Anticoagulants, Atrial Fibrillation, Venous Thromboembolism
Conditions
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
The intervention included access to a system to measure processes of care relevant to warfarin management, along with targeted audit and feedback.
Sponsors
Study design
Eligibility
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
| Measure | Time frame | Description |
|---|---|---|
| Percent Change in Time in Therapeutic Range (TTR) | Baseline and 4 years | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Gaps in Monitoring Per Patient-year Among Patients Receiving Anticoagulation With Warfarin | Baseline and 4 years | 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. |
| Change in Percentage of Patients With Follow-up Within 7 Days After a High INR Value (>4.0) | Baseline and 4 years | 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. |
| Change in Percentage of Patients With Follow-up Within 7 Days After a Low INR Value (1.5 or Lower) | Baseline and 4 years | 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. |
| Percentage of Patients With Mean INR Value Between 2.3 - 2.7 | Baseline and 4 years | 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. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| 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 |
| Total | 188,008 |
Baseline characteristics
| Characteristic | Intervention Group | Control Group | Total |
|---|---|---|---|
| Age, Continuous | 77.7 years STANDARD_DEVIATION 11 | 75.3 years STANDARD_DEVIATION 11.2 | 75.4 years STANDARD_DEVIATION 11.2 |
| Average TTR | 66.4 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-year | 0.31 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 days | 50 percentage of instances | 42 percentage of instances | 42 percentage of instances |
| Percentage of instances where INR<=1.5 was followed by a second INR within 7 days | 36 percentage of instances | 28 percentage of instances | 28 percentage of instances |
| Percentage of patients whose mean INR value was between 2.3 and 2.7 | 50 percentage of patients | 47 percentage of patients | 47 percentage of patients |
| Sex: Female, Male Female | 181 Participants | 4340 Participants | 4521 Participants |
| Sex: Female, Male Male | 7848 Participants | 175639 Participants | 183487 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 0 | 0 / 0 |
| serious Total, serious adverse events | 0 / 0 | 0 / 0 |
Outcome results
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.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Intervention Group | Percent Change in Time in Therapeutic Range (TTR) | 2.8 percent change |
| Control Group | Percent Change in Time in Therapeutic Range (TTR) | 0.5 percent change |
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
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Intervention Group | Change in Gaps in Monitoring Per Patient-year Among Patients Receiving Anticoagulation With Warfarin | -0.03 gaps per patient year | Standard Deviation 0.1 |
| Control Group | Change in Gaps in Monitoring Per Patient-year Among Patients Receiving Anticoagulation With Warfarin | -0.01 gaps per patient year | Standard Deviation 0.09 |
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
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Intervention Group | Change in Percentage of Patients With Follow-up Within 7 Days After a High INR Value (>4.0) | 15 percentage change |
| Control Group | Change in Percentage of Patients With Follow-up Within 7 Days After a High INR Value (>4.0) | 0 percentage change |
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
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Intervention Group | Change in Percentage of Patients With Follow-up Within 7 Days After a Low INR Value (1.5 or Lower) | 15 percentage change |
| Control Group | Change in Percentage of Patients With Follow-up Within 7 Days After a Low INR Value (1.5 or Lower) | 2 percentage change |
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
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Intervention Group | Percentage of Patients With Mean INR Value Between 2.3 - 2.7 | 6 percentage change |
| Control Group | Percentage of Patients With Mean INR Value Between 2.3 - 2.7 | 1 percentage change |