Determinants and measures of quality in oral anticoagulation therapy

Vitamin K Antagonist Use and Level of Anticoagulation Control Among Patients at a Tertiary Hospital in Northern Tanzania

BACKGROUND

Vitamin K antagonists (VKA) continue to be the principal anticoagulants for both the treatment and prevention of venous thromboembolism. The use of VKA often requires regular monitoring to avoid over-anticoagulation and prevent thromboembolic complications. The aim was to determine the indication for VKA use and factors associated with suboptimal anticoagulation control among patients in northern Tanzania.

METHODS

This was a retrospective cohort study that examined the anticoagulation data of patients on long-term VKA from 1st January 2020 to 31st December 2022. Eligible participants were those on VKAs for at least 7 days and with at least 3 international normalized ratio (INR) results. The level of anticoagulation control was determined through the calculation of the time-in-therapeutic range (TiTR) using the Rosendaal and the percent of INR in therapeutic range methods.

RESULTS

TiTR was found to be 17% using the direct method and 16% using the Rosendaal formula. 102 tests out of 365 were within the target range (28%). Absence of health insurance (aRR: 1.24, 95% CI: 1.06-1.44, P = .007), alcohol consumption (aRR: 1.37, 95% CI: 1.15-1.62, P < .001), and prolonged intervals between tests of 14 to 28 days (aRR: 1.34, 95% CI: 1.05-1.74, P = .018) showed association with INR being out of range.

CONCLUSION

Patients who achieved target therapeutic anticoagulation control were less than the acceptable 65%. Anticoagulation outcomes were better in patients with frequent INR monitoring and those with health insurance. Alcohol consumption carries a high risk of poor anticoagulation control. Further studies are needed to enforce better INR control.

Anticoagulation control among patients on vitamin K antagonists in nine countries in Sub-Saharan Africa

Vitamin K antagonists (VKA) is the primary anticoagulant in most settings of Sub-Saharan Africa. Understanding the quality of anticoagulation services in the continent is vital in optimising the intended benefits. This study assessed the quality of anticoagulation and associated factors among VKA-treated patients in nine SSA countries. We conducted a retrospective cohort study of randomly selected patients on anticoagulation from 20 clinics in Botswana, the Democratic Republic of Congo, Ethiopia, Gambia, Ghana, Mozambique, Nigeria, Tanzania, and South Africa. Eligible participants were those on VKAs for at least three months and with at least four international normalised ratios (INR) results in 2019-2021. We report the proportion of INR values in the therapeutic range, time-in-therapeutic range (TTR) using the Rosendaal method, and the proportion of patients with TTR ≥ 65% (optimal anticoagulation). The mean age was 51.1(16.1) years, and 64.2% were women. The most common indications for VKA included venous thromboembolism (29.6%), prosthetic valves (26.7%) and atrial fibrillation/flutter (30.1%). We analysed 6743 INR tests from 1011 participants, and of these, 48.5% were sub-therapeutic, 34.1% therapeutic, and 17.4% were supratherapeutic relative to disease-specific reference ranges. TTR was calculated for 660 patients using 4927 INR measurements. The median (interquartile range [IQR]) TTR was 35.8(15.9,57.2) %. Optimal anticoagulation control was evident in 19.2% of participants, varying from 2.7% in Tanzania to 23.1% in Ethiopia. The proportion of patients with TTR ≥ 65% was 15,4% for prosthetic heart valves, 21.1% for venous thromboembolism and 23.7% for atrial fibrillation or flutter. Countries with universal health coverage had higher odds of optimal anticoagulation control (adjusted odds ratio (aOR) 1.79, 95% confidence interval [CI], 1.15- 2.81, p = 0.01). Patients on VKAs for different therapeutic indications in SSA had suboptimal TTR. Universal health coverage increased the odds of achieving TTR by 79%. The evidence calls for more intensive warfarin management strategies in SSA, including providing VKA services without out-of-pocket payments.

Utility of a pharmacist-managed Anticoagulation Program in patients with congenital heart disease

BACKGROUND

Warfarin remains the preferred anticoagulant for many patients with CHD. The complexity of management led our centre to shift from a nurse-physician-managed model with many providers to a pharmacist-managed model with a centralized anticoagulation team. We aim to describe the patient cohort managed by our Anticoagulation Program and evaluate the impact of implementation of this consistent, pharmacist-managed model on time in therapeutic range, an evidence-based marker for clinical outcomes.

METHODS

A single-centre retrospective cohort study was conducted to evaluate the impact of the transition to a pharmacist-managed model to improve anticoagulation management at a tertiary pediatric heart centre. The percent time in therapeutic range for a cohort managed by both models was compared using a paired t-test. Patient characteristics and time in therapeutic range of the program were also described.

RESULTS

After implementing the pharmacist-managed model, the time in therapeutic range for a cohort of 58 patients increased from 65.7 to 80.2% (p < .001), and our Anticoagulation Program consistently maintained this improvement from 2013 to 2022. The cohort of patients managed by the Anticoagulation Program in 2022 included 119 patients with a median age of 24 years (range 19 months-69 years) with the most common indication for warfarin being mechanical valve replacement (n = 81, 68%).

CONCLUSIONS

Through a practice change incorporating a collaborative, centralized, pharmacist-managed model, this cohort of CHD patients on warfarin had a fifteen percent increase in time in therapeutic range, which was sustained for nine years.

Enhancing postoperative anticoagulation therapy with remote patient monitoring: A pilot crossover trial study to evaluate portable coagulometers and chatbots in cardiac surgery follow-up

Objective

Prior research has not assessed the value of remote patient monitoring (RPM) systems for patients undergoing anticoagulation therapy after cardiac surgery. This study aims to assess whether the clinical follow-up through RPM yields comparable outcomes with the standard protocol.

Methods

A crossover trial assigned participants to SOC-RPM or RPM-SOC, starting with the standard of care (SOC) for the first 6 months after surgery and using RPM for the following 6 months, or vice-versa, respectively. During RPM, patients used the Coaguchek© to accurately measure International Normalized Ratio values and a mobile text-based chatbot to report PROs and adjust the therapeutic dosage. The study assessed patients' and clinicians' experience with RPM and compared direct costs.

Results

Twenty-seven patients participated. The median time in therapeutic range (TTR) levels during RPM were 72.2% and 50.6% for the SOC-RPM and RPM-SOC arms, respectively, and during SOC, they were 49.4% and 58.4% for SOC-RPM and RPM-SOC arms, respectively. Patients and the clinical team reported high trust and satisfaction with the proposed digital service. Statistically significant differences were only found in the cost of RPM in the RPM-SOC, which was higher than SOC in the SOC-RPM arm.

Conclusions

Portable coagulometers and chatbots can enhance the remote management of patients undergoing anticoagulation therapy, improving patient experience. This presents a promising alternative to the current standard procedure. The results of this study seem to suggest that RPM may have a higher value when initiated after a SOC period rather than starting RPM immediately after surgery.Trial registration: ClinicalTrials.gov NCT06423521.

Study of Rivaroxaban for Cerebral Venous Thrombosis: A Randomized Controlled Feasibility Trial Comparing Anticoagulation With Rivaroxaban to Standard-of-Care in Symptomatic Cerebral Venous Thrombosis

BACKGROUND

Emerging data suggest that direct oral anticoagulants may be a suitable choice for anticoagulation for cerebral venous thrombosis (CVT). However, conducting high-quality trials in CVT is challenging as it is a rare disease with low rates of adverse outcomes such as major bleeding and functional dependence. To facilitate the design of future CVT trials, SECRET (Study of Rivaroxaban for Cerebral Venous Thrombosis) assessed (1) the feasibility of recruitment, (2) the safety of rivaroxaban compared with standard-of-care anticoagulation, and (3) patient-centered functional outcomes.

METHODS

This was a phase II, prospective, open-label blinded-end point 1:1 randomized trial conducted at 12 Canadian centers. Participants were aged ≥18 years, within 14 days of a new diagnosis of symptomatic CVT, and suitable for oral anticoagulation; they were randomized to receive rivaroxaban 20 mg daily, or standard-of-care anticoagulation (warfarin, target international normalized ratio, 2.0-3.0, or low-molecular-weight heparin) for 180 days, with optional extension up to 365 days. Primary outcomes were annual rate of recruitment (feasibility); and a composite of symptomatic intracranial hemorrhage, major extracranial hemorrhage, or mortality at 180 days (safety). Secondary outcomes included recurrent venous thromboembolism, recanalization, clinically relevant nonmajor bleeding, and functional and patient-reported outcomes (modified Rankin Scale, quality of life, headache, mood, fatigue, and cognition) at days 180 and 365.

RESULTS

Fifty-five participants were randomized. The rate of recruitment was 21.3 participants/year; 57% of eligible candidates consented. Median age was 48.0 years (interquartile range, 38.5-73.2); 66% were female. There was 1 primary event (symptomatic intracranial hemorrhage), 2 clinically relevant nonmajor bleeding events, and 1 recurrent CVT by day 180, all in the rivaroxaban group. All participants in both arms had at least partial recanalization by day 180. At enrollment, both groups on average reported reduced quality of life, low mood, fatigue, and headache with impaired cognitive performance. All metrics improved markedly by day 180.

CONCLUSIONS

Recruitment targets were reached, but many eligible participants declined randomization. There were numerically more bleeding events in patients taking rivaroxaban compared with control, but rates of bleeding and recurrent venous thromboembolism were low overall and in keeping with previous studies. Participants had symptoms affecting their well-being at enrollment but improved over time.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03178864.

Decentralization and Virtualization of INR-based Anticoagulation Control During the COVID-19 Pandemic

OBJECTIVE

To investigate the effectiveness of the decentralization and virtualization of anticoagulation clinics just before and during the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

We conducted a cohort study investigation at Prince Sultan Cardiac Clinics PSCC Qassim region, Saudi Arabia. To evaluate the effectiveness of the virtual coagulation clinic, we calculated the time in therapeutic range (TTR), Morisky score for adherence, and satisfaction. Demographics of the patients were analyzed to group patients based on their regions or districts to facilitate the visits. Thirteen different PHCs/Hospitals were allocated for decentralization based on patient density in that region. Intensive courses were provided for all general practitioners (GPs) regarding warfarin anticoagulation and point of care testing (POCT) using iSTAT. All appointments were scheduled by WhatsApp, with no more actual visits to the main center.

RESULTS

Among the included participants (n = 5616), 61.1% were females, 38.9% were males, and the mean age was 60.5 (18-85) years. The total number of clinic visits was 7303 per month, with an average of 1.3 visits per patient. Approximately 95% of the participants had a valvular indication to receive anticoagulation; of them, 55% underwent mitral valve replacement. Moreover, after the virtualization of the INR clinic, keeping INR levels within a therapeutic range was reported in 80% of patients. Regarding patient satisfaction, 90% of the total population was satisfied by the new experience.

CONCLUSION

Decentralization and virtualization of the INR clinic have similar TTR results if conducted properly.

Vitamin K-dependent anticoagulant use and level of anticoagulation control in sub-Saharan Africa: protocol for a retrospective cohort study

BACKGROUND

Given that vitamin K-dependent anticoagulants (VKAs) will continue to be the primary anticoagulant in Africa for a long time, understanding the quality of anticoagulation services in the continent is vital for optimising the intended benefits. Notably, a few small studies have assessed the quality of anticoagulation in sub-Saharan Africa (SSA) countries. This study will describe the current VKA use and anticoagulation control among patients in selected SSA countries.

METHODS AND ANALYSIS

We plan to review the 2019 anticoagulation data of a cohort of 800 random patients from 19 selected clinics in Botswana, the Democratic Republic of Congo, Ethiopia, Gambia, Ghana, Mozambique, Nigeria, Tanzania and South Africa. We expect at least one participating site to enrol 100 participants in each country. Eligible participants will be those on VKAs for at least 3 months and with at least four international normalised ratio (INR) results. We will document the indications, type and duration of VKA use, sociodemographic factors, coexisting medical conditions, concurrent use of drugs that interact with warfarin and alcohol and tobacco products. The level of anticoagulation control will be determined by calculating the time-in-therapeutic range (TTR) using the Rosendaal and the Percent of INR in TTR methods. A TTR of less than 65% will define a suboptimal anticoagulation control.

ETHICS AND DISSEMINATION

This study was approved by the Ministry of Health and Wellness Ethics Committee (HPDME13/8/1) in Botswana and local research ethics committees or institutional review boards of all participating sites. As the study collects data from existing records, sites applied for waivers of consent. We will disseminate research findings through peer-reviewed scientific publications.

Tele-pharmacy Anticoagulation Clinic During COVID-19 Pandemic: Patient Outcomes

Introduction: It is well-established that clinical pharmacist-managed anticoagulation services achieve superior anticoagulation control, with a positive impact. At King Abdulaziz Medical City (KAMC), Riyadh, Saudi Arabia, the structure of anticoagulation management is a pharmacist-managed specialty service. With the current COVID-19 situation, measures were taken to assure the continuity of patient care by establishing tele-pharmacy anticoagulation clinics. Materials and Methods: This was a prospective study with patients prescribed anticoagulation and followed up for 3 months. Since establishing the anticoagulation virtual clinic in March 2020, 270 patients were recruited in the study. The data collected included age, gender, comorbidities, indication for anticoagulation, intended duration of treatment, warfarin dose, testing of International Normalized Ratio (INR), INR target, range of INR values, time INR that was within the therapeutic range (TTR), and complications of therapy (bleeding and/or bruises). The patients were asked to complete the pharmacist satisfaction survey (PSS) after their consultation to assess patient satisfaction with the new virtual consultation system. Linguistic and cultural validation was conducted for the questionnaire. Results: A total of 270 patients were included in the study. The mean percentage of overall INR values in the range was 59.39% ± 32.84, and the mean time with the overall INR was within the therapeutic range 57.81% ± 32.08. Thirty-one percent of the sample had good anticoagulation control (time in therapeutic range >70%). The median satisfaction score was 32 (IQR 28-36) with a maximum score of 40. Conclusion: This is the first study to assess the tele-pharmacy anticoagulation clinic's efficiency and patient satisfaction in Saudi Arabia during the COVID-19 pandemic. This type of consultation was as effective as face-to-face consultations. The study also highlighted that though the reduction in the cost of care was not substantial, there was a significant increase in resource (clinical pharmacist) utilization as a result of this model. The adoption of tele-pharmacy resulted in time savings for the clinical pharmacists who can be utilized in many other improvement projects in adult ambulatory clinics to ensure the delivery of better quality and safe patient care.

Association between Patients' Knowledge and Adherence to Anticoagulants, and Its Effect on Coagulation Control

BACKGROUND

Warfarin requires strict monitoring by measuring prothrombin time (PT), international normalized ratio (INR), and time in therapeutic range (TTR). Several factors can lead to poor PT/INR control including vitamin K status, medication adherence, knowledge, and quality of life. The present study aims to assess patient adherence to warfarin treatment and its correlation with INR control.

METHODS

A cross-sectional study was conducted between October 2017 and January 2018 at Tripoli University Hospital. Data were collected by structured questionnaires which included; demographic and clinical characteristics, the Oral Anticoagulation Knowledge (OAK) test, and the Morisky Medication Adherence Scale (MMAS-8).

RESULTS

The final analysis included 88 out of 140 patients (73.33%). There were significant differences in age range, gender, marital status, and education level between the 2 groups (poor knowledge and adequate knowledge) (p < 0.05). There was a significant positive correlation between OAK test score and TTR. Overall, 76.2% of patients were adherent to warfarin (MMAS score ≥6) and 20.45% of patients were of high adherence (MMAS score of 8). The median score was 6 (IQR 6-7). A statistically significant, strong positive correlation between adherence to medication and TTR as an indicator of INR control was found (rs[86] = 0.472, p < 0.0001).

CONCLUSION

The study addressed and identified several areas for future improvement of patient outcomes. The implementation of new approaches to enhance patient knowledge and adherence is warranted, and measures to provide treatment for all patients that require it are needed, to improve outcomes and decrease adverse drug effects.

Evaluation of the SAMe-TT2R2 score to predict the quality of anticoagulation control in patients with venous thromboembolism treated with vitamin K antagonists: Findings from the RIETE registry

BACKGROUND

The time in therapeutic range (TTR) of patients with venous thromboembolism (VTE) treated with vitamin K antagonists (VKA) is usually below recommended, leading to higher frequency of vascular events, bleeding and mortality. The SAMe-TT2R2 prediction score discriminates those patients with high or low probability of obtaining poor INR control and its use is recommended in patients with atrial fibrillation. Its usefulness has been evaluated in patients with VTE, with conflicting results.

METHOD

We included consecutive patients enrolled in Registro Informatizado Enfermedad TromboEmbolica (RIETE), a prospective multicenter VTE registry, treated with VKA for >90 days and a minimum of 3 INR determinations. We analyzed the relationship between the SAMe-TT₂R₂ score and TTR, determined by the Rosendaal method and by the percentage of INR determinations (after excluding the first month). A ROC curve was calculated considering a cut-off point of TTR ≥65% for good anticoagulation control.

RESULTS

3893 patients were included and classified in high (1411 patients) or low (2482 patients) probability of obtaining poor INR control according to the total score obtained (0-1 points versus 2 points, respectively). TTR, calculated by direct method and Rosendaal method, was 51.2 (±23.4) and 55.4 (±25.9) in the high probability group; and 54.4 (±23.0) and 58.2 (±25.6) in the low probability group, respectively (p < 0.001 for both comparisons). The outcomes were similar between groups. The predictive capacity of the SAMe-TT2R2 score showed an area under the ROC curve of 0.54 (CI 95% 0.52-0.56) and 0.53 (CI 95% 0.51-0.55).

CONCLUSIONS

In patients with VTE treated with VKA, the SAMe-TT2R2 score discriminated those patients with high probability of obtaining poor INR control, but with a low predictive capacity. Further studies are required to assess the usefulness of the score in clinical decision-making.

The anti-clot treatment scale (ACTS): validation of the translated Arabic version among patients undergoing warfarin therapy in Saudi Arabia

Background

Long-term anticoagulation therapy, particularly with warfarin, is usually associated with poor adherence and low patient satisfaction. However, previous studies have highlighted the possibility that individual perceptions of warfarin differ according to cultural practices. This study validated the psychometric properties of the translated Arabic version of the Anti-Clot Treatment Scale (ACTS) for patients on warfarin therapy in Saudi Arabia.

Methods

A cross-sectional multicenter study was conducted at the three main medical centers in Riyadh. Stratified sampling was employed to recruit Arabic-speaking patients who had been taking warfarin for a minimum of 3 months for any indication. The patients completed the specific ACTS along with the generic Treatment Satisfaction Questionnaire for Medication (TSQM 1.4) at two clinic visits. The psychometric performance of the ACTS was evaluated using well-established criteria: feasibility, reliability, and validity.

Results

One hundred thirty-six patients participated in the study (mean age: 50.68 ± 14.6 years; range: 19–97). Overall, the patients reported moderate Burdens and Benefits scores (44 ± 9.9 and 11.92 ± 2.4, respectively) compared to the reference range for each subscale (12–60 and 3–15, respectively); however, they reported lower Burdens scores than other populations. Consistent with the original ACTS validation study, the criteria for acceptability (data targeting, floor/ceiling effects, and skewness) were satisfied; in fact, the Arabic version exhibited better item- and scale-level distributions of data than versions in other languages. The ACTS subscales also demonstrated satisfactory test-retest reliability with significant intraclass correlation coefficients ((ICC ≥ 0.5); p < 0.001) and good internal consistency (all Cronbach’s alpha values exceeded 0.7). Exploratory factor analysis supported the 2-factor loading model. Interestingly, the Arabic version exhibited greater convergent validity with the TSQM subdomains (r = 0.61).

Conclusions

This study provides convincing evidence that the Arabic versions of both the ACTS Burdens and ACTS Benefits scales are equivalent to other versions in terms of psychometric performance, as measured using reliability and validity criteria. These properties support the great potential of the Arabic ACTS to accurately reflect patient satisfaction, identify aspects of treatment that need improvement in clinical practice, and compare treatment satisfaction across different anticoagulant therapies or cultures in research.

Anticoagulation control in different ethnic groups receiving vitamin K antagonist therapy for stroke prevention in atrial fibrillation

BACKGROUND

Efficacy and safety of vitamin K antagonists (VKAs) is optimised in atrial fibrillation (AF) patients when the International Normalised Ratio (INR) is 2.0-3.0. Anticoagulation control comparing different ethnic groups is limited, although epidemiological studies suggest poorer INR control in non-white cohorts.

METHODS

VKA control was assessed retrospectively by time-in-the-therapeutic range (TTR) (Rosendaal method) and percentage INR-in-range (PINRR) in 991 White, Afro-Caribbean and South-Asian AF patients [overall mean (SD) age 71.6 (9.4) years; 55% male; mean (SD) CHA₂DS₂-VASc score 3.4 (1.6)] over a median (IQR) follow-up of 5.2 (3.2-7.0) years.

RESULTS

Compared to Whites, mean (SD) TTR and PINRR were significantly lower in South-Asians [TTR 67.9% vs. 60.5%; PINRR 58.8% vs. 51.6%, respectively] and Afro-Caribbeans [TTR 67.9% vs. 61.3%; PINRR 58.8% vs. 53.1%, respectively], despite similar INR monitoring intensity. Logistic regression revealed non-white ethnicity [OR 2.62; 95% Confidence Interval [CI] (1.67-4.10) and OR 3.47 (1.44-8.34)] and anaemia [OR 1.65 (1.00-2.70) and OR 6.27 (1.89-20.94)] as independent predictors of both TTR and PINRR < 70%, respectively. At follow-up, 329 (33.2%) patients experienced ≥1 major adverse clinical event. Cardiovascular hospitalisation was significantly higher among South-Asians (32.3%) compared to the Whites and Afro-Caribbeans (21.3% vs 25.6% respectively).

CONCLUSIONS

Ethnic disparities in quality of anticoagulation control are evident, with South-Asians and Afro-Caribbeans having poorer control compared to Whites, despite similar intensity INR monitoring. Non-white ethnicity remained the strongest independent predictor of poor TTR and PINRR. Interventions to improve anticoagulation control need to be implemented, particularly targeting ethnic minority patients.

[Pharmacist-led anticoagulation monitoring can significantly improve the effectiveness and safety of warfarin for patients during hospitalization]

OBJECTIVE

To investigate the role of pharmacist-led anticoagulation monitoring service for warfarin anticoagulation therapy in patients during hospitalization.

METHODS

We retrospectively analyzed the data of 421 patients receiving warfarin anticoagulation therapy during hospitalization between April, 2016 and December, 2017. Of these patients, 316 received daily pharmacist-led anticoagulation monitoring service including checking the patients' International Normalized Ratio (INR) and other pertinent laboratory test results and reviewing medication changes and the patients' clinical status (monitoring group); the other 105 patients receiving warfarin anticoagulation therapy without pharmaceutical care served as the control group. The data including compliance rate of anticoagulant indicators, incidence and rate of prompt management of INR alert, thrombosis and bleeding events during hospitalization were analyzed among these patients.

RESULTS

Compared with the control patients, the patients in the monitoring group showed a significantly higher percentage time within target INR range [(73.20±9.46)% vs (46.32±17.11)%, P < 0.001] and a higher qualified rate of INR before discharge (98.42% vs 60.95%, P < 0.001) as well as a higher proper INR-monitoring frequency (97.15% vs 66.67%, P < 0.001). The patients in the monitoring group showed a significantly lower incidence of INR alert than the control patients (8.23% vs 20.00%, P < 0.001) with also a much higher rate of prompt management (96.15% vs 33.33%). The two groups had similar incidences of clinical events except that the control group reported a higher incidence of minor bleeding episodes (9.52% vs 2.53%, P=0.005).

CONCLUSIONS

Pharmacist-led anticoagulation monitoring service can significantly improve the effectiveness and safety of warfarin anticoagulation therapy for patients during hospitalization.

Cost of Healthcare Associated With Deep Vein Thrombosis in Patients Treated With Warfarin in Turkey: 2010-2013 Database Analysis of a Tertiary Care Center

OBJECTIVES

To evaluate the cost of healthcare with respect to the quality of anticoagulation in patients with deep vein thrombosis (DVT) treated with warfarin in daily practice via the database analysis of a tertiary care center in the period 2010 to 2013.

METHODS

Of 258 307 records in total, 42 582 unique patients with DVT and 32 012 patients with international normalized ratio (INR) measurements were included. Overall, 6720 unique patients with DVT diagnosis and one or more INR measurements were identified, and the records of 4377 out of 6720 unique patients were validated and included in the analysis data set. The cost analysis was based on direct medical costs from the payer's perspective. Cost items were related to healthcare resource utilization (inpatient and outpatient services) during the study period, which provided a basis for calculation of per-patient, outpatient, inpatient, and total direct medical costs.

RESULTS

Mean outpatient, inpatient, and total hospital admission costs were $578, $2195, and $2785, respectively, for patients with time in the therapeutic range of 70% or more, whereas the same costs were $571, $2163, and $3192, respectively, for patients with time in the therapeutic range of less than 70%.

CONCLUSIONS

Our findings for a retrospective cohort of patients with DVT undergoing warfarin therapy reveal that patients spent 70% or more, as opposed to less than 70%, of follow-up time within the therapeutic INR range and that outpatient care, as opposed to inpatient care, was associated with lower healthcare costs. Given the significant contribution that hospital stay makes to the cost burden of DVT, our findings also highlight the association between poor warfarin anticoagulant control and increased hospitalization costs.

Control of Anticoagulation Therapy in Patients with Atrial Fibrillation Treated with Warfarin: A Study from the Chinese Atrial Fibrillation Registry

Background

Several factors determine the efficacy of warfarin anticoagulation in patients with non-valvular atrial fibrillation (NVAF). This study aimed to use data from the Chinese Atrial Fibrillation Registry study to assess the control of anticoagulation therapy in Chinese patients with NVAF treated with warfarin.

Material/Methods

From the Chinese Atrial Fibrillation Registry study the anticoagulant use and dosing, the time in therapeutic range (TTR) of the international normalized ratio (INR), and standard deviation of the observed INR values (SD_INR), and their influencing factors were evaluated.

Results

The median INR and SD_INR were 2.04 (IQR 1.71–2.41) and 0.50 (IQR, 0.35–0.69), respectively. The median TTR was 51.7% (IQR, 30.6–70.1%) and only 25.1% had a TTR ≥70%. Age was ≥70 years (OR, 0.72; 95% CI, 0.55–0.94; P=0.015), bleeding history (OR 0.48; 95% CI, 0.23–0.89; P=0.029), the use of a single drug (OR, 0.62; 95% CI, 0.42–0.92; P=0.016), more than drug (OR, 0.60; 95% CI, 0.41–0.88; P=0.009), and lack of assessment of bleeding risk (OR, 0.72; 95% CI, 0.54–0.97; P=0.033) were associated with TTR <70% (INR 2.0–3.0). Coronary heart disease (CHD) and peripheral artery disease (PAD) (OR, 0.69; 95% CI, 0.52–0.90; P=0.007) and diabetes mellitus (OR, 0.79; 95% CI, 0.62–0.99; P=0.044) were associated with increased variability in INR (SD_INR ≥0.5).

Conclusions

In Chinese patients with NVAF, warfarin anticoagulation was associated with lower TTR and less stable anticoagulation than in current guidelines, and risk factors for reduced safety and efficacy were identified.

Quality of Anticoagulation With Warfarin at a Tertiary Hospital in Botswana

Warfarin treatment requires regular and proper monitoring to avoid overanticoagulation and at the same time to prevent thromboembolic complications. This study assessed the quality of warfarin anticoagulation at Princess Marina Hospital in Botswana. This cross-sectional study consecutively enrolled patients who were on warfarin for at least 3 months in the outpatient medical clinic. The level of anticoagulation was determined by the time in therapeutic range (TTR) using the Rosendaal method that calculates the percentage of days when the international normalized ratio is in the therapeutic range (2.0-3.0). Poor anticoagulation control was defined as an estimated TTR <65%. We performed univariate and multivariate logistic regression to assess predictors of poor anticoagulation control. Of total, 410 (68.8% women) patients whose median age was 46 (interquartile range [IQR], 35-58) years were enrolled. Indications for warfarin included mechanical heart valves, 185 (45.1%); deep vein thrombosis, 114 (26.8%); and atrial fibrillation, 68 (17.8%). Of the 2004 tests (an average of 4.9 tests per patient) assessed, only 20% of the tests were within the therapeutic range. The median TTR was 30.8% (IQR, 15.2-52.7). Most (85.1%) patients had poor anticoagulation control. Cigarette smoking and pulmonary hypertension perfectly predicted poor anticoagulation. Hypertension was a predictor of poor anticoagulation control (adjusted odds ratio = 2.24; 95% confidence interval: 1.02-4.94). The quality of anticoagulant therapy with warfarin in Botswana patients is poor. The evidence calls for efforts to improve the level of anticoagulation control among patients on warfarin in Botswana.

Lower tacrolimus exposure and time in therapeutic range increase the risk of de novo donor-specific antibodies in the first year of kidney transplantation

De novo donor-specific antibodies (dnDSAs) have been associated with reduced graft survival. Tacrolimus (TAC)-based regimens are the most common among immunosuppressive approaches used in in clinical practice today, yet an optimal therapeutic dose to prevent dnDSAs has not been established. We evaluated mean TAC C0 (tacrolimus trough concentration) and TAC time in therapeutic range for the risk of dnDSAs in a cohort of 538 patients in the first year after kidney transplantation. A mean TAC C0  < 8 ng/mL was associated with dnDSAs by 6 months (odds ratio [OR] 2.51, 95% confidence interval [CI] 1.32-4.79, P = .005) and by 12 months (OR 2.32, 95% CI 1.30-4.15, P = .004), and there was a graded increase in risk with lower mean TAC C0 . TAC time in the therapeutic range of <60% was associated with dnDSAs (OR 2.05, 95% CI 1.28-3.30, P = .003) and acute rejection (hazard ratio [HR] 4.18, 95% CI 2.31-7.58, P < .001) by 12 months and death-censored graft loss by 5 years (HR 3.12, 95% CI 1.53-6.37, P = .002). TAC minimization may come at a cost of higher rates of dnDSAs, and TAC time in therapeutic range may be a valuable strategy to stratify patients at increased risk of adverse outcomes.

Development of Quality Indicators to Assess Oral Anticoagulant Management in Community Pharmacies for Patients with Atrial Fibrillation

BACKGROUND

Few studies have evaluated the quality of oral anticoagulant management by community pharmacists. There is no complete set of quality indicators available for this purpose.

OBJECTIVE

To develop a set of specific quality indicators to assess oral anticoagulant management by community pharmacists for patients with atrial fibrillation (AF).

METHODS

Quality indicators were developed in 3 phases. In phase 1, potential quality indicators were generated based on clinical guidelines and a literature review. In phase 2, a modified RAND appropriateness method involving 2 rounds was implemented with 9 experts, who judged the appropriateness of quality indicators generated in phase 1 based on the extent to which they were accurate, based on evidence, relevant, representative of best practices, and measurable in community pharmacies. Phase 3 consisted of a feasibility assessment in 5 community pharmacies on 2 patients each.

RESULTS

The final set included 38 quality indicators grouped into 6 categories: documentation (n = 29), risk assessment (n = 3), clinical control (n = 1), clinical follow-up (n = 15), choice of therapy (n = 11), and interaction management (n = 8). The quality indicators referred to process of care (n = 34), clinical outcomes (n = 2), or structure of care (n = 2). There were 24 quality indicators related to vitamin K antagonists (VKAs), and 17 were related to direct oral anticoagulants (DOACs). To assess quality indicators, a questionnaire was developed for completion by community pharmacists for each patient, which included 17 questions about VKA patients and 12 questions about DOAC patients.

CONCLUSIONS

A first set of quality indicators is now available to assess the quality of oral anticoagulant management by community pharmacists for patients with AF.

DISCLOSURES

This research was supported by the Réseau Québécois de recherche sur le médicament (RQRM); the Blueprint for Pharmacy in collaboration with Pfizer Canada; and the Cercle du Doyen of the Faculty of Pharmacy, University of Montreal. The study sponsors were not involved in the study design, data collection, data interpretation, the writing of the article, or the decision to submit the report for publication. Chartrand received a scholarship from the Fonds de Recherche du Québec en Santé (FRQ-S), the Réseau Québécois de recherche sur l'usage des médicaments with Pfizer, and the Faculty of Pharmacy, University of Montreal. Guénette holds a Junior-1 Clinician Researcher Award from the FRQ-S in partnership with the Société québécoise d'hypertension artérielle. Williamson holds a Junior-1 Career Award from the FRQ-S. Côté reported being a medical speaker for Bayer, Boehringer Ingelheim Canada, and Pfizer Canada. The other authors reported no conflicts of interest. Study concept and design were contributed by Lalonde, Chartrand, and Martin. Chartrand, Martin, and Lalonde collected the data, along with Brouillette, Côté, Huot, Landry, Martineau, Perreault, Williamson, and White-Guay. Data interpretation was performed by Chartrand, Gagnon, and Lalonde, along with Guénette and Martin. The manuscript was primarily written by Chartrand, along with Guénette and Lalonde, and revised by Chartrand, Guénette, and Lalonde, along with the other authors. A portion of this study's results was presented at the 4th RQRM Annual Meeting on September 22-23, 2014, in Orford, Quebec, Canada, in the form of an abstract, which was published in the Journal of Population Therapeutics and Clinical Pharmacology, 2014;21(2):e312.

Quality of Anticoagulation With Warfarin at a Tertiary Hospital in Botswana

Warfarin treatment requires regular and proper monitoring to avoid overanticoagulation and at the same time to prevent thromboembolic complications. This study assessed the quality of warfarin anticoagulation at Princess Marina Hospital in Botswana. This cross-sectional study consecutively enrolled patients who were on warfarin for at least 3 months in the outpatient medical clinic. The level of anticoagulation was determined by the time in therapeutic range (TTR) using the Rosendaal method that calculates the percentage of days when the international normalized ratio is in the therapeutic range (2.0-3.0). Poor anticoagulation control was defined as an estimated TTR <65%. We performed univariate and multivariate logistic regression to assess predictors of poor anticoagulation control. Of total, 410 (68.8% women) patients whose median age was 46 (interquartile range [IQR], 35-58) years were enrolled. Indications for warfarin included mechanical heart valves, 185 (45.1%); deep vein thrombosis, 114 (26.8%); and atrial fibrillation, 68 (17.8%). Of the 2004 tests (an average of 4.9 tests per patient) assessed, only 20% of the tests were within the therapeutic range. The median TTR was 30.8% (IQR, 15.2-52.7). Most (85.1%) patients had poor anticoagulation control. Cigarette smoking and pulmonary hypertension perfectly predicted poor anticoagulation. Hypertension was a predictor of poor anticoagulation control (adjusted odds ratio = 2.24; 95% confidence interval: 1.02-4.94). The quality of anticoagulant therapy with warfarin in Botswana patients is poor. The evidence calls for efforts to improve the level of anticoagulation control among patients on warfarin in Botswana.

Differences among western European countries in anticoagulation management of atrial fibrillation

Due to improved implementation of guidelines, new scoring approaches to improve risk categorisation, and introduction of novel oral anticoagulants, medical management of patients with atrial fibrillation (AF) is continuously improving. The PREFER in AF registry enrolled 7,243 consecutive patients with ECG-confirmed AF in seven European countries in 2012–2013 (mean age: 71.5 ± 10.7 years; 60.1% males; mean CHA2DS 2 -VASc score: 3.4). While patient characteristics were generally homogeneous across countries, anticoagulation management showed important differences: the proportion of patients taking vitamin K antagonists (VKAs) varied between 86.0% (in France) and 71.4% (in Italy). Warfarin was used predominantly in the UK and Italy (74.9% and 62.0%, respectively), phenprocoumon in Germany (74.1%), acenocoumarol in Spain (67.3%), and fluindione in France (61.8 %). The major sites for international normalised ratio (INR) measurements were biology laboratories in France anticoagulation clinics in Italy, Spain, and the UK, and physicians’ offices or self-measurement in Germany. Temporary VKA discontinuation and bridging with other anticoagulants was frequent (at least once in the previous 12 months for 22.9% of the patients, on average; ranging from 29.7% in Germany to 14.9% in the UK). Time in therapeutic range (TTR), defined as at least two of the last three available INR values between 2.0–3.0 prior to enrolment, ranged from 70.3% in Spain to 81.4% in Germany. TTR was constantly overestimated by physicians. While the type and half-lives of VKA as well as the mode of INR surveillance differed, overall quality of anticoagulation management by TTR was relatively homogenous in AF patients across countries.

[Prevalence of oral anticoagulation and quality of its management in primary healthcare: A study by the Health Sentinel Network of the Region of Valencia (Spain)]

OBJECTIVE

To estimate the prevalence of patients with oral anticoagulant therapy (OAT) in the Region of Valencia and to evaluate the quality of management of OAT with vitaminK antagonists (VKA) carried out in primary healthcare.

DESIGN

Observational cross-sectional study conducted through the Health Sentinel Network of the Region of Valencia, which includes a survey and the retrospective analysis of OAT monitoring.

SETTING

Primary healthcare, Region of Valencia, Spain.

SUBJECTS

All patients aged 18years or older on OAT who consulted during the year 2014. The population covered by the 59 doctors of the Health Sentinel Network constitutes 2.2% of the adult population of the Region of Valencia, and it is representative of it.

KEY MEASUREMENTS

Demographic, socioeconomic and health data as well as information concerning OAT. Quality of OAT management with VKA was assessed by means of the percentage of time in therapeutic range (TTR), computed using the Rosendaal method.

RESULTS

A total of 1,144 patients were recorded (mean age 74.5±11 years; 49.7% women). Prevalence of OAT in the Region of Valencia is 1.3 cases per 100 population. The characteristic profile of these patients is an old person, with several comorbidities and a low level of education, who lives accompanied. Atrial fibrillation is the most common indication. 82.8% of patients on OAT with VKA were monitored in primary healthcare. The average TTR was 65.0%, and 53.9% of patients had a TTR ≥65%. Among inadequately controlled patients, 74.4% were perceived as well-controlled by their primary care doctor.

CONCLUSIONS

Prevalence of OAT is high, and it is expected to increase. The degree of control achieved meets the generally accepted quality standard (mean TTR ≥65%), and it is comparable to that observed in other national and international studies. However, there is wide scope for improvement. It is crucial to optimize the management of this therapy in the most effective and cost-effective way. Among other measures, access of physicians to their patients' clinical information should be improved.

Derivation and validation of a novel bleeding risk score for elderly patients with venous thromboembolism on extended anticoagulation

Existing clinical scores do not perform well in predicting bleeding in elderly patients with acute venous thromboembolism (VTE). We sought to derive an easy-to-use clinical score to help physicians identify elderly patients with VTE who are at high-risk of bleeding during extended anticoagulation (>3 months). Our derivation sample included 743 patients aged ≥65 years with VTE who were enrolled in a prospective multicenter cohort study. All patients received extended anticoagulation with vitamin K antagonists. We derived our score using competing risk regression, with the time to a first major bleeding up to 36 months of extended anticoagulation as the outcome, and 17 candidate variables as predictors. We used bootstrapping methods for internal validation. Sixty-six (9 %) patients suffered major bleeding. The clinical score is based on seven clinical factors (previous bleeding, active cancer, low physical activity, anemia, thrombocytopenia, antiplatelet drugs/NSAIDs, and poor INR control). Overall, 48 % of patients were classified as low-risk, 37 % as moderate-risk, and 15 % as high-risk of bleeding. The rate of major bleeding was 1.4 events in low-risk, 5.0 events in moderate-risk, and 12.2 events per 100 patient-years in high-risk patients. The c-statistic was 0.78 at 3 months and 0.71 at 36 months of extended anticoagulation. Model calibration was excellent (p=0.93). Internal validation showed similar results. This simple clinical score accurately identified elderly patients with VTE who are at high risk of major bleeding and who may not benefit from extended anticoagulation. Further validation of the score is important before its implementation into practice. The study is registered to https://clinicaltrials.gov as NCT00973596.

Efficacy of protocol-based pharmacotherapy management on anticoagulation with warfarin for patients with cardiovascular surgery

WHAT IS KNOWN AND OBJECTIVE

Anticoagulation therapy with warfarin requires periodic monitoring of prothrombin time-international normalized ratio (PT-INR) and adequate dose adjustments based on the data to minimize the risk of bleeding and thromboembolic events. In our hospital, we have developed protocol-based pharmaceutical care, which we called protocol-based pharmacotherapy management (PBPM), for warfarin therapy. The protocol requires pharmacists to manage timing of blood sampling for measuring PT-INR and warfarin dosage determination based on an algorithm. This study evaluated the efficacy of PBPM in warfarin therapy by comparing to conventional pharmaceutical care.

METHODS

From October 2013 to June 2015, a total of 134 hospitalized patients who underwent cardiovascular surgeries received post-operative warfarin therapy. The early series of patients received warfarin therapy as the conventional care (control group, n=77), whereas the latter received warfarin therapy based on the PBPM (PBPM group, n=68). These patients formed the cohort of the present study and were retrospectively analysed.

RESULTS

The indications for warfarin included aortic valve replacement (n=56), mitral valve replacement (n=4), mitral valve plasty (n=22) and atrial fibrillation (n=29). There were no differences in patients' characteristics between both groups. The percentage time in therapeutic range in the first 10 days was significantly higher in the PBPM group (47.1%) than that in the control group (34.4%, P<.005). The average time to reach the steady state was significantly (P<.005) shorter in the PBPM group compared to the control group (7.3 vs 8.6 days).

WHAT IS NEW AND CONCLUSION

Warfarin therapy based on our novel PBPM was clinically safe and resulted in significantly better anticoagulation control compared to conventional care.

The patients' perspective of international normalized ratio self-testing, remote communication of test results and confidence to move to self-management

AIMS AND OBJECTIVES

To elicit the perceptions of patients, who self-tested their international normalized ratio and communicated their results via a text or phone messaging system, to determine their satisfaction with the education and support that they received and to establish their confidence to move to self-management.

BACKGROUND

Self-testing of international normalized ratio has been shown to be reliable and is fast becoming common practice. As innovations are introduced to point of care testing, more research is needed to elicit patients' perceptions of the self-testing process.

DESIGN

This three site study used a cross-sectional prospective descriptive survey.

METHODS

Three hundred and thirty patients who were prescribed warfarin and using international normalized ratio self-testing were invited to take part in the study. The anonymous survey examined patient profile, patients' usage, issues, perceptions, confidence and satisfaction with using the self-testing system and their preparedness for self-management of warfarin dosage.

RESULTS

The response rate was 57% (n = 178). Patients' confidence in self-testing was high (90%). Patients expressed a high level of satisfaction with the support received, but expressed the need for more information on support groups, side effects of warfarin, dietary information and how to dispose of needles. When asked if they felt confident to adjust their own warfarin levels 73% agreed. Chi-squared tests for independence revealed that none of the patient profile factors examined influenced this confidence. The patients cited the greatest advantages of the service were reduced burden, more autonomy, convenience and ease of use. The main disadvantages cited were cost and communication issues.

CONCLUSION

Patients were satisfied with self-testing. The majority felt they were ready to move to self-management.

RELEVANCE TO CLINICAL PRACTICE

The introduction of innovations to remote point of care testing, such as warfarin self-testing, needs to have support at least equal to that provided in a hospital setting.

Time in the Therapeutic Range (TTR): An Overly Simplified Conundrum

Anticoagulation with warfarin has been used for over 60 years; however, its administration is fraught with difficulty since many factors can affect warfarin dosing. The concept of time in therapeutic range (TTR) has become a popular way to report warfarin management and compare anticoagulation management across clinical trials. However, TTR is a much more complex concept than most clinicians and trialists recognize. This manuscript attempts to discuss some of the important factors underlying this complexity and presents a suggestion to improve reports on TTR.

Time to Revisit the Time in the Therapeutic Range

In recent clinical trials, the \"quality\" of warfarin management has been characterized by the time in therapeutic range (TTR) -- with the therapeutic range being an INR between 2.0 and 3.0. In many reviews of recent clinical trials, differences in the TTR have been used comparatively to critique and contrast the trials. However, TTR is a more complex measurement than is commonly appreciated, and many factors that underlie the TTR calculation, which can differ from trial to trial, have not been adequately addressed. This manuscript attempts to explain these issues so as to help the reader understand the factors that contribute to TTR and to understand the limitations of TTR so as to better understand anticoagulation trial results. It also addresses the issue of INRs below or above the therapeutic range, that can differ among trials, that are not provided simply by presenting a TTR value, but that can in a substantial way affect the bleeding risk and embolism-prevention likelihood of anticoagulation in a trial.

Venous Thromboembolism Requiring Extended Anticoagulation Among HIV-Infected Patients in a Rural, Resource-Constrained Setting in Western Kenya

BACKGROUND

HIV-infected patients are at an increased risk of developing venous thromboembolism (VTE), and minimal data are available to describe the need for extended treatment.

OBJECTIVE

To evaluate the frequency of and determine predictive risk factors for extended anticoagulation of VTE in HIV-infected patients in rural, western Kenya.

METHODS

A retrospective chart review was conducted at the Anticoagulation Monitoring Service affiliated with Moi Teaching and Referral Hospital and the Academic Model Providing Access to Healthcare. Data were collected on patients who were HIV-infected and receiving anticoagulation for lower-limb deep vein thrombosis. The need for extended anticoagulation, defined as receiving ≥7 months of warfarin therapy, was established based on patient symptoms or Doppler ultrasound-confirmed diagnosis. Evaluation of the secondary outcomes utilized a univariate analysis to identify risk factors associated with extended anticoagulation.

RESULTS

A total of 71 patients were included in the analysis; 27 patients (38%) required extended anticoagulation. The univariate analysis showed a statistically significant association between the need for extended anticoagulation and achieving a therapeutic international normalized ratio within 21 days in both the unadjusted and adjusted analysis. Patients with a history of opportunistic infections required an extended duration of anticoagulation in the adjusted analysis: odds ratio = 3.42; 95% CI = 1.04-11.32; P = 0.04.

CONCLUSIONS

This study shows that there may be a need for increased duration of anticoagulation in HIV-infected patients, with a need to address the issue of long-term management. Guideline recommendations are needed to address the complexity of treatment issues in this population.

Improvement of time in therapeutic range with warfarin by pharmaceutical intervention

Background Anticoagulation therapy with warfarin is highly effective for prevention and treatment of thromboembolic disorders. Nevertheless, its management is challenging especially in developing countries, where the medical access is difficult and patient education is poor. Objective To determine the effect of pharmaceutical intervention (PI) on the time in therapeutic range (TTR) of a group of anticoagulated patients from our referral center. Method A group of consecutive outpatients previously treated by usual medical care underwent PI. The intervention consisted in the identification and avoidance of food and drug interactions, the confection of medication schedule charts and education to patients regarding side effects and drug monitoring. Mean TTR before and after PI was compared through the Wilcoxon test for repeated measures. Regression analyses were performed to assess the relationship between a TTR level under 65% and potential explanatory variables. Results Mean TTR before PI was 37.4 ± 23.5% and after PI it raised to 67.0 ± 24.9%. Mean change in TTR was +29.5% (95% CI 14.5-44.6; p < 0.001). Before PI only 4 patients had TTR values above 65%, in contrast to 18 patients after PI. Conclusion Our findings support the efficacy of PI to improve TTR values in patients treated with warfarin.

Influence of VKORC1 and CYP2C9 Polymorphisms on Daily Acenocoumarol Dose Requirement in South Indian Patients With Mechanical Heart Valves

Background and Aim:

Chronic rheumatic heart disease (RHD) patients who undergo valve replacement with mechanical valves require lifelong anticoagulation. Acenocoumarol, a vitamin K antagonist has a narrow therapeutic range and wide inter-individual variability. Our aim was to investigate the influence of polymorphisms of VKORC1 and CYP2C9 genes on the mean daily dose requirement of acenocoumarol.

Methods:

205 chronic RHD patients, with mechanical heart valves and on acenocoumarol therapy, were recruited. Genotyping for VKORC1 (−1639G>A and 1173C>T) and CYP2C9 (*2 & *3 alleles) polymorphisms was done by PCR-RFLP. There was complete linkage disequilibrium between VKORC1 polymorphisms (r2 = 0.98, D′ = 1.0, LOD = 74.02). VKORC1 genotype distribution for GG/CC, GA/CT, and AA/TT were 57.6%, 36.1%, and 6.3%, respectively. CYP2C9 genotype distribution for *1/*1, *1/*3, *1/*2, *2/*2, and *2/*3 were 78.5%, 14.1%, 6.3%, 0.5%, and 0.5%, respectively. Patients with a wild type of both VKORC1 (−1639GG and 1173CC) and CYP2C9 gene variants required higher acenocoumarol dose compared to those with mutant genotype ( P = 0.023 and P = 0.008 respectively). On combined genotype analysis, patients having a combination of wild type of VKORC1 with wild type of CYP2C9 (44.4%) required higher daily dose compared to patients bearing heterozygous VKORC1 (−1639GA & 1173CT) with wild type of CYP2C9 (30.2%, P = 0.008).

Conclusion:

Presence of a mutant allele of VKORC1 (−1639A & 1173T) and CYP2C9 genes increased the odds of requiring a lower mean dosage of acenocoumarol. Studying the combination of genotypes in RHD patients could predict acenocoumarol dose requirement more accurately.

Impact of Point-of-Care Implementation in Pharmacist-Run Anticoagulation Clinics Within a Community-Owned Health System: A Two-Year Retrospective Analysis

BACKGROUND

Point-of-care (POC) testing devices allow laboratory monitoring to be performed in various settings and accessed immediately.

OBJECTIVE

To evaluate the outcomes of monitoring anticoagulation patients in pharmacistmanaged, multicenter clinics utilizing i-STAT POC machines.

METHODS

This study was a retrospective, multicenter chart review of 150 patients before and after implementation of the POC intervention for anticoagulation monitoring. Data collected included international normalized ratio (INR) results, indication for warfarin, minor and major bleeds, thromboembolic events, emergency room (ER) visits, and hospitalizations before and after i-STAT POC implementation.

RESULTS

The time in therapeutic INR range (TTR) was significantly higher after i-STAT POC implementation than before implementation (60.4% ± 21.2% and 52.5% ± 21.5%, respectively; P = .0001). There were no reports of major bleeding during the study period. Twenty-three minor bleeds were reported after i-STAT POC implementation compared to 19 events before implementation (P < .0001). One thromboembolic event was reported after i-STAT POC implementation. There was a significant difference in the number of hospitalizations before i-STAT POC implementation as opposed to after implementation (2 and 0, respectively; P < .0001). There was also a significant increase in ER visits after i-STAT POC implementation (P < .0001).

CONCLUSION

The results of the study indicate improvement in TTR in pharmacist-managed anticoagulation clinics by 7.8%. Although the use of the i-STAT POC machine detected an increase in minor bleeds, thromboembolic events, and ER visits, there was a decrease in hospitalization. The outcomes of this multicenter study indicate that implementation on this scale provides improvement in regard to safety and cost.

Comorbidities against quality control of VKA therapy in non-valvular atrial fibrillation: a French national cross-sectional study

Background

Given the prevalence of non-valvular atrial fibrillation in the geriatric population, thromboembolic prevention by means of vitamin K antagonists (VKA) is one of the most frequent daily concerns of practitioners. The effectiveness and safety of treatment with VKA correlates directly with maximizing the time in therapeutic range, with an International Normalized Ratio (INR) of 2.0-3.0. The older population concentrates many of factors known to influence INR rate, particularly concomitant medications and concurrent medical conditions, also defined as comorbidities.

Objective

Determine whether a high burden on comorbidities, defined by a Charlson Comorbidity Index (CCI) of 3 or greater, is associated a lower quality of INR control.

Study-Design

Cross-sectional study.

Settings

French geriatric care units nationwide.

Participants

2164 patients aged 80 and over and treated with vitamin K antagonists.

Measurements

Comorbidities were assessed using the Charlson Comorbidity Index (CCI). The recorded data included age, sex, falls, kidney failure, hemorrhagic event, VKA treatment duration, and the number and type of concomitant medications. Quality of INR control, defined as time in therapeutic range (TTR), was assessed using the Rosendaal method.

Results

487 patients were identified the low-quality control of INR group. On multivariate logistic regression analysis, low-quality control of INR was independently associated with a CCI ≥3 (OR = 1.487; 95% CI [1.15; 1.91]). The other variables associated with low-quality control of INR were: hemorrhagic event (OR = 3.151; 95% CI [1.64; 6.07]), hospitalization (OR = 1.614, 95% CI [1.21; 2.14]).

Conclusion

An elevated CCI score (≥3) was associated with low-quality control of INR in elderly patients treated with VKA. Further research is needed to corroborate this finding.

[Computer aided dosage management of phenprocoumon anticoagulation therapy. Clinical validation]

A recently developed multiparameter computer-aided expert system (TheMa) for guiding anticoagulation with phenprocoumon (PPC) was validated by a prospective investigation in 22 patients. The PPC-INR-response curve resulting from physician guided dosage was compared to INR values calculated by "twin calculation" from TheMa recommended dosage. Additionally, TheMa was used to predict the optimal time to perform surgery or invasive procedures after interruption of anticogulation therapy.

RESULTS

Comparison of physician and TheMa guided anticoagulation showed almost identical accuracy by three quantitative measures: Polygon integration method (area around INR target) 616.17 vs. 607.86, INR hits in the target range 166 vs. 161, and TTR (time in therapeutic range) 63.91 vs. 62.40 %. After discontinuation of anticoagulation therapy, calculating the INR phase-out curve with TheMa INR prognosis of 1.8 was possible with a standard deviation of 0.50 ± 0.59 days.

CONCLUSION

Guiding anticoagulation with TheMa was as accurate as Physician guided therapy. After interruption of anticoagulant therapy, TheMa may be used for calculating the optimal time performing operations or initiating bridging therapy.

Improvement of anticoagulant treatment using a dynamic decision support algorithm: a Danish Cohort study

INTRODUCTION

Warfarin is the most widely prescribed vitamin K antagonist and in the United States and Europe more than 10 million people are currently in long-term oral anticoagulant treatment. This study aims to retrospectively validate a dynamic statistical model providing dosage suggestions to patients in warfarin treatment.

MATERIALS AND METHODS

The model was validated on a cohort of 553 patients with a mean TTR of 83%. Patients in the cohort were self-monitoring and managed by a highly specialised anticoagulation clinic. The predictive model essentially consists of three parts handling INR history, warfarin dosage and biological noise, which allows for prediction of future INR values and optimal warfarin dose to stay on INR target. Further, the model is based on parameters initially being set to population values and gradually individualised during monitoring of patients.

PRIMARY OUTCOME

Time in therapeutic range was used as surrogate quality measure of the treatment, and model-suggested dosage of warfarin was used to assess the accuracy of the model performance.

RESULTS

The accuracy of the model predictions measured as median absolute error was 0.53 mg/day (interquartile range from 0.25 to 1.0). The model performance was evaluated by the difference between observed and predicted warfarin intake in the preceding week of an INR measurement. In more than 70% of the cases where INR measurements were outside the therapeutic range, the model suggested a more reasonable dose than the observed intake.

CONCLUSION

Applying the proposed dosing algorithm can potentially further increase the time in INR target range beyond 83%.

Performance outcomes of a pharmacist-managed anticoagulation clinic in the rural, resource-constrained setting of Eldoret, Kenya

BACKGROUND

It is recommended that warfarin therapy should be managed through an anticoagulation monitoring service to minimize the risk of bleeding and subsequent thromboembolic events. There are few studies in Sub-Saharan Africa that describe warfarin management in spite of the high incidence of venous thromboembolism (VTE) and rheumatic heart disease.

OBJECTIVE

To examine the feasibility of the Moi Teaching and Referral Hospital anticoagulation monitoring service and compare its performance with clinics in resource-rich settings.

METHODS

A retrospective chart review compared the percentage time in the therapeutic range (TTR) and rates of bleeding and thromboembolic events to published performance targets using the inference on proportions test. Wilcoxon's rank sum analyses were used to establish predictors of TTR.

RESULTS

For the 178 patients enrolled, the mean TTR was 64.6% whereas the rates of major bleeds and thromboembolic events per year were 1.25% and 5%, respectively. In the primary analysis, no statistically significant differences were found between the results of TTR, major bleeds and thromboembolic events for the clinic and published performance rates. In the secondary analysis, having an artificial heart valve and a duration of follow-up of > 120 days were positively associated with a higher TTR (P < 0.05) whereas venous thromboembolism, history of tuberculosis, HIV and a duration of follow-up of < 120 days were associated with having a lower TTR (P < 0.05).

CONCLUSIONS

The performance of the MTRH anticoagulation clinic is non-inferior to published metrics on the performance of clinics in resource-rich settings.

Quality of management of oral anticoagulation as assessed by time in therapeutic INR range in elderly and younger patients with low mean years of formal education: a prospective cohort study

BACKGROUND

despite the overwhelming evidence of its effectiveness, oral anticoagulation continues to be underused in the elderly, presumably due to physicians' misconceptions when estimating bleeding risk and ability to comply with treatment.

OBJECTIVE

to investigate the quality of anticoagulation control among deprived elderly and younger patients.

DESIGN

prospective observational study.

SETTING

a public anticoagulation clinic in a developing country.

SUBJECTS

all adult patients on intended long-term (>90 days) oral anticoagulation. We studied 171 patients (79 elderly and 92 non-elderly) with a mean follow-up of 273 ± 84.9 days.

METHODS

the main outcome measure was the quality of anticoagulation management as measured by the time in therapeutic (TTR) international normalised ratio (INR) range. Elderly patients (≥60 years) were compared with younger patients with respect to the educational level and co-morbidities.

RESULTS

the mean number of years of formal education was 4.37 ± 3.2 years. The mean TTR was 62.50 ± 17.9% in non-elderly and 62.10 ± 16.6% in elderly (P = 0.862) subjects, despite the higher prevalence of co-morbidities in the latter group: heart failure (46.3 versus 28.6%, P = 0.042), diabetes mellitus (22.8 versus 8.7%, P = 0.011), renal failure (estimated glomerular filtration rate <50 ml/min: 38.0 versus 7.1%, P < 0.001) and polypharmacy (84.8 versus 58.7%, P < 0.001). Fifty elderly and 84 non-elderly subjects require little or no assistance in taking medications. Among them, the elderly had lower educational levels (3.42 ± 2.5 versus 5.55 ± 3.4 years of formal education, P < 0.001) and higher rates of cognitive impairment (34.0 versus 13.1%, P = 0.004), but a similar mean TTR (62.46 ± 16.1 versus 63.02 ± 17.8%, P = 0.856). The oldest (≥75 years) patients did as well as those aged ≤50 years (mean TTR: 62.54 ± 16.0 versus 62.23 ± 16.4%, respectively, P = 0.98).

CONCLUSIONS

good-quality management of oral anticoagulation is achievable in deprived populations attending an anticoagulation clinic. Elderly patients may experience similar quality of anticoagulation despite having higher levels of co-morbidities and polypharmacy. These results add evidence to the safety of such therapeutic interventions in the elderly.