Trends in oral anticoagulant use in Qatar: a 5-year experience

Evaluation of warfarin management in primary health care centers in Qatar: A retrospective cross-sectional analysis of the national dataset

BACKGROUND

Warfarin management is associated with severe complications, highlighting the critical need to evaluate the quality of its administration.

OBJECTIVES

To evaluate the quality of warfarin management for patients managed in primary healthcare centers by measuring the percentage of Time in Therapeutic Range (TTR) and the proportion of extreme out-of-range international normalized ratio (INR) values.

METHODS

This is a cross-sectional study. Data was extracted from a national dataset retrieved from the largest primary healthcare provider in Qatar. TTR was calculated using the traditional method. Inferential and descriptive analyses were performed as appropriate.

RESULTS

Four hundred ninety-four patients met the inclusion criteria. The mean (SD) TTR was 45.3 % (17.5). This was significantly lower than the recommended cutoff value (P<0.001). Extreme out-of-range INR accounted for 24.7 % of total INR readings.

CONCLUSIONS

The management of patients taking warfarin in Qatar is inadequate. More effective strategies are warranted to ensure safe and effective therapy.

Trends in prescribing and outcomes in obese versus non-obese patients receiving rivaroxaban therapy: an observational study using real-world data

PURPOSE

To investigate real-world prescribing trends and clinical outcomes based on body mass index (BMI) categorization in patients who received rivaroxaban therapy.

METHODS

This was a retrospective cohort study involving all patients who received rivaroxaban therapy across all Hamad Medical Corporation (HMC) hospitals from 2015 to 2020.

RESULTS

The number of patients initiated on rivaroxaban therapy significantly increased from 152 (3.3%) in 2015 to 1342 (28.9%) in 2020 (p <0.001). Within BMI categories, a similar increasing trend was observed in underweight, normal, and overweight patients, while from 2018 to 2020, there was a decreasing trend in rivaroxaban prescribing in all obese classes. The prevalence rate of all-cause mortality differed significantly between the BMI groups, with the highest mortality being among morbidly obese patients (BMI ≥ 40 kg/m2) (p< 0.001). On the other hand, no significant differences were found between the BMI groups in terms of bleeding, pulmonary embolism, deep vein thrombosis and stroke incidences. Multivariate logistic regression analyses showed that the likelihood of all-cause mortality was significantly higher in overweight and all categories of obese patients compared to underweight patients: overweight (OR: 5.3, 95% CI: 2.3-11.9, p< 0.001); obese class 1 (OR: 5.4, 95% CI: 2.3 - 12.2, p< 0.001); obese class 2 (OR: 6.5, 95% CI: 2.7 - 15.6, p< 0.001); and obese class 3 (OR: 3.7, 95% CI: 1.6 - 8.7, p = 0.003).

CONCLUSIONS

Rivaroxaban prescribing has significantly increased over the years across general population, with a noticeable decline in obese population during the last few years (from 2018 onwards). Furthermore, an appreciable association was evident between all-cause mortality and BMI of these patients.

Evolving Trends in Consumption of Direct Oral Anticoagulants in 65 Countries/Regions from 2008 to 2019

BACKGROUND

Direct oral anticoagulants (DOACs) have been increasingly utilised over warfarin. However, little is known about the relative consumption trends and costs of each DOAC at the global level.

METHODS

An ecological study using pharmaceutical sales data from IQVIA-MIDAS database was used to estimate consumption and cost of individual DOACs in 65 countries from 2008 to 2019. Consumption was estimated from the volume of DOACs sold, expressed as defined-daily-dose/1000-inhabitants/day (DDDTID). Compound and absolute annual growth rates were reported to quantify consumption changes over time. Costs were estimated as manufacturer price per day-of-therapy.

RESULTS

Global consumption of dabigatran, rivaroxaban, apixaban and edoxaban were 0.31, 1.05, 1.08 and 0.78 DDDTID, respectively, in Q2-2019, compared to 0.23, 0.54, 0.21 and 0.03 in Q2-2015, with highest consumption in Western Europe, Northern Europe and Oceania (18.2, 14.07, 13.14 DDDTID). In most countries (46/65, 70%), rivaroxaban contributed to most DOAC consumption (35%-100%), whereas dabigatran accounted for less than one-third. Edoxaban accounted for < 20% of the total in Northern America and Europe but contributed significant proportions in Japan (28.58%) and South Korea (31.37%). Longer median time-to-adoption from FDA approval for apixaban and edoxaban was observed. Costs of all DOACs were ~2-4 times higher in the USA, Puerto Rico and Thailand than in other countries.

CONCLUSIONS

Regional differences exist in consumption pattern and trends of individual DOACs over the past decade. Consumption of rivaroxaban and apixaban overtook dabigatran in most countries, whereas use of edoxaban remains limited except in East Asian countries. The USA pays higher prices for DOACs than other countries.

Evidence-based Management of Major Bleeding in Patients Receiving Direct Oral Anticoagulants: An Updated Narrative Review on the Role of Specific Reversal Agents

The indications of direct oral anticoagulants (DOACs) have expanded over the past 15 years. DOACs are effective and safe oral anticoagulants associated with lower bleeding risks and mortality than vitamin K antagonists. However, DOAC users are prone to a considerable bleeding risk, which can occur at critical sites or lead to severe life-threatening conditions. Recent statistics indicated that major bleeding occurs in up to 6.62 DOAC users per 100 treatment years. With the increased use of DOACs in clinical practice, DOAC-associated major bleeding is expected to be encountered more frequently in the emergency department. The current international guidelines recommend specific reversal agents for the management of DOAC users with severe bleeding to reverse the anticoagulant effect and restore normal hemostasis. An individualized assessment was incorporated in specific clinical situations to guide the decision pathway of major bleeding management. However, specific reversal agents are unavailable or have limited availability in many countries, which is expected to negatively impact the clinical outcomes of DOAC-associated major bleeding. Limited real-world evidence is available from these countries regarding the clinical outcomes of patients with DOAC-associated major bleeding. This narrative review provided an updated assessment of the evidence-based approaches for the management of major bleeding in DOAC users. We also explored the clinical outcomes of patients with major bleeding from clinical settings where specific reversal agents are unavailable.

Prescribing Trends of Oral Anticoagulants from 2010 to 2020 in Shanghai, China: A Retrospective Study

Aim

Non-vitamin K antagonist oral anticoagulants (NOACs) were developed as an alternative to warfarin to prevent thromboembolism in patients with atrial fibrillation (AF), prosthetic heart valves, venous thromboembolism (VTE), or other thrombotic disorders. The aim of this study is to explore the trends in prescribing OACs, including warfarin and NOACs, in Shanghai, China.

Methods

Prescription data of OACs were retrospectively collected from Rx Analysis System from 2010 to 2020 in Shanghai, China. Comparisons were made on the trends of each OACs according to different indications, age groups, and hospital grades. The costs and the contribution of individual OACs were also explored.

Results

Growing trends in overall prescriptions for OACs were observed. The prescriptions of NOACs were significantly increased since 2016, while the prescriptions of warfarin kept decreasing since 2017. A highly statistically significant increase in prescriptions of Rivaroxaban was observed from 2016 to 2020 (P < .001). Despite the price reduction of rivaroxaban in 2018, the total cost of rivaroxaban continued to rise (P < .001). Rivaroxaban emerged as a preferred NOAC in both indications of AF and VTE, and accounted for more than three-quarters of the total costs for OACs since 2019. Compared with rivaroxaban, the prescription numbers of dabigatran and apixaban were much smaller, and the growth of prescriptions were much slower. Differences in prescribing patterns in different indications, age groups, and grades of hospitals were also founded.

Conclusion

There has been a rapid increase in the use of OAC over the last 11 years in Shanghai, China. NOACs have been adopted rapidly, and have been gradually replacing warfarin. Warfarin remains the top choice for certain patients with valvular heart disease. Future studies are warranted considering changes in the OAC use in a larger scale, as well as the rationality and its influence factors on OAC use.

Ancestry-related distribution of Runs of homozygosity and functional variants in Qatari population

Background

Describing how genetic history shapes the pattern of medically relevant variants could improve the understanding of how specific loci interact with each other and affect diseases and traits prevalence. The Qatari population is characterized by a complex history of admixture and substructure, and the study of its population genomic features would provide valuable insights into the genetic landscape of functional variants. Here, we analyzed the genomic variation of 186 newly-genotyped healthy individuals from the Qatari peninsula.

Results

We discovered an intricate genetic structure using ancestry related analyses. In particular, the presence of three different clusters, Cluster 1, Cluster 2 and Cluster 3 (with Near Eastern, South Asian and African ancestry, respectively), was detected with an additional fourth one (Cluster 4) with East Asian ancestry. These subpopulations show differences in the distribution of runs of homozygosity (ROH) and admixture events in the past, ranging from 40 to 5 generations ago. This complex genetic history led to a peculiar pattern of functional markers under positive selection, differentiated in shared signals and private signals. Interestingly we found several signatures of shared selection on SNPs in the FADS2 gene, hinting at a possible common evolutionary link to dietary intake. Among the private signals, we found enrichment for markers associated with HDL and LDL for Cluster 1(Near Eastern ancestry) and Cluster 3 (South Asian ancestry) and height and blood traits for Cluster 2 (African ancestry).

The differences in genetic history among these populations also resulted in the different frequency distribution of putative loss of function variants. For example, homozygous carriers for rs2884737, a variant linked to an anticoagulant drug (warfarin) response, are mainly represented by individuals with predominant Bedouin ancestry (risk allele frequency G at 0.48).

Conclusions

We provided a detailed catalogue of the different ancestral pattern in the Qatari population highlighting differences and similarities in the distribution of selected variants and putative loss of functions. Finally, these results would provide useful guidance for assessing genetic risk factors linked to consanguinity and genetic ancestry.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12863-022-01087-1.

Genomewide association analysis of warfarin dose requirements in Middle Eastern and North African populations

To date, there has been no genomewide association study (GWAS) from the Middle East and North African (MENA) region to identify genetic variants associated with warfarin dose variability using this approach. In this study, we aimed to conduct the first GWAS of warfarin dose requirements in patients from the MENA region. A total of 132 Qatari (discovery) and 50 Egyptians (replication) were genotyped using Illumina Multi-Ethnic Global BeadChip Array. A GWAS was performed on log-transformed weekly warfarin dose in the studied population, adjusting for clinical characteristics and ancestry. The genomewide signals from the discovery cohort were tested in the Egyptian cohort. A GWAS meta-analysis, including the Qatari and Egyptian cohorts, was also performed and the output from this analysis was used in a gene-based analysis. The discovery analysis in Qatari identified five genomewide single-nucleotide polymorphisms (SNPs) in chromosome 16. These signals were replicated in the Egyptian cohort. Combining the two data through a GWAS meta-analysis strengthened the association in chromosome 16 with VKORC1 rs9934438 being the lead genomewide signal (β = -0.17, 6 × 10-15 ). Other SNPs were identified in chromosome 10 at a p value less than 1 × 10-5 . The genetic variants within VKORC1 rs9934438 and CYP2C9 rs4086116 explained 39% and 27% of the variability in the weekly warfarin dose requirement in the Qatari and Egyptians, respectively. This is the first GWAS of warfarin dose variability in the MENA region. It confirms the importance of VKORC1 and CYP2C9 variants in warfarin dose variability among patients from the MENA region.

Causes of gastrointestinal bleeding in oral anticoagulant users compared to non-users in a population-based study

BACKGROUND/AIMS

Causes of gastrointestinal bleeding (GIB) in patients on oral anticoagulants (OACs) are not well established. The aims of the study were to compare the causes of GIB in patients on OACs and those not on OAC therapy.

METHODS

A nationwide study of all GIB events in patients on OACs in Iceland from 2014-2019 was conducted. Bleeding events were obtained through ICD-10 codes and review of endoscopy databases, confirmed by review of medical records. For comparison, patients not on OACs from previous Icelandic population-based studies were used.

RESULTS

Among 752 GIB events in 12,005 patients on OACs, 273 (1.9%) had verified upper and 391 (2.7%) had verified lower GIB. For lower GIB, multivariate analysis showed that OAC users were more likely to have colonic polyps (OR 6.6, 95% CI: 2.4 - 17.8, p < .001) or colorectal cancer (OR 3.7, 95% CI: 2.0 - 7.0, p < .001) but less likely to have ischemic colitis (OR 0.11, 95% CI: 0.04 - 0.26, p < .001). For upper GIB, bleeding from mucosal erosions (OR 4.0 95% CI: 2.5 - 7.9, p < .001) and angiodysplasia (OR 3.6, 95%CI: 1.5 - 8.6, p = .003) were more common in OAC users.

CONCLUSIONS

A high proportion of GIB caused by colonic polyps and colorectal cancer among OAC patients indicates that OACs treatment may facilitate cancer diagnosis. The low proportion of ischemic colitis among those on OACs suggests that OACs provide a protective effect against ischemic colitis. OACs seem to increase the bleeding from angiodysplasia and mucosal erosive disease.

A drug utilization study of oral anticoagulants in five representative cities of China between 2015 and 2019

WHAT IS KNOWN AND OBJECTIVE

Oral anticoagulants (OACs), including warfarin and newer direct-acting OACs (DOACs), have been used for decades to prevent thromboembolic diseases. A drug utilization study was performed to determine the prescribing patterns of OACs.

METHODS

Data were extracted from the Cooperation Project of Hospital Prescription Analysis in China. A total of 455,490 prescription records from 43 tertiary hospitals in five cities of China (Beijing, Shanghai, Guangzhou, Hangzhou and Chengdu) were selected for inclusion. Quarterly trends of defined daily doses (DDDs) and defined daily dose cost (DDDC) from 1 January 2015 to 31 December 2019 were calculated.

RESULTS AND DISCUSSION

Warfarin was the most widely used OAC with DDDs between 189,982 and 176,323 from the first quarter (Q1) of 2015 to the fourth quarter (Q4) of 2019, whereas the use of DOACs increased rapidly during this period. DDDs of rivaroxaban increased from 5409 in Q1 of 2015 to 125,800 in Q4 of 2019, whereas the DDDC declined from 160.5 to 45.7. From Q1 of 2018, rivaroxaban became the most prescribed OAC, surpassing warfarin, in patients diagnosed with deep vein thrombosis. In addition, the DDDs of rivaroxaban exceeded those of warfarin in patients diagnosed with non-valvular atrial fibrillation since the second quarter (Q2) of 2019. DDDs in outpatients and inpatients increased by 80.6% and 71.4%, respectively, and the DDDC for outpatients in Q4 of 2019 was 6.7-fold higher than that in Q1 of 2015. Among patients of all ages, the DDDs in elderly patients increased from 36.8% in Q1 of 2015 to 59.4% in Q4 of 2019. Moreover, the departments of cardiology and cardiothoracic surgery prescribed the majority of the OACs.

WHAT IS NEW AND CONCLUSION

In this study, we describe OAC prescription patterns in China. DOACs, especially rivaroxaban, contribute to the continuous increase in the use of OACs. In the investigated population of China, outpatients and elderly patients were observed to be administered the highest proportion of DOACs.

Genetic and Non-Genetic Factors Impact on INR Normalization in Preprocedural Warfarin Management

Background

Annually, 10% of warfarin patients will likely need to stop warfarin prior to elective surgery to achieve a baseline international normalization ratio (INR) level (INR ≤ 1.2) at the time of the procedure. This study explores the influence of genetic and non-genetic factors on INR normalization in the Arab (major part of Near Eastern) population in preprocedural warfarin management.

Methods

An observational prospective cohort study was designed to recruit Arab patients taking warfarin and scheduled for an elective procedure. Two INR readings were recorded. DNA extraction and genotyping of variants in CYP2C9*2, CYP2C9*3, CYP4F2*3, VKORC1*2, and FII (rs5896) and FVII (rs3093229) genes using real-time polymerase chain reaction were performed.

Results

Data from 116 patients were included in the analysis. CYP2C9 and VKORC1 genetic variants carriers required lower maintenance dose compared to non-carriers. The analysis showed that ciprofloxacin, antiplatelet medications, and INR index (INR at visit 1) are the only factors associated with the INR decline rate. Also, the proportion of CYP2C9*3 carriers with normal INR (≤1.2) on the day of surgery was significantly lower than those with wild-type genotype (28% vs 60%, p=0.013). In addition, heparin bridging, INR target, and Sudanese nationality are significant predictors of INR normalization (≤1.2) on the day of the procedure.

Conclusion

Despite the confirmed effect of genetic factors on warfarin maintenance dose, the study was not able to find a significant effect of any genetic factor on the rate of INR normalization possibly due to the small sample size. Index INR and interacting medications showed to be significant predictors of INR decline rate.

Assessment of the attitude, awareness and practice of periprocedural warfarin management among health care professional in Qatar. A cross sectional survey

It is estimated that 10-15% of oral anticoagulant (OAC) patients, would need to hold their OAC for scheduled surgery. Especially for warfarin, this process is complex and requires multi-layer risk assessment and decisions across different specialties. Clinical guidelines deliver broad recommendations in the area of warfarin management before surgery which can lead to different trends and practices among practitioners. To evaluate the current attitude, awareness, and practice among health care providers (HCPs) on warfarin periprocedural management. A multiple-choice questionnaire was developed, containing questions on demographics and professional information and was completed by187 HCPs involved in warfarin periprocedural management. The awareness median (IQR) score was moderate [64.28% (21.43)]. The level of awareness was associated with the practitioner's specialty and degree of education (P = 0.009, 0.011 respectively). Practice leans to overestimate the need for warfarin discontinuation as well as the need for bridging. Participants expressed interest in using genetic tests to guide periprocedural warfarin management [median (IQR) score (out of 10) = 7 (5)]. In conclusion, the survey presented a wide variation in the clinical practice of warfarin periprocedural management. This study highlights that HCPs in Qatar have moderate awareness. We suggest tailoring an educational campaign or courses towards the identified gaps.

Bridging vs Non-Bridging with Warfarin Peri-Procedural Management: Cost and Cost-Effectiveness Analyses

The warfarin peri-procedural management in Qatar is predominantly based on bridging (63%), compared to non-bridging. This study sought to perform a first-time cost analysis of current warfarin peri-procedural management practices, including a cost-effectiveness analysis (CEA) of predominant bridging vs predominant non-bridging practices. From the hospital perspective, a one-year decision-analytic model followed the cost and success consequences of the peri-procedural warfarin in a hypothetical cohort of 10,000 atrial fibrillation patients. Success was defined as survival with no adverse events. Outcome measures were the cost and success consequences of the 63% bridging (vs not-bridging) practice in the study setting, ie, Hamad Medical Corporation, Qatar, and the incremental cost-effectiveness ratio (ICER, cost/success) of the warfarin therapy when predominantly bridging based vs when predominantly non-bridging based. The model was based on Monte Carlo simulation, and sensitivity analyses were performed to confirm the robustness of the study conclusions. As per 63% bridging practices, the mean overall cost of peri-procedural warfarin management per patient was USD 3,260 (QAR 11,900), associated with an overall success rate of 0.752. Based on the CEA, predominant bridging was dominant (lower cost, higher effect) over the predominant non-bridging practice in 62.2% of simulated cases, with a cost-saving of up to USD 2,001 (QAR 7,303) at an average of USD 272 (QAR 993) and was cost-effective in 36.9% of cases. Being between cost-saving and cost-effective, compared to predominant non-bridging practices, the predominant use of bridging with warfarin seems to be a favorable strategy in atrial fibrillation patients.

Effect of SAMe-TT2R2 score and genetic polymorphism on the quality of anticoagulation control in Qatari patients treated with warfarin

There is no strong evidence on pharmacogenetics role on the quality of INR control after the initiation phase and on the maintenance of stable INR on the long term as measured by the time in therapeutic range (TTR). The benefit of a score such as SAMe-TT₂R₂ is that it can preemptively guide clinicians on whether to start the patient on warfarin or direct oral anticoagulant. To determine the association between genetic variants in CYP2C9, VKORC1, and CYP4F2 and TTR. To validate SAMe-TT₂R₂ score predictive ability on the quality of anticoagulation in Qatari patients. This is an observational nested case–control study that was conducted on a cohort of Qatari patients treated with warfarin with previously identified genotype for the CYP2C9, VKORC1, and CYP2F4. The sample size of this cohort was 148 patients. Mean TTR was 62.7 ± 21%. TTR was not significantly different among carriers of the CYP2C9*2 &*3, VKORC1(–1639G>A) or CYP4F2*3 compared to their non-carriers alleles. None of the factors in the SAMe-TT₂R₂ score had a significant effect on the TTR except for the female gender where TTR was significantly lower in females (n = 89) compared to males (n = 59) (59.6 ± 21% vs. 67.2 ± 20%, p = 0.03). Furthermore, patients with SAMe-TT₂R₂ score of zero had significantly better TTR compared to those with higher scores (76.5 ± 17% vs. 61.8 ± 21%, p = 0.04). Logistic regression analysis showed that high SAMe-TT₂R₂ score was the only statistically significant predicting factor of poor INR control (odds ratio (OR) 5.7, 95% confidence interval (CI) 1.1–28.3, p = 0.034). Genetic variants have no contribution to the quality of INR control. SAMe-TT₂R₂ score was predictive for the poor quality of anticoagulation in a cohort of Qatari patients.

Trends of ambulatory oral anticoagulant prescription in five major cities of China, 2012-2017

Background

The introduction of non-VKA oral anticoagulants (NOACs) has changed the landscape of preventing thromboembolism events in many countries. However, the prescription trends of oral anticoagulant (OAC) in China are still unclear, which were evaluated in this study through data extracted and summarized from 5 major cities as representatives.

Methods

This study was designed as a time-series study which was based on pharmacy prescription data. Analysis was performed on yearly aggregated visits and expenditure. The results were also stratified by indications and specialties.

Results

A total of 189,006 prescriptions of 67 hospitals in 6 years were included in the study. The average growth rates of overall visit and expenditure of OAC were 15.8 and 57.5%, respectively. The share of warfarin decreased and NOACs had taken 92% of cost, covering 28% of patients in 2017. The more frequently used NOACs were rivaroxaban and dabigatran. The use of OAC was differed by indication and specialty.

Conclusion

The use of NOACs was found increasing rapidly in both visits and cost, sharing a majority of cost with a minority of patients. Attentions should be paid on the rational use of NOACs.

Assessing Pharmacists Knowledge and Attitude Toward the Direct Oral Anticoagulants in Qatar

Pharmacists were found to play a key role in anticoagulation care. In order to make an appropriate selection and counselling regarding direct oral anticoagulants (DOACs), pharmacists should be knowledgeable and abiding by evidence-based practice. We aim in this study to assess the knowledge and practices of practicing hospital and community pharmacists in Qatar regarding DOACs and their reflection on the dispensing and patient education. A prospective cross-sectional survey was developed. It included questions on demographic and professional characteristics. Additionally, it evaluated the awareness regarding safety, efficacy, and dispensing of DOACs. Lastly, a separate question was used to address the participant’s satisfaction with their knowledge. A total response were received from 211 pharmacists participating in the survey. Overall awareness score was moderate (41.6% ± 26%). These scores were in alignment with participants’ self-satisfaction with knowledge on DOACs (72% of participants were not satisfied). Being a clinical pharmacist, of male gender, and with a board certification were factors associated with increased awareness on DOACs. Results from this survey point to the importance of having more educational activities in order to improve pharmacist’s knowledge of DOACs.

The effect of genetic and nongenetic factors on warfarin dose variability in Qatari population

The objective of this study is to estimate the prevalence of VKORC1, CYP2C9, and CYP4F2 genetic variants and their contribution to warfarin dose variability in Qataris. One hundred and fifty warfarin-treated Qatari patients on a stable dose and with a therapeutic INR for at least three consecutive clinic visits were recruited. Saliva samples were collected using Oragene DNA self-collection kit, followed by DNA purification and genotyping via TaqMan Real-Time-PCR assay. The population was stratified into derivation and validation cohorts for the dosing model. The minor allele frequency (MAF) of VKORC1 (-1639G>A) was A (0.47), while the MAF's for the CYP2C9*2 and *3 and CYP4F2*3 were T (0.12), C (0.04) and T (0.43), respectively. Carriers of at least one CYP2C9 decreased function allele (*2 or *3) required lower median (IQR) warfarin doses compared to noncarriers [24.5 (14.5) mg/week vs. 35 (21) mg/week, p < 0.001]. Similarly, carriers of each additional copy of (A) variant in VKORC1 (-1639G>A) led to reduction in warfarin dose requirement compared to noncarriers [21(7.5) vs. 31.5(18.7) vs. 43.7(15), p < 0.0001]. CYP4F2*3 polymorphism on the other hand was not associated with warfarin dose. Multivariate analysis on the derivation cohort (n = 104) showed that a dosing model consisting of hypertension (HTN), heart failure (HF), VKORC1 (-1639G>A), CYP2C9*2 & *3, and smoking could explain 39.2% of warfarin dose variability in Qataris (P < 0.001). In the validation cohort (n = 45), correlation between predicted and actual warfarin doses was moderate (Spearman's rho correlation coefficient = 0.711, p < 0.001). This study concluded that VKORC1 (-1639G>A), CYP2C9*2 & *3 are the most significant predictors of warfarin dose along with HTN, HF and smoking.

A Survey on the Awareness and Attitude of Physicians on Direct Oral Anticoagulants in Qatar

Direct oral anticoagulants (DOACs) are more commonly prescribed since their introduction. Reports on inappropriate prescribing have been observed which may indicate poor awareness on these agents. In this study, we aim to evaluate the extent of the physicians' knowledge on DOACs and its possible impact on physicians' confidence to prescribe these medications. A prospective cross-sectional survey was developed based on the literature review. Eligible participants were physicians and surgeons currently practicing at Hamad General Hospital in Qatar. The survey included questions on demographic and professional characteristics. It also evaluated the awareness and attitudes regarding safety, efficacy, and prescribing of DOACs. Over 6-month period, 175 practitioners responded to the survey. Overall awareness score was moderate (61% ± 18%). These scores were in alignment with participants' self-satisfaction with knowledge on DOACs (66% were not satisfied) and participants' confidence toward prescribing DOACs (48% were not confident). Age, degree of education, and years of experience had significant positive influence on awareness score. This survey indicates that practitioners have moderate awareness on DOACs. Future work should focus on reassessing practitioners' knowledge after providing well-designed education campaigns.

Approaches to Direct Oral Anticoagulant Selection in Practice

Direct oral anticoagulants (DOACs) carry many advantages over warfarin and are now considered first line or an alternative for mnay thromboembolic disorders. With the emergence of 5 DOAC agents to the market as well as the accumulating evidence gathered from head-to-head comparisons between the agents, we attempt to provide direction for clinicians when selecting the most appropriate DOAC agent. Important aspects such as efficacy, safety, cost effectiveness, approved indications, and other drug-related factors will be addressed to highlight the major similarities and diversities among the DOACs. When considering the safety profile of DOACs, evidence points toward apixaban as the safest followed by dabigatran and then rivaroxaban. On the other hand, dabigatran currently has the only approved antidote, idarucizumab. According to the approved DOAC indications, rivaroxaban may be favorable in European countries given its additional indication for secondary prevention of myocardial infarction. Following rivaroxaban, dabigatran and apixaban have the largest number of approved indications and lastly comes edoxaban and then betrixaban. For patients with renal impairment, betrixaban is the safest option, followed by apixaban and edoxaban, then rivaroxaban and lastly dabigatran. When considering DOAC dosing, rivaroxaban, edoxaban, and betrixaban are mainly dosed once daily compared to dabigatran and apixaban, which are dosed twice daily. However, rivaroxaban and betrixaban must be administered with food, which adds another level of complexity to the DOAC dosing. Lastly, taking into consideration drug interactions, dabigatran, edoxaban, and betrixaban have the least amount of interactions compared to apixaban and rivaroxaban. Each DOAC has its own set of features that makes it better suited than others based on the exact clinical situation. Therefore, no conclusion can be drawn to the most superior DOAC based on the aspects discussed in this review.

High number of newly initiated direct oral anticoagulant users switch to alternate anticoagulant therapy

Real-world evidence focusing on medication switching patterns amongst direct oral anticoagulant (DOACs) has not been well studied. The objective of this study is to evaluate patterns of prescription switching in non-valvular atrial fibrillation (NVAF) patients initiated on a DOAC and previously naïve to anticoagulation (AC) therapy. Data was obtained from Truven Health MarketScan^® Commercial and Medicare Supplemental database (2009-2013). AC naïve (those without prior anticoagulant use) NVAF patients initiated on a DOAC, with 6 months of continuous health plan enrollment before and after treatment initiation and maintained on continuous therapy for a minimum of 6 months were included. Of 34,022 AC naïve NVAF patients initiating a DOAC, 6613 (19.4%) patients switched from an index DOAC prescription to an alternate anticoagulant and 27,409 (80.6%) remained on the DOAC [age: 68.5 ± 11.7 vs. 67.1 ± 12.7 years, p < 0.001; males: 3781 (57.2%) vs. 17,160 (62.6%), p < 0.001]. Amongst those that switched medication, 3196 (48.3%) did so within the first 6 months of therapy. Overall, 2945 (44.5%) patients switched to warfarin, 2912 (44.0%) switched to another DOAC and 756 (11.4%) switched to an injectable anticoagulant. The highest proportion of patients switched from dabigatran to warfarin (N = 2320; 42.5%) or rivaroxaban (N = 2252; 41.3%). The median time to switch from the index DOAC to another DOAC was 309.5 days versus 118.0 days (p < 0.001) to switch to warfarin. In NVAF patients newly initiated on DOAC therapy, one in five patients switch to an alternate anticoagulant and one of every two patients do so within the first 6 months of therapy. Switching from an initial DOAC prescription to traditional anticoagulants occurs as frequently as switching to an alternate DOAC.

Pharmacists' confidence when providing pharmaceutical care on anticoagulants, a multinational survey

Background Guidelines on the management of orally anticoagulated patients are continuously evolving, leading to an increased need for pharmacists to be fully integrated in care provision. Objective To identify self-reported gaps in confidence among practicing pharmacists in the area of anticoagulation. Setting Pharmacists in different work settings in different countries. Method Cross-sectional international survey from October 2015 till November 2016 among pharmacists working in different settings to assess their level of confidence when delivering anticoagulants as well as to identify possible educational needs regarding this medication class. Validation of the survey was ensured. Results Responses from 4212 pharmacists originating from 18 countries were obtained. Pharmacists' level of confidence was significantly higher (p < 0.001) when advising patients on vitamin K antagonists (VKAs) versus non-vitamin K antagonists (NOACs). In general, hospital pharmacists displayed higher confidence levels compared to community pharmacists when advising patients on anticoagulation (p < 0.001). Two distinct patterns of confidence levels emerged relating to basic and advanced pharmaceutical care. Confidence levels when providing advanced pharmaceutical care were significantly higher for Oceania and lower for South America (p < 0.005). Conclusions Pharmacists felt more confident in supporting patients receiving VKAs compared to the more recently introduced NOACs. With the increasing use of NOACs and the risks pertaining to anticoagulation therapy, it is essential to invest in education for pharmacists to address their knowledge gaps enabling them to confidently support patients receiving oral anticoagulants.

Direct oral anticoagulants: analysis of worldwide use and popularity using Google Trends

BACKGROUND

Four direct oral anticoagulants (DOACs) have been approved for clinical use by many medicines regulatory agencies around the world. Due to increasing use of these drugs in routine practice, we planned an original study to investigate their worldwide diffusion using a popular Web-search engine.

METHODS

Two electronic searches were performed using Google Trends, the former using the keywords "warfarin" AND "heparin" AND "fondaparinux", and the latter using the keywords "warfarin" AND "dabigatran" AND "rivaroxaban" AND "apixaban" AND "edoxaban", both using the search criterion "prescription drug". No language restriction was applied, and the searches were carried out from the first date available in Google Trends (January 1^st, 2004) to present time (June 1^st, 2017).

RESULTS

The median Google Trends score of warfarin (i.e., 86) was consistently higher than that of heparin (54; P<0.001), fondaparinux (6; P<0.001), dabigatran (11; P<0.001), rivaroxaban (5; P<0.001), apixaban (1; P<0.001) and edoxaban (1; P<0.001). Specific analysis of the trends shows that the score of warfarin exhibits a highly significant decrease over time (r=-0.40; P<0.001), whilst that of heparin has remained virtually unchanged (r=0.12; P=0.127), and that of fondaparinux has marginally increased (r=0.16; P=0.038). As regards DOACs, the scores of these drugs significantly increased during the search period (dabigatran, r=0.79; rivaroxaban, r=0.99; apixaban, r=0.98; edoxaban, r=0.78; all P<0.001). When the analysis was limited to the past five years, the dabigatran score significantly decreased (r=-0.57; P<0.001), whereas that of the other DOACs exhibited an even sharper increase. Most Google searches for DOACs were performed in North America, central-eastern Europe and Australia.

CONCLUSIONS

The results of our analysis suggest that the popularity of DOACs is constantly increasing around the world, whereas that of warfarin has exhibited a constant and inexorable decline.