Anticoagulation
Conditions
Keywords
International Normalized Ratio, Warfarin
Brief summary
The purpose of this study is to determine the feasibility, safety, and acceptability of implementing an extended interval of INR follow-up in Veterans on a stable dose of warfarin in the Anticoagulation Clinic at the William S. Middleton Memorial Veterans Hospital. All participants will be provided usual care from the anticoagulation clinic, except for the interval between INRs. If the participant continues to be on a stable dose of warfarin and the INRs are within the goal range of 2-3 (including lab variation), follow-up visits will be scheduled following an extended interval protocol. Patient satisfaction will be evaluated at various points throughout the study. Additionally provider satisfaction, confidence, and knowledge of the extended interval protocol will be analyzed. Bleeding and thromboembolic events will be evaluated to ensure the safety of an extended follow-up interval.
Detailed description
The purpose of this study is to determine the feasibility, safety, and acceptability of implementing an extended interval of INR follow-up in Veterans on a stable dose of warfarin in the Anticoagulation Clinic at the William S. Middleton Memorial Veterans Hospital. All participants will be provided usual care from the anticoagulation clinic, except for the interval between INRs. If the participant continues to be on a stable dose of warfarin and the INRs are within the goal range of 2-3 (including lab variation), follow-up visits will be scheduled following an extended interval protocol, from 5-6 weeks, to 7-8 weeks, to 11-12 weeks and then continued with 11-12 week visits if INRs continue to remain in goal range and appropriate for the patient. Patient satisfaction will be evaluated at baseline, 6-, 12-, and 24-months. Additionally provider satisfaction, confidence, and knowledge of the extended interval protocol will be analyzed. Bleeding and thromboembolic events will be evaluated to ensure the safety of an extended follow-up interval.
Interventions
DRUGWarfarin
If the patient's INRs stay within goal range, their interval of INR follow-up will be extended based on a protocol to a maximum of 12 weeks.
Sponsors
University of Wisconsin, Madison
William S. Middleton Memorial Veterans Hospital
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* 18 years of age or older * requirement for indefinite warfarin therapy * target INR of 2-3 * stable weekly warfarin dose for the past 6 months (not more than a single, one-time adjustment (boost/omission) in the past 6 months, planned interruption for a procedure or surgery with INR(s) out of range in the past 6 months would not exclude a patient) * a patient of the Madison VA anticoagulation clinic for the previous 12 months
Exclusion criteria
* consistently drink ≥4 alcoholic beverages/day or a documented episode of alcohol binging in the past 6 months * diagnosis of cancer and on active chemotherapy/radiotherapy in the past 3 months * life expectancy of \< 1 year * enrolled in other investigational drug protocols * only receiving anticoagulation care at the Madison VA for part of the year (e.g. snowbirds) * receiving visiting nurse services for INR monitoring * thrombocytopenia (\<100K) within past 12 months * history of bleeding or thromboembolism requiring medical intervention within past 6 months * treatment for active liver disease (e.g. hepatitis) * diagnosis or documentation in EMR suggesting cognitive impairment * activated power of attorney * inability to provide informed consent * non-English speaking * unstable mental health disorder that impairs judgment * history of non-adherence to anticoagulation clinic policies and procedures (i.e. missed appointments, self-adjustment of warfarin dose, nonadherence, etc.).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of Participants Scheduled for at Least 4 Consecutive 12-week Intervals | 24 months | The outcome will determine the number of participants scheduled for at least 4 consecutive 12-week intervals |
| Rates of Participant Accrual | up to 2.25 years | Number of participants who enroll vs. number of individuals invited |
| Number of Participants Able to be Scheduled for at Least One 12-week Interval | 24 months | This outcome will determine the number of participants able to be scheduled for at least one 12-week interval |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Time in Therapeutic Range From Baseline | 6, 12, and 24 months | The outcome will evaluate the change in time in therapeutic range (TTR) from baseline (intention-to-treat) |
| Patient Satisfaction Through Total DASS Score | baseline, 6 months, 12 months, 24 months | Patient satisfaction through total DASS score. DASS = Duke Anticoagulation Satisfaction Scale. 25-item scale.Higher numbers indicate worsening satisfaction ranging from 25-175. Seven-point ordinal scale (not at all = 1, very much = 7). |
| Change in Frequency of Appointments From Baseline to End of Study | 12 and 24 months | This outcome will evaluate the change in frequency of appointments from baseline to end of study (at 12 and 24 months) |
| Bleeding and Thromboembolic Events From Baseline | 24 months | This outcome will determine the number of bleeding and thromboembolic events from baseline |
Other
| Measure | Time frame | Description |
|---|---|---|
| Frequency and Type of Protocol Deviations From Both Participants and Study Staff | Up to 2.25 years | This outcome determines the frequency and type of protocol deviations from both participants and study staff |
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Intervention Arm All patients in the study will be in the intervention arm.
Warfarin: If the patient's INRs stay within goal range, their interval of INR follow-up will be extended based on a protocol to a maximum of 12 weeks. | 50 |
| Total | 50 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | admitted to skilled nursing facility | 3 |
| Overall Study | bleeding event | 1 |
| Overall Study | discontinuation of warfarin | 3 |
| Overall Study | INR goal range changed | 1 |
| Overall Study | INRs drawn by visiting nurse services | 1 |
| Overall Study | transferred care to another doctor | 2 |
Baseline characteristics
| Characteristic | Intervention Arm |
|---|---|
| Age, Continuous | 71.4 years STANDARD_DEVIATION 7.6 |
| HAS-BLED score | 1.8 units on a scale STANDARD_DEVIATION 0.9 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 1 Participants |
| Race (NIH/OMB) White | 49 Participants |
| Region of Enrollment United States | 50 participants |
| Sex: Female, Male Female | 1 Participants |
| Sex: Female, Male Male | 49 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 50 |
| other Total, other adverse events | 19 / 50 |
| serious Total, serious adverse events | 15 / 50 |
Outcome results
Primary
Number of Participants Able to be Scheduled for at Least One 12-week Interval
This outcome will determine the number of participants able to be scheduled for at least one 12-week interval
Time frame: 24 months
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Intervention Arm | Number of Participants Able to be Scheduled for at Least One 12-week Interval | 36 Participants |
Primary
Number of Participants Scheduled for at Least 4 Consecutive 12-week Intervals
The outcome will determine the number of participants scheduled for at least 4 consecutive 12-week intervals
Time frame: 24 months
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Intervention Arm | Number of Participants Scheduled for at Least 4 Consecutive 12-week Intervals | 15 Participants |
Primary
Rates of Participant Accrual
Number of participants who enroll vs. number of individuals invited
Time frame: up to 2.25 years
Population: 107 invited to participate in the study, not all enrolled or started the study
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Intervention Arm | Rates of Participant Accrual | Number of patients invted | 107 Participants |
| Intervention Arm | Rates of Participant Accrual | Patient enrolled in study | 51 Participants |
| Intervention Arm | Rates of Participant Accrual | Patients analyzed for study | 50 Participants |
Secondary
Bleeding and Thromboembolic Events From Baseline
This outcome will determine the number of bleeding and thromboembolic events from baseline
Time frame: 24 months
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Intervention Arm | Bleeding and Thromboembolic Events From Baseline | Number of thromboembolic events | 2 events |
| Intervention Arm | Bleeding and Thromboembolic Events From Baseline | Number of major bleeding events | 6 events |
| Intervention Arm | Bleeding and Thromboembolic Events From Baseline | Number of serious bleeding events | 16 events |
Secondary
Change in Frequency of Appointments From Baseline to End of Study
This outcome will evaluate the change in frequency of appointments from baseline to end of study (at 12 and 24 months)
Time frame: 12 and 24 months
Population: 44 participants remained in the study at 12 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Intervention Arm | Change in Frequency of Appointments From Baseline to End of Study | Planned anticoagulation visits (baseline) | 12.67 visits per 12 months | Standard Deviation 2.56 |
| Intervention Arm | Change in Frequency of Appointments From Baseline to End of Study | Planned anticoagulation visits (0-12 months) | 10.43 visits per 12 months | Standard Deviation 3.58 |
Secondary
Change in Time in Therapeutic Range From Baseline
The outcome will evaluate the change in time in therapeutic range (TTR) from baseline (intention-to-treat)
Time frame: 6, 12, and 24 months
Population: 49 participants at 12 months, 44 participants at 24 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Intervention Arm | Change in Time in Therapeutic Range From Baseline | 6 months | -12.2 change in percentage of TTR | Standard Deviation 26.4 |
| Intervention Arm | Change in Time in Therapeutic Range From Baseline | 12 months | -7.3 change in percentage of TTR | Standard Deviation 18.3 |
| Intervention Arm | Change in Time in Therapeutic Range From Baseline | 24 months | -4.4 change in percentage of TTR | Standard Deviation 13.2 |
Secondary
Patient Satisfaction Through Total DASS Score
Patient satisfaction through total DASS score. DASS = Duke Anticoagulation Satisfaction Scale. 25-item scale.Higher numbers indicate worsening satisfaction ranging from 25-175. Seven-point ordinal scale (not at all = 1, very much = 7).
Time frame: baseline, 6 months, 12 months, 24 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Intervention Arm | Patient Satisfaction Through Total DASS Score | baseline | 42.89 score on a scale | Standard Deviation 12.08 |
| Intervention Arm | Patient Satisfaction Through Total DASS Score | 6 months | 43.99 score on a scale | Standard Deviation 11.75 |
| Intervention Arm | Patient Satisfaction Through Total DASS Score | 12 months | 38.83 score on a scale | Standard Deviation 11.53 |
| Intervention Arm | Patient Satisfaction Through Total DASS Score | 24 months | 46.82 score on a scale | Standard Deviation 15.16 |
Other Pre-specified
Frequency and Type of Protocol Deviations From Both Participants and Study Staff
This outcome determines the frequency and type of protocol deviations from both participants and study staff
Time frame: Up to 2.25 years
Population: 634 eligible participant visits
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Intervention Arm | Frequency and Type of Protocol Deviations From Both Participants and Study Staff | extended interval visits scheduled correctly | 94.3 percentage of visits |
| Intervention Arm | Frequency and Type of Protocol Deviations From Both Participants and Study Staff | Deviations too short | 3.0 percentage of visits |
| Intervention Arm | Frequency and Type of Protocol Deviations From Both Participants and Study Staff | Deviations too long | 2.7 percentage of visits |