Comparison of Three Methods to Assess Therapeutic Quality Control of Treatment with Vitamin K Antagonists

1999 ◽  
Vol 82 (10) ◽  
pp. 1260-1263 ◽  
Author(s):  
Martin Prins ◽  
W. Ken Redekop ◽  
Jan Tijssen ◽  
Siem Heisterkamp ◽  
Harry Büller ◽  
...  
Keyword(s):  
Quality Control ◽  
Vitamin K ◽  
Hybrid Method ◽  
Vitamin K Antagonists ◽  
Linear Interpolation ◽  
Target Range ◽  
Therapeutic Level

SummaryDuring treatment with vitamin K antagonists, International Normalized Ratios (INR) are determined periodically to maintain a therapeutic level of anticoagulation. We evaluated two existing methods for therapeutic quality control (linear interpolation and equidivision), with regard to their validity and reproducibility. In addition, we proposed and evaluated a (hybrid) method that takes into account potential effects of dosage modifications when INRs are far out of the target range. Validity was assessed by deleting intermediary INR results and estimating this INR based on the two surrounding INRs with each of the three methods. The estimated INRs were then compared with the observed INR.Reproducibility of time spent in an INR range was evaluated for each of the three methods by deleting at random increasing proportions of INRs and comparing these estimates with the situation without deletions. We found that estimates of time spent in INR categories obtained with equidivision were most reproducible, but least valid. The hybrid method showed slightly higher validity and reproducibility in comparison with linear interpolation. Since these differences were small, linear interpolation is preferable to the hybrid method, since the calculations involved are easier.

Control of anticoagulation with vitamin K antagonists: overestimation of median time in therapeutic range when assessed by linear interpolation

2016 ◽  
Vol 116 (10) ◽  
pp. 679-686 ◽  
Author(s):  
Felix J. M. van der Meer ◽  
Henk J. Adriaansen ◽  
Frank W. G. Leebeek ◽  
Marieke J. H. A. Kruip ◽  
A. M. H. P. van den Besselaar ◽  
...  
Keyword(s):  
Vitamin K ◽  
Therapeutic Range ◽  
Vitamin K Antagonists ◽  
Linear Interpolation ◽  
Target Range ◽  
Rank Test ◽  
Induction Phase ◽  
Time In Therapeutic Range ◽  
Significant Difference

SummaryPatients receiving vitamin K–antagonists are monitored by regular assessment of the International Normalized Ratio (INR). There are two popular methods for therapeutic control of anticoagulation in patient groups: 1) Time in Therapeutic Range (TTR) assessed by linear interpolation of successive INR measurements; 2) the cross-sectional proportion (CSP) of all patients’ last INRs within range. The purpose of the present study is to compare the two methods using data from 53 Dutch Thrombosis Centres and to develop a semi-quantitative model for TTR based on different types of INR change. Different groups of around 400,000 patients in four consecutive years were evaluated: patients in the induction phase, short-term, long-term, low-target range, high-target range, receiving either acenocoumarol or phenprocoumon, and performing self-management. Each Centre provided TTR and CSP results for each patient group. TTR and CSP were compared using the Wilcoxon signed-rank test. Separately, we analysed the relationship between consecutive INR results regarding in or out of range and their frequency of occurrence in patients of two different cohorts. Good correlation was observed between TTR and CSP (correlation coefficient 0.694–0.950 in low-target range). In long-term acenocoumarol patients (low-target range) the median TTR was significantly higher than CSP (80.0 % and 78.7 %, respectively; p<0.001). In long-term phenprocoumon patients (low-target range) there was no significant difference between median TTR (83.0 %) and median CSP (82.6 %). In conclusion, the correlation between TTR assessed by linear interpolation and CSP was good. TTR assessed by linear interpolation was higher than CSP in patients on acenocoumarol.

Quality control of oral anticoagulation with vitamin K antagonists in primary care patients in Poland: a multi-centre study

2018 ◽  
pp. 764-769 ◽  
Author(s):  
Jolanta Sawicka-Powierza ◽  
Krzysztof Buczkowski ◽  
Sławomir Chlabicz ◽  
Zbigniew Gugnowski ◽  
Katarzyna Powierza ◽  
...  
Keyword(s):  
Primary Care ◽  
Quality Control ◽  
Vitamin K ◽  
Oral Anticoagulation ◽  
Vitamin K Antagonists ◽  
Multi Centre Study ◽  
Centre Study ◽  
Primary Care Patients

scholarly journals Effectivity of a joint didactic intervention by School for Patients on inappropriate control prothrombin time anticoagulated patients. Protocol for developing a randomized and controlled clinical trial.

2020 ◽  
Author(s):  
Leovigildo Ginel-Mendoza ◽  
Alfonso Hidalgo Hidalgo-Natera ◽  
Rocio Reina-Gonzalez ◽  
Rafael Poyato-Ramos ◽  
Inmaculada Lupianez-Perez ◽  
...  
Keyword(s):  
Social Support ◽  
Clinical Trial ◽  
Prothrombin Time ◽  
Vitamin K ◽  
Oral Anticoagulant ◽  
Vitamin K Antagonists ◽  
International Normalized Ratio ◽  
Control Group ◽  
Therapeutic Level ◽  
Anticoagulated Patients

Abstract Background Oral anticoagulant drugs represent an essential tool in thrombo-embolic events prevention. Most used are vitamin K antagonists, whose plasma level is monitored by measuring prothrombin time using the International Normalized Ratio. If it takes values out of the recommended range, the patient will have a higher risk of suffering from thromboembolic or hemorrhagic complications. Previous research has shown that about 33% of total patients keep values on inappropriate level. The purpose of the study is to improve International Normalized Ratio control figures by a joint didactic intervention based on the Junta de Andalucía School for Patients method that will be implemented by anticoagulated patients themselves. Methods A randomized clinical trial was carried out at primary care centers from one healthcare area in Málaga (Andalusia, Spain). Study population: patients included in an oral anticoagulant therapy program consisting in using vitamin K antagonists. First step detection of patients on oral anticoagulation program with International Normalized Ratio control on therapeutic level during 65% or less over total time. Second step: patients with inappropriate International Normalized Ratio control were included in two groups: Group 1 or Joint Intervention Group: patients were instructed a joint didactic intervention “from peer to peer”, by a previously trained and expert anticoagulated patient. Group 2 or Control Group: Control group performed usual clinical practice: people were schedule by nurses about one time per month, except cases in which controls were inappropriate; in those circumstances patients were schedule before that period expired. In order to built the study group and the control group, 312 individuals were required (156 in each group) to detect differences in INR figures equal or higher than 15% between both groups. Study variables time on therapeutic levels before and after intervention, sociodemographic variables, vital signs, existence of cardiovascular risk factors or accompanying diseases in the clinical records, laboratory test including complete blood count, bleeding time, and prothrombin time or partial thromboplastin time and blood chemistry, other prescribed drugs, and social support. Almost-experimental analytic study with before-after statistical analysis of the intervention were made. Lineal regression models were applied on main variables results (International Normalized Ratio value, time on therapeutic level) inputting sociodemographic variables, accompanying diseases and social support.

Tendency towards Minor Bleeding in Women Is Associated with a Reduced Risk for Major Bleeding, without Apparent Differences in Level of Anticoagulation during Treatment with Vitamin K Antagonist.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 889-889
Author(s):  
Nic J.G.M. Veeger ◽  
Margriet Piersma-Wichers ◽  
Jan van der Meer
Keyword(s):  
Vitamin K ◽  
Major Bleeding ◽  
Vitamin K Antagonists ◽  
Secondary Prophylaxis ◽  
Incidence Rates ◽  
Target Range ◽  
Minor Bleeding ◽  
Bleeding Tendency ◽  
Men And Women ◽  
Reduced Risk

Abstract Easy bruising is frequently found in healthy women. This mild bleeding tendency may be enhanced by treatment with vitamin K antagonists. This may result in more intense monitoring of the level of anticoagulation (INR) to improve the individual time within target range (ITTR) and consequently to reduce the risk of major bleeding. We performed a retrospective study in 6758 consecutive patients receiving vitamin K antagonists for primary or secondary prophylaxis of venous or arterial thrombosis (mean age 67, 51% male and 189762 INRs in 6681 person-years) to evaluate differences in gender on the occurrence of minor and major bleeding, as well as the ITTR. The incidence rates (IR, per 100 person-years) of minor and major bleeding were assessed and survival analysis performed to obtain adjusted hazard ratios (HR, 95%CI) for major bleeding in men versus women with or without prior minor bleeding, controlling for significant patient characteristics. Minor bleeding occurred more frequently in women than men (IR=33.2 versus 21.1, respectively; HR=1.5, 95%CI 1.4–1.7, p<0.001), whereas major bleeding showed a tendency towards a higher incidence in men (IR=1.6 versus 2.0; HR=1.3, 95%CI 0.9–1.8, p=0.20). Figure Figure However, in women with prior minor bleeding, the incidence of major bleeding was low (IR=1.3, 95% CI 0.7–2.1), when compared to men with minor bleeding (3.3, 95%C 2.2–4.7) (HR =2.7, 95% CI 1.4–5.0, p=0.002). Men and women without prior minor bleeding had comparable incidences of major bleeding (IR 1.8, 95% CI 1.3–2.5, and 1.5, 95% CI 1.1–2.1, respectively), but both were higher than in women with prior minor bleeding (HR 1.4 (0.8–2.5, p=0.30 and 1.2 (0.7–2.2, p=0.55)). These differences were even more pronounced in patients at high risk of major bleeding due to a strongly reduced ITTR (ITTR below 30%, lowest quartile). Considering the actually achieved level of anticoagulation, there were no differences between men and women with or without prior minor bleeding that could explain the reduced risk of major bleeding in women with prior minor bleeding. With 42% to 43%, the ITTR was comparable, as was the time spend above INR 5.0 (6% to 7%). In conclusion, more frequent minor bleeding in women was associated with a reduced incidence of major bleeding, whereas in men, such a reversed association was not present. Differences in intensity of INR monitoring in patients with or without minor bleeding and as a result in actual level of anticoagulation, could not be demonstrated.

scholarly journals The impact of acute diarrhea on the coagulation status of patients with vitamin K antagonists

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Johannes Schweinfurth ◽  
Alexander Bauer ◽  
Frederic Bauer ◽  
Felix Sebastian Seibert ◽  
Benjamin Rohn ◽  
...  
Keyword(s):  
Vitamin K ◽  
Acute Diarrhea ◽  
Data Extraction ◽  
Vitamin K Antagonists ◽  
Target Range ◽  
Close Monitoring ◽  
Exclusion Criteria ◽  
Increased Risk ◽  
Coagulation Status ◽  
The Impact

AbstractAcute diarrhea is associated with a reduced absorption of both vitamin K antagonists (VKA) and vitamin K itself. To date, the net effect on the coagulation status of subjects with VKA remains elusive. We performed a systematic retrospective single-center analysis using an electronic data extraction approach to identify subjects with plasmatic anticoagulation (either VKA or direct oral anticoagulant (DOAC)) and diarrhea in a German University Hospital over a period of eight years. Acute diarrhea and complete documentation of coagulation status on admission were defined as inclusion criteria, anticoagulation other than VKA/DOAC and obvious inadherence as exclusion criteria. Subjects with VKA/DOAC admitted for hypertension served as control group. Data extraction yielded 356 subjects with gastrointestinal diagnoses and 198 hypertensive subjects, 55 and 83 of whom fulfilled all in- and exclusion criteria. INR values of subjects with VKA were significantly higher in subjects with diarrhea than in hypertensive controls (4.3 ± 3.7 vs. 2.3 ± 0.7, p < 0.001). The distribution of subjects having INR values lower, higher or within the target range differed significantly among groups with a substantially higher prevalence of overanticoagulation in the diarrhea group (46.4% vs. 14.3%, p < 0.001). In a multinomial logistic regression model, acute diarrhea was significantly associated with overanticoagulation (odds ratio 7.2, 95% confidence interval 2.163–23.921; p < 0.001), whereas age, sex, creatinine, and indication of anticoagulation were not (p > 0.05 each). Acute diarrhea is associated with a highly increased risk for overanticoagulation in patients with VKA. Thus, gastroenteritis necessitates a close monitoring of INR in order to identify subjects needing a temporary pause of VKA therapy.

Anticoagulation quality control in Primary Care with vitamin K antagonists

2017 ◽  
Vol 148 (12) ◽  
pp. 571-572
Author(s):  
Juan Carlos Aguirre Rodriguez ◽  
Manuel Jimenez de la Cruz ◽  
Abraham Hidalgo Rodríguez
Keyword(s):  
Primary Care ◽  
Quality Control ◽  
Vitamin K ◽  
Vitamin K Antagonists

Idiopathic venous thrombosis

2006 ◽  
Vol 26 (01) ◽  
pp. 52-54 ◽  
Author(s):  
P. A. Kyrle
Keyword(s):  
Chronic Disease ◽  
Venous Thrombosis ◽  
Vitamin K ◽  
Clinical Benefit ◽  
Plasma Levels ◽  
Vitamin K Antagonists ◽  
Antithrombin Deficiency ◽  
Optimal Duration ◽  
Risk Of Treatment

SummaryVenous thrombosis is a chronic disease with a recurrence rate of approximately 30% within 5-8 years. The optimal duration of secondary thromboprophylaxis in these patients entails balancing the risk of recurrence against the risk of treatment-associated bleeding. There is agreement that patients with a first idiopathic venous thrombosis should receive vitamin K antagonists for at least 3-6 months. Convincing trials showing a clinical benefit in terms of morbidity or mortality with respect to expansion of anticoagulation beyond 6 months are lacking. Nevertheless, some subgroups of patients with venous thrombosis may benefit from indefinite anticoagulation. Thus, patients with antithrombin deficiency, combined or homozygous defects, more than one unprovoked episode of thrombosis, the lupus anticoagulant or high factor VIII plasma levels are good candidates for long-term prevention.

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