Experts , however , have commented that there may be under-utilization of OAT due to patient factors , physician factors , or regional practice variations and that sub-optimal patient management may also occur .
These models are not suitable for all patients and require the identification and education of suitable c and i date s. Potential advantages of POC devices include improved convenience to patients , better treatment compliance and satisfaction , more frequent monitoring and fewer thromboembolic and hemorrhagic complications .
Potential disadvantages of the device include the tendency to underestimate high INR values and overestimate low INR values , low thromboplastin sensitivity , inability to calculate a mean normal PT , and errors in INR determination in patients with antiphospholipid antibodies with certain instruments .
Although treatment satisfaction and quality of life ( QoL ) may improve with POC INR monitoring , some patients may experience increased anxiety or preoccupation with their disease with these strategies .
The majority of studies reported favourable impacts of POC INR monitoring on QoL and found better treatment satisfaction with POC monitoring .
UNLABELLED SUBJECT OF THE EVIDENCE -BASED ANALYSIS : The purpose of this evidence based analysis report is to examine the safety and effectiveness of point-of-care ( POC ) international normalized ratio ( INR ) monitoring devices for patients on long-term oral anticoagulation therapy ( OAT ) .
CLINICAL NEED TARGET POPULATION AND CONDITION Long-term OAT is typically required by patients with mechanical heart valves , chronic atrial fibrillation , venous thromboembolism , myocardial infa rct ion , stroke , and /or peripheral arterial occlusion .
It is estimated that approximately 1 % of the population receives anticoagulation treatment and , by applying this value to Ontario , there are an estimated 132,000 patients on OAT in the province , a figure that is expected to increase with the aging population .
Patients on OAT  are regularly monitored and their medications adjusted to ensure that their INR scores remain in the therapeutic range .
This can be challenging due to the narrow therapeutic window of warfarin and variation in individual responses .
Optimal INR scores depend on the underlying indication for treatment and patient level characteristics , but for most patients the therapeutic range is an INR score of between 2.0 and 3.0 .
There is currently no population -based Ontario data to permit the assessment of patient care , but recent systematic review s have estimated that less that 50 % of patients receive OAT on a routine basis and that patients are in the therapeutic range only 64 % of the time .
OVERVIEW OF POC INR DEVICES POC INR devices offer an alternative to laboratory-based testing and venipuncture , enabling INR determination from a fingerstick sample of whole blood .
Independent evaluations have shown POC devices to have an acceptable level of precision .
They permit INR results to be determined immediately , allowing for more rapid medication adjustments .
POC devices can be used in a variety of setting s including physician offices , ACCs , long-term care facilities , pharmacies , or by the patients themselves through self-testing ( PST ) or self-management ( PSM ) techniques .
With PST , patients measure their INR values and then contact their physician for instructions on dose adjustment , whereas with PSM , patients adjust the medication themselves based on pre-set algorithms .
EffectivenessDoes POC INR monitoring improve clinical outcomes in various setting s compared to st and ard laboratory-based testing?Does POC INR monitoring impact patient satisfaction , QoL , compliance , acceptability , convenience compared to st and ard laboratory-based INR determination ?
Cost-effectivenessWhat is the cost-effectiveness of POC INR monitoring devices in various setting s compared to st and ard laboratory-based INR determination ?
ANTICOAGULATION CONTROL Anticoagulation control is measured by the percentage of time INR is within the therapeutic range or by the percentage of INR values in the therapeutic range .
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 ) i m Vergleich zur herkömmlichen bei Hausarzt betreuten Patienten verbessert werden kann , war Gegenst and dieser prospektiven Multicenter- Studie . Bei Eignung zum Selbstmanagement sollten 2 000 Patienten in die beiden Studienarme r and omisiert werden . I m 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 i m Selbstmanagement und 793 auf die Hausarztgruppe entfielen . Die Werte lagen bei Patienten i m Selbstmanagement mit 67,8 % i m Vergleich zur Hausarztgruppe mit 58,5 % signifikant häufiger ( p=0,0061 ) i m Zielbereich . Bezüglich der Verweildauer i m therapeutischen Bereich best and 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 prospect i ve 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 thous and patients suitable for self-manage- ment were to be r and omized 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
Experts , however , have commented that there may be under-utilization of OAT due to patient factors , physician factors , or regional practice variations and that sub-optimal patient management may also occur .
These models are not suitable for all patients and require the identification and education of suitable c and i date s. Potential advantages of POC devices include improved convenience to patients , better treatment compliance and satisfaction , more frequent monitoring and fewer thromboembolic and hemorrhagic complications .
Potential disadvantages of the device include the tendency to underestimate high INR values and overestimate low INR values , low thromboplastin sensitivity , inability to calculate a mean normal PT , and errors in INR determination in patients with antiphospholipid antibodies with certain instruments .
Although treatment satisfaction and quality of life ( QoL ) may improve with POC INR monitoring , some patients may experience increased anxiety or preoccupation with their disease with these strategies .
The majority of studies reported favourable impacts of POC INR monitoring on QoL and found better treatment satisfaction with POC monitoring .
UNLABELLED SUBJECT OF THE EVIDENCE -BASED ANALYSIS : The purpose of this evidence based analysis report is to examine the safety and effectiveness of point-of-care ( POC ) international normalized ratio ( INR ) monitoring devices for patients on long-term oral anticoagulation therapy ( OAT ) .
CLINICAL NEED TARGET POPULATION AND CONDITION Long-term OAT is typically required by patients with mechanical heart valves , chronic atrial fibrillation , venous thromboembolism , myocardial infa rct ion , stroke , and /or peripheral arterial occlusion .
It is estimated that approximately 1 % of the population receives anticoagulation treatment and , by applying this value to Ontario , there are an estimated 132,000 patients on OAT in the province , a figure that is expected to increase with the aging population .
Patients on OAT  are regularly monitored and their medications adjusted to ensure that their INR scores remain in the therapeutic range .
This can be challenging due to the narrow therapeutic window of warfarin and variation in individual responses .
Optimal INR scores depend on the underlying indication for treatment and patient level characteristics , but for most patients the therapeutic range is an INR score of between 2.0 and 3.0 .
There is currently no population -based Ontario data to permit the assessment of patient care , but recent systematic review s have estimated that less that 50 % of patients receive OAT on a routine basis and that patients are in the therapeutic range only 64 % of the time .
OVERVIEW OF POC INR DEVICES POC INR devices offer an alternative to laboratory-based testing and venipuncture , enabling INR determination from a fingerstick sample of whole blood .
Independent evaluations have shown POC devices to have an acceptable level of precision .
They permit INR results to be determined immediately , allowing for more rapid medication adjustments .
POC devices can be used in a variety of setting s including physician offices , ACCs , long-term care facilities , pharmacies , or by the patients themselves through self-testing ( PST ) or self-management ( PSM ) techniques .
With PST , patients measure their INR values and then contact their physician for instructions on dose adjustment , whereas with PSM , patients adjust the medication themselves based on pre-set algorithms .
EffectivenessDoes POC INR monitoring improve clinical outcomes in various setting s compared to st and ard laboratory-based testing?Does POC INR monitoring impact patient satisfaction , QoL , compliance , acceptability , convenience compared to st and ard laboratory-based INR determination ?
Cost-effectivenessWhat is the cost-effectiveness of POC INR monitoring devices in various setting s compared to st and ard laboratory-based INR determination ?
ANTICOAGULATION CONTROL Anticoagulation control is measured by the percentage of time INR is within the therapeutic range or by the percentage of INR values in the therapeutic range .