Anticoagulation control, outcomes, and associated factors in long-term-care patients receiving warfarin in Africa: a systematic review

Abstract

Background Oral anticoagulation therapy with warfarin requires frequent monitoring level of anticoagulation by the international normalized ratio (INR). In Africa, studies that explore anticoagulation control, treatment outcomes, and associated factors are reported in various ways in long-term patients receiving warfarin therapy to generate concrete scientific evidence. Methods The literature search was conducted in PubMed, Cochrane Library, African Journal of Online databases, Google Scholar, and Google. An advanced search strategy was computed to retrieve relevant studies related to anticoagulation control and outcomes. Duplication, title and abstract screening, and full-text assessment were conducted in Covidence software. Study quality was assessed using the Joanna Briggs Institute Critical appraisal quality assessment tool. The systematic review is registered in PROSPERO (CRD42021260772) and performed based on the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guideline. Results Out of 298 identified articles, 18 articles were eligible for the final review and analysis. The mean of 39.4 ± 8.4% time in therapeutic range (TTR) (29.4 to 57.3%), 36.7 ± 11.5% TTR (range 25.2–49.7%) and 46% TTR (43.5–48.5%) was computed from studies that determined TTR by Rosendaal, direct and cross-section-of-the-files methods, respectively. In this review, the lowest percentage of TTR was 13.7%, while the highest was 57.3%. The highest percentage of patients (32.25%) who had TTR ≥ 65% was reported in Tunisia, but the lowest percentages were in Namibia (10%, TTR ≥ 65%) and Kenya (10.4%, TTR ≥ 70%). Most of the included studies (11 out of 18) used Rosendaal’s method while the direct method was employed by three studies. Generally, 10.4–32.3% of study participants achieved desired optimal anticoagulation level. Regarding secondary outcomes, 1.6–7.5% and 0.006–59% of patients experienced thromboembolic complications and bleeding events, respectively. Having chronic comorbidities, taking more than two drugs, and presence of medications that potentially interact with warfarin, and patient-related factors (patients aged < 50 years old, female gender, lower education level, smoking history) were the frequently reported predictors of poor anticoagulation therapy. Conclusions Oral anticoagulation control was suboptimal in patients taking warfarin as evidenced by low TTR in Africa. Therefore, there is an urgent need for further improving oral anticoagulation management services.

Comparison of anticoagulation control and outcomes between usual medical care and pharmacist-led anticoagulation service in ambulatory patients taking warfarin at tertiary hospital in Ethiopia: a quasi-experimental study

“…This approach has been increasingly recognized for its capacity to provide personalized patient education, ensure consistent monitoring, and facilitate precise dosage adjustments, including the management of complex therapies, such as warfarin [ 61 ]. The difference between the outcomes of this study and the typical lower TTRs reported in African countries [ 32 ] further emphasizes the unique impact of PLAS in resource-limited settings. This finding suggests that PLAS may expand beyond high-income countries and offer a viable solution for improving anticoagulation management.…”

“…Most patients in both groups were female, with no significant differences ( p = 0.31) between the groups in each sex category. The median (IQR) age in the UMC was 41.00 [ 32 – 55 ] years, with a range of 18–82 years, while in the PLAC group, the median ± IQR of age was 39.00 [ 32 – 49 ] years, with a range of 20–85 years without any significant difference between the groups ( p = 0.15). A significant difference was observed based on the residence of the patients, and the majority of patients were residents of Addis Ababa (study area) in both the UMC and PLAC: 247 (70.6) and 148 (84.6), respectively ( p < 0.001) (Table 1 ).…”

“…However, in clinical practice, maintaining adequate anticoagulation with warfarin has proven challenging, as demonstrated by studies conducted globally documenting a low TTR (< 65%) [ 18 – 28 ]. This problem appears to be the worst in Africa because the lowest TTRs have been reported in studies conducted in various regions of the continent [ 1 , 8 , 24 , 29 – 32 ]. Lower TTRs (29–42.7%) were recorded in patients receiving warfarin in Ethiopia [ 33 – 37 ] Furthermore, a prevalence of 99.2% [ 38 ] and 21.1% ( [ 39 ] of warfarin-drug interactions were documented in two Ethiopian hospitals.…”

Rheumatic Heart Disease in the Developing World

“… 71 While mechanical valve replacement does offer benefits in terms of longevity, it is important to note that anticoagulation management is challenging in LMICs, leading to higher rates of valve thrombosis, thromboembolism, and bleeding complications than in industrialized nations. 72 Surgical options for rheumatic mitral valve disease are summarized in Figure 4 .

Figure 4 Operative Interventions for RHD .

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Ancoragem De Implantes Dentários Enxertados Com Filamentos De Álcool Polivinílico (Pva) E Ácido Polilático (Pla) Em Defeitos Ósseos in Vitro

“…geral foram de 65 ± 20% e 68% (IQR 53-79%) e na África do Sul (58,1% ± 16%). Considerados assim, bons resultados quando comparados a outros países em desenvolvimento(TADESSE et. al., 2022).…”