Improving anticoagulation in sub-Saharan Africa -- what are the challenges, and how can we overcome them?

Abstract

Patients in sub-Saharan Africa generally have poor anticoagulation control. We review the potential reasons for this poor control, as well as the potential solutions. Challenges include the affordability and centralisation of anticoagulation care, problems with access to medicines and INR monitoring, the lack of locally-validated standardized dosing protocols, and low levels of anticoagulation knowledge among health care workers and patients. Increasing numbers of patients will need anticoagulation in the future because of the epidemiological transition in the region. We propose that locally-developed "warfarin care bundles" which address multiple anticoagulation challenges in combination may be the most appropriate solution in this setting currently.

Developing and Validating a Clinical Warfarin Dose‐Initiation Model for Black‐African Patients in South Africa and Uganda

“…The need for dose‐prediction models that are applicable to sub‐Saharan African patients is emphasized by the poor quality of warfarin anticoagulation (defined as having a time in therapeutic INR range (TTR) of < 65% 5 ) in this region. In an earlier study in South Africa and Uganda, we observed that the median TTR was 41% (range 35–48%), 6 similar to previous reports in this region 7–10 . This is quite low when compared with our previous experience with an European cohort (mean TTRs of 60% (fixed‐dose initiation) and 67% (genotype‐guided dosing)) 11 .…”

“…In an earlier study in South Africa and Uganda, we observed that the median TTR was 41% (range 35-48%), 6 similar to previous reports in this region. [7][8][9][10] This is quite low when compared with our previous experience with an European cohort (mean TTRs of 60% (fixed-dose initiation) and 67% (genotype-guided dosing)). 11 To improve warfarin anticoagulation through optimizing dosing, we therefore aimed to develop and validate a clinical warfarin dose-initiation model for sub-Saharan African patients.…”

Challenges of Anticoagulation Management Service and Need of Establishing Pharmacist-Led Anticoagulation Clinic in Tertiary Care Teaching Hospital, Ethiopia: A Qualitative Study

“…Specialized anticoagulation clinics (AC) that use standardized procedures achieve better control of anticoagulation than UMC, where patients requiring anticoagulation are seen as part of the general patient population, which is not common in sub-Saharan Africa, including Ethiopia. 21 A study conducted at a Malaysian tertiary hospital by Thanimalai et al showed that patients in the warfarin medication therapy adherence clinic (WMTAC) had significantly higher actual TTR (65.1 vs 48.3%; p < 0.05), lower admission rate (6.5 vs 28.2 events per 100 person-years), and lower bleeding incidence compared with the UMC group. 13 Another systemic review and meta-analysis showed that the risk of hemorrhagic events and thrombotic events decreased significantly in pharmacist-led anticoagulation management groups compared with other management models.…”

“…To address the above service-related issues, INR testing should be performed from the point of care, a central laboratory should be established within the hospital, the waiting time for the INR test report should be shortened, and work should be done on the continuous provision of the testing service when available. 21 As commonly described by physicians and patients, the inadequate availability of anticoagulants such as warfarin in the study hospital forces patients to obtain the drugs from private sources at high cost. Furthermore, this contributes to poor adherence and suboptimal anticoagulation outcomes, which may lead to thromboembolic events.…”

Stable warfarin dose prediction in sub‐Saharan African patients: A machine‐learning approach and external validation of a clinical dose–initiation algorithm

“…Algorithms produced by the 21 machine‐learning techniques, the War‐PATH clinical dose–initiation algorithm 10 and fixed‐dose initiation (35 mg/week, common practice in sub‐Saharan Africa 20 in which dosing is started empirically at 5 mg/day) were externally validated using the War‐PATH external validation cohort ( n = 270).…”