Uwe Taborski

Self-Management of oral Anticoagulation in nonvalvular Atrial Fibrillation (SMAAF study)

Der Großteil der Patienten mit Vorhofflimmern ist durch ein thromboembolisches Ereignis gefährdet. Die Komplikationsrate kann durch eine effiziente Antikoagulation um zwei Drittel reduziert werden. Ob die Qualität der Therapieüberwachung durch das Selbstmanagement bei Patienten mit Vorhofflimmern (SMAAF-Studie) im Vergleich zur herkömmlichen bei Hausarzt betreuten Patienten verbessert werden kann, war Gegenstand dieser prospektiven Multicenter- Studie. Bei Eignung zum Selbstmanagement sollten 2 000 Patienten in die beiden Studienarme randomisiert werden. Im Untersuchungszeitraum von 12/99 bis 07/01 gaben lediglich 202 Patienten (64,3±9,2 Jahre, 69,3% Männer) ihr Einverständnis. Bei vorzeitigem Studienabbruch aufgrund zu niedriger Patientenzahl beschränkt sich der Gruppenvergleich auf die Auswertung gemessener INR-Werte mittels zweiseitigem t-Test. Von den 202 eingeschlossenen Patienten wurden 101 der Selbstmanagement-Gruppe (64,6±9,6 Jahre, 71,4% Männer) und 101 (64,1±8,9 Jahre, 61,4% Männer, n.s.) der Hausarztgruppe zugeordnet. Die Gesamtzahl der INR-Messungen betrug 2 865, wobei 2 072 auf Patienten im Selbstmanagement und 793 auf die Hausarztgruppe entfielen. Die Werte lagen bei Patienten im Selbstmanagement mit 67,8% im Vergleich zur Hausarztgruppe mit 58,5% signifikant häufiger (p=0,0061) im Zielbereich. Bezüglich der Verweildauer im therapeutischen Bereich bestand zwar ein Trend zugunsten der Selbstmanagement-Gruppe, jedoch kein signifikanter Unterschied (178,8±126 Tage vs. 155,9±118,4 Tage). In der Selbstmanagement- Gruppe traten zwei schwere Blutungen, in der Hausarztgruppe ein thromboembolisches Ereignis auf. Die Therapieüberwachung der oralen Antikoagulation durch das INR-Selbstmanagement ist bei Patienten mit Vorhofflimmern der Betreuung durch den Hausarzt nicht unterlegen. Most patients with atrial fibrillation are at risk of suffering thromboembolic events. This risk can be reduced by twothirds by efficient anticoagulation. This prospective multi-center trial investigated whether the quality of treatment can be improved by self-management in patients with atrial fibrillations (SMAAF Study) compared to conventional patient management by the family doctor. Two thousand patients suitable for self-manage- ment were to be randomized into the two arms of the study. In the period of investigation from December 1999 to July 2001, only 202 patients (64.3±9.2 years, 69.3% men) consented to participate. The study was discontinued prematurely since the number of patients was too low. As a consequence, the group comparison is confined to the evaluation of the INR values measured using the two-tailed t test. Of the 202 patients included, 101 were assigned to the self-management group (64.6±9.6 years, 71.4% men) and 101 (64.1±8.9 years, 61.4% men, n.s.) were assigned to the group managed by the family doctor. The total number of INR measurements was 2 865. This comprised 2 072 measurements in patients under self-management and 793 in the family doctor group. The values were within the target range significantly more frequently (p=0.0061) in patients under self-management (67.8%) as compared to the family doctor group (58.5%). There was a trend with regard to the time within target range, but the difference was not significant (178.8±126 days as compared to 155.9±118.4 days). In the self-management group, there were two severe hemorrhages, and there was one thromboembolic event in the family doctor group. Management of oral anticoagulation by INR self-management in patients with atrial fibrillation is not inferior to conventional care.

Analytical Performance of the New Coagulation Monitoring System INRatio™ for the Determination of INR Compared with the Coagulation Monitor Coaguchek® S and an Established Laboratory Method

An evaluation of the INRatio™ Prothrombin Time Monitoring system for determination of INR was done in two centers with a total of 5 healthy subjects and 77 subjects on oral anticoagulation. The INRatio™ and the Coaguchek® S were compared with an established laboratory method. The correlation coefficient of the comparison with the laboratory was r = 0.954 for INRatio™ and r = 0.937 for Coaguchek® S. The mean relative deviation from the lab method calculated according to Hill was 6.87% for INRatio™, which is rated “very goo”, and 9.72% for Coaguchek® S (“goo”). The imprecision in the normal range (INR = 1.1) showed a coefficient of variation (CV) of 7.8% and a standard deviation (SD) of 0.09. In the therapeutic range (INR 3.9) the CV was 5.4%, the SD 0.21 and above therapeutic range (INR 5.3), the CV was 8.4% (SD 0.44), rated satisfactory. The concordances of the compared methods with the routine were 81% for INRatio™ and 79% for Coaguchek® S, which is considered state-of-the-art. Most of the patients’ perceptions of the INRatio™ were very positive.In the hands of professionals the INRatio™ demonstrated very good accuracy and precision and an excellent technical reliability. Further studies using INRatio™ for self testing by patients are warranted.

Self management of oral anticoagulation with the IN Ratio system: impact of a structured teaching program on patient's knowledge of medical background and procedures.

Background Self management of oral anticoagulation (OAC) decreases complication rates and improves quality of life. Manual and cognitive abilities of patients and patient training in a structured format are a precondition for this concept. Up to now, there is no evidence about knowledge increase from teaching programs. Methods Seventy-six patients (mean age, 57.4 years, 71% male) who started long-term OAC were included in the prospective multi-center study at three teaching centers representing different populations of anticoagulation patients: a department of cardiovascular surgery, an inpatient rehabilitation center and an anticoagulation clinic. The patients were trained in a structured education program for two days. For the evaluation, the patients performed standardized tests including 16 questions prior to start (T0), after each training unit (T1/T2) and 6 weeks later (T3). The primary endpoint was the percentage of > 75% of patients who could answer > 50% of questions correctly at T3. Secondary endpoints were the overall and item-specific percentages of correct answers at the end of each training unit (T1, T2) and at T3. In addition, the teaching program was rated by the patients on a six-point rating scale. Results Seventy-four out of 76 patients gave at least 50% correct answers at T3 (97.4%; 95% confidence interval, 90.8–99.7%). The average rates of correct answers developed from 40% (T0), 86% (T1), 94% (T2) to 96% (T3). The greatest increase of knowledge was observed with blood components, interpretation of International Normalized Ratio (INR) value, and the interaction of anticoagulation with other variables (e.g. drugs or infection). Patients rated the teaching program between 1 (best rating) and 2 at all time points. At T3, the patients reported less fear of complications and less limitations in their daily life than in earlier evaluations. Conclusion The structured training program IN Ratio appears to be an appropriate instrument for instruction of INR self management. In comparison with baseline knowledge, the percentage of correctly answered questions was twice as high directly after the end of training and remained at a high level of > 90% for at least 6 weeks.

ProTime self-management yielding improvement of fluency and quality of life

Patient self-management (PSM), as the standard of care for vitamin K-antagonist therapy management in Germany requires a detailed, point-of-care (POC) device-specific training program to ensure quality patient care. In a multi-center trial using the ProTime System (Training program plus POC device), 105 patients were enrolled to evaluate efficacy of training, knowledge retention, patient satisfaction and quality of life (QoL). Patients returned to the centers 1, 3 and 6 months after training to complete questionnaires and demonstrate INR test proficiency. Training assessment employed self-evaluation and comparison of POC results between PSM and professional operators. Patient satisfaction and QoL were assessed using a modification of the questionnaire described by Sawicki and the SF12v2 QoL Survey, respectively. Patients demonstrated statistically significant improvements in knowledge post training (p < 0.001) and retained the acquired information (p = NS vs. post-training; N = 45) after 6 months. Trained patients yielded equivalent INR results to professional operators (r = 0.92) with little or no bias across all clinic visits. Compliance with weekly testing improved from 1 to 3 months (p = 0.03), remaining at the required weekly frequency through 6 months. Average patient satisfaction improved significantly during the first month and remained constant thereafter. There was a statistically significant improvement in the Physical Component Summary of SF12 between baseline and 3/6 month assessments in all centers. In conclusion, PSM requires a comprehensive system including appropriate disease and POC device training. Such a system fosters compliance, improved knowledge about underlying disease, patient satisfaction and QoL.

Rechnergestützte Dosierung in der Antikoagulationstherapie mit Phenprocoumon

UNLABELLEDnA 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.nnnRESULTSnComparison 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.nnnCONCLUSIONnGuiding 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.Der in Voruntersuchungen entwickelte Mehrparameter-Dosisrechner (TheMa) fur das Management der Antikoagulation mit Phenprocoumon wurde in einer prospektiven Untersuchung bei 22 Patienten getestet. Facharztlich und rechnergestutzt festgelegte Dosierungen wurden anhand der real und modellhaft kalkulierten INR-Werte miteinander verglichen. Zusatzlich wurde untersucht, ob mittels des zugrunde liegenden mathematischen Modells bei Absetzen der Antikoagulation der optimale Zeitpunkt fur die Durchfuhrung eines operativen Eingriffs vorhergesagt werden kann. Ergebnisse: Beim Vergleich Facharzt versus Dosisrechner fand sich mittels der drei gewahlten Qualitatsgrosen eine fast identische Genauigkeit: Polygonzug-Integrationsmethode (Grose der Abweichflache vom Zielbereich) 616,17 vs. 607,86, INR-Trefferquote im Zielbereich 166 vs. 161, TTR (time in therapeutic range) 63,91% vs. 62,40%. Die Vorhersage des idealen Interventionszeitpunktes mittels Dosisrechner ergab im Vergleich zu den real in der Auslaufkurve gemessenen Werten beim INR-Wert 1,8 eine Abweichung von 0,50 ± 0,59 Tagen. Schlussfolgerung: Der Dosisrechner zur Antikoagulationeinstellung zeigte im Vergleich zum Facharzt gleich gute Ergebnisse. Bei Pausieren der Antikoagulation ist der ideale Zeitpunkt fur Operation oder Bridging kalkulierbar.

Computer aided dosage management of phenprocoumon anticoagulation therapy. Clinical validation

UNLABELLEDnA 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.nnnRESULTSnComparison 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.nnnCONCLUSIONnGuiding 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.Der in Voruntersuchungen entwickelte Mehrparameter-Dosisrechner (TheMa) fur das Management der Antikoagulation mit Phenprocoumon wurde in einer prospektiven Untersuchung bei 22 Patienten getestet. Facharztlich und rechnergestutzt festgelegte Dosierungen wurden anhand der real und modellhaft kalkulierten INR-Werte miteinander verglichen. Zusatzlich wurde untersucht, ob mittels des zugrunde liegenden mathematischen Modells bei Absetzen der Antikoagulation der optimale Zeitpunkt fur die Durchfuhrung eines operativen Eingriffs vorhergesagt werden kann. Ergebnisse: Beim Vergleich Facharzt versus Dosisrechner fand sich mittels der drei gewahlten Qualitatsgrosen eine fast identische Genauigkeit: Polygonzug-Integrationsmethode (Grose der Abweichflache vom Zielbereich) 616,17 vs. 607,86, INR-Trefferquote im Zielbereich 166 vs. 161, TTR (time in therapeutic range) 63,91% vs. 62,40%. Die Vorhersage des idealen Interventionszeitpunktes mittels Dosisrechner ergab im Vergleich zu den real in der Auslaufkurve gemessenen Werten beim INR-Wert 1,8 eine Abweichung von 0,50 ± 0,59 Tagen. Schlussfolgerung: Der Dosisrechner zur Antikoagulationeinstellung zeigte im Vergleich zum Facharzt gleich gute Ergebnisse. Bei Pausieren der Antikoagulation ist der ideale Zeitpunkt fur Operation oder Bridging kalkulierbar.

Computer aided dosage management of phenprocoumon anticoagulation therapy: Clinical validation@@@Validierung für den klinischen Einsatz

UNLABELLEDnA 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.nnnRESULTSnComparison 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.nnnCONCLUSIONnGuiding 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.Der in Voruntersuchungen entwickelte Mehrparameter-Dosisrechner (TheMa) fur das Management der Antikoagulation mit Phenprocoumon wurde in einer prospektiven Untersuchung bei 22 Patienten getestet. Facharztlich und rechnergestutzt festgelegte Dosierungen wurden anhand der real und modellhaft kalkulierten INR-Werte miteinander verglichen. Zusatzlich wurde untersucht, ob mittels des zugrunde liegenden mathematischen Modells bei Absetzen der Antikoagulation der optimale Zeitpunkt fur die Durchfuhrung eines operativen Eingriffs vorhergesagt werden kann. Ergebnisse: Beim Vergleich Facharzt versus Dosisrechner fand sich mittels der drei gewahlten Qualitatsgrosen eine fast identische Genauigkeit: Polygonzug-Integrationsmethode (Grose der Abweichflache vom Zielbereich) 616,17 vs. 607,86, INR-Trefferquote im Zielbereich 166 vs. 161, TTR (time in therapeutic range) 63,91% vs. 62,40%. Die Vorhersage des idealen Interventionszeitpunktes mittels Dosisrechner ergab im Vergleich zu den real in der Auslaufkurve gemessenen Werten beim INR-Wert 1,8 eine Abweichung von 0,50 ± 0,59 Tagen. Schlussfolgerung: Der Dosisrechner zur Antikoagulationeinstellung zeigte im Vergleich zum Facharzt gleich gute Ergebnisse. Bei Pausieren der Antikoagulation ist der ideale Zeitpunkt fur Operation oder Bridging kalkulierbar.

Computer aided dosage management of phenprocoumon anticoagulation therapy

UNLABELLEDnA 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.nnnRESULTSnComparison 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.nnnCONCLUSIONnGuiding 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.Der in Voruntersuchungen entwickelte Mehrparameter-Dosisrechner (TheMa) fur das Management der Antikoagulation mit Phenprocoumon wurde in einer prospektiven Untersuchung bei 22 Patienten getestet. Facharztlich und rechnergestutzt festgelegte Dosierungen wurden anhand der real und modellhaft kalkulierten INR-Werte miteinander verglichen. Zusatzlich wurde untersucht, ob mittels des zugrunde liegenden mathematischen Modells bei Absetzen der Antikoagulation der optimale Zeitpunkt fur die Durchfuhrung eines operativen Eingriffs vorhergesagt werden kann. Ergebnisse: Beim Vergleich Facharzt versus Dosisrechner fand sich mittels der drei gewahlten Qualitatsgrosen eine fast identische Genauigkeit: Polygonzug-Integrationsmethode (Grose der Abweichflache vom Zielbereich) 616,17 vs. 607,86, INR-Trefferquote im Zielbereich 166 vs. 161, TTR (time in therapeutic range) 63,91% vs. 62,40%. Die Vorhersage des idealen Interventionszeitpunktes mittels Dosisrechner ergab im Vergleich zu den real in der Auslaufkurve gemessenen Werten beim INR-Wert 1,8 eine Abweichung von 0,50 ± 0,59 Tagen. Schlussfolgerung: Der Dosisrechner zur Antikoagulationeinstellung zeigte im Vergleich zum Facharzt gleich gute Ergebnisse. Bei Pausieren der Antikoagulation ist der ideale Zeitpunkt fur Operation oder Bridging kalkulierbar.