Our clinician-focused intervention used a Dashboard to measure site-level TTR and processes of care and an Algorithm for routine AC management. Both the Dashboard and the Algorithm are concrete representations of our main evidence-based recommendations to improve AC management. We promoted their use through quarterly visits to the sites, at which we delivered audit and feedback and educational outreach, and also provided external facilitation to address ways to improve these performance measures. Our main outcome was change in site TTR over time, which was compared between VISN 1 and non-VISN 1 sites using an interrupted time series. Secondary outcomes included site-level changes in processes of anticoagulation care (measured using automated data). We used a difference-in-differences (DID) model to examine changes in anticoagulation control, measured as percent time in target range (TTR), as well as process measures, and compared VISN 1 sites to 116 VA sites located outside VISN 1. The pre-intervention period was from 5/1/10-5/1/13, while the post-intervention period was from 5/2/13-5/10/16.

Interventions

OTHERMultifaceted behavioral intervention

The intervention included access to a system to measure processes of care relevant to warfarin management, along with targeted audit and feedback.

Sponsors

VA Office of Research and Development
Lead SponsorFED

Study design

Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
HEALTH_SERVICES_RESEARCH
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
21 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* All patients receiving long-term oral anticoagulation with warfarin within the VA New England Region (VISN 1)

Exclusion criteria

* Patients with valvular heart disease, who may have an INR target range other than 2-3. This usually represents between 10-15% of patients receiving anticoagulation.

Design outcomes

Primary

MeasureTime frameDescription
Percent Change in Time in Therapeutic Range (TTR)Baseline and 4 yearsWe compared TTR after the intervention to before the intervention. We used a difference in differences analysis to compare the absolute percentage change over time in the intervention group vs. the control group.

Secondary

MeasureTime frameDescription
Change in Gaps in Monitoring Per Patient-year Among Patients Receiving Anticoagulation With WarfarinBaseline and 4 yearsWe compared the rate of 56-day gaps per patient year in the pre-intervention and post-intervention period. We used a difference in differences analysis to compare the intervention and control group. We are reporting absolute change.
Change in Percentage of Patients With Follow-up Within 7 Days After a High INR Value (>4.0)Baseline and 4 yearsWe compared the percentage of patients with follow-up within 7 days before and after the intervention. We used a difference in differences analysis to compare the intervention and control groups.
Change in Percentage of Patients With Follow-up Within 7 Days After a Low INR Value (1.5 or Lower)Baseline and 4 yearsWe compared the percentage of patients before and after the intervention. We used a difference in differences analysis to compare the intervention and control groups. Absolute percentage is reported.
Percentage of Patients With Mean INR Value Between 2.3 - 2.7Baseline and 4 yearsWe compared the absolute percentage of patients with a mean INR of 2.3 - 2.7 before and after the intervention. We used a difference in differences analysis to compare the intervention and control groups.

Countries

United States

Participant flow

Participants by arm

ArmCount
Intervention Group
VA patients receiving anticoagulation clinic services at 8 sites in VISN 1.
8,029
Control Group
VA patients receiving anticoagulation clinic services at 116 sites outside of VISN 1.
179,979
Total188,008

Baseline characteristics

CharacteristicIntervention GroupControl GroupTotal
Age, Continuous77.7 years
STANDARD_DEVIATION 11
75.3 years
STANDARD_DEVIATION 11.2
75.4 years
STANDARD_DEVIATION 11.2
Average TTR66.4 percentage of time in target INR range
STANDARD_DEVIATION 3.4
65.9 percentage of time in target INR range
STANDARD_DEVIATION 3.7
65.9 percentage of time in target INR range
STANDARD_DEVIATION 3.7
Gaps in monitoring per patient-year0.31 gaps per patient-year
STANDARD_DEVIATION 0.15
0.37 gaps per patient-year
STANDARD_DEVIATION 0.18
0.37 gaps per patient-year
STANDARD_DEVIATION 0.18
Percentage of instances where an INR >= 4.0 was followed by a second INR within 7 days50 percentage of instances42 percentage of instances42 percentage of instances
Percentage of instances where INR<=1.5 was followed by a second INR within 7 days36 percentage of instances28 percentage of instances28 percentage of instances
Percentage of patients whose mean INR value was between 2.3 and 2.750 percentage of patients47 percentage of patients47 percentage of patients
Sex: Female, Male
Female
181 Participants4340 Participants4521 Participants
Sex: Female, Male
Male
7848 Participants175639 Participants183487 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
— / —— / —
other
Total, other adverse events
0 / 00 / 0
serious
Total, serious adverse events
0 / 00 / 0

Outcome results

Primary

Percent Change in Time in Therapeutic Range (TTR)

We compared TTR after the intervention to before the intervention. We used a difference in differences analysis to compare the absolute percentage change over time in the intervention group vs. the control group.

Time frame: Baseline and 4 years

Population: Patients receiving care at specified sites. Patient-level analyses were aggregated to the site level.

ArmMeasureValue (NUMBER)
Intervention GroupPercent Change in Time in Therapeutic Range (TTR)2.8 percent change
Control GroupPercent Change in Time in Therapeutic Range (TTR)0.5 percent change
p-value: <0.001Difference in differences
Secondary

Change in Gaps in Monitoring Per Patient-year Among Patients Receiving Anticoagulation With Warfarin

We compared the rate of 56-day gaps per patient year in the pre-intervention and post-intervention period. We used a difference in differences analysis to compare the intervention and control group. We are reporting absolute change.

Time frame: Baseline and 4 years

ArmMeasureValue (MEAN)Dispersion
Intervention GroupChange in Gaps in Monitoring Per Patient-year Among Patients Receiving Anticoagulation With Warfarin-0.03 gaps per patient yearStandard Deviation 0.1
Control GroupChange in Gaps in Monitoring Per Patient-year Among Patients Receiving Anticoagulation With Warfarin-0.01 gaps per patient yearStandard Deviation 0.09
p-value: 0.43test of differences
Secondary

Change in Percentage of Patients With Follow-up Within 7 Days After a High INR Value (>4.0)

We compared the percentage of patients with follow-up within 7 days before and after the intervention. We used a difference in differences analysis to compare the intervention and control groups.

Time frame: Baseline and 4 years

ArmMeasureValue (NUMBER)
Intervention GroupChange in Percentage of Patients With Follow-up Within 7 Days After a High INR Value (>4.0)15 percentage change
Control GroupChange in Percentage of Patients With Follow-up Within 7 Days After a High INR Value (>4.0)0 percentage change
p-value: <0.001difference in differences
Secondary

Change in Percentage of Patients With Follow-up Within 7 Days After a Low INR Value (1.5 or Lower)

We compared the percentage of patients before and after the intervention. We used a difference in differences analysis to compare the intervention and control groups. Absolute percentage is reported.

Time frame: Baseline and 4 years

ArmMeasureValue (NUMBER)
Intervention GroupChange in Percentage of Patients With Follow-up Within 7 Days After a Low INR Value (1.5 or Lower)15 percentage change
Control GroupChange in Percentage of Patients With Follow-up Within 7 Days After a Low INR Value (1.5 or Lower)2 percentage change
p-value: <0.001Difference in differences
Secondary

Percentage of Patients With Mean INR Value Between 2.3 - 2.7

We compared the absolute percentage of patients with a mean INR of 2.3 - 2.7 before and after the intervention. We used a difference in differences analysis to compare the intervention and control groups.

Time frame: Baseline and 4 years

ArmMeasureValue (NUMBER)
Intervention GroupPercentage of Patients With Mean INR Value Between 2.3 - 2.76 percentage change
Control GroupPercentage of Patients With Mean INR Value Between 2.3 - 2.71 percentage change
p-value: 0.002difference in differences

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026