Patients taking warfarin require frequent blood tests to maintain a safe and effective level of anticoagulation. A recent study evaluated the time and expense spent by patients to travel to and from anticoagulation clinics for evaluation of international normalized ratio (INR) blood test results.

A multinational investigation looked at the cost incurred by 381 patients from six countries. Cost figures were calculated (in Euros) for patients in Austria, France, Portugal, Spain, Sweden and the UK. Patients from the United States were not included in the study.

The goal of this study was to determine both the travel and time costs for a patient to visit an anticoagulation clinic. Because patients who self-test could reduce the total number of visits to clinics, they were excluded from this study.¹

Travel Costs
Transportation costs included the distance covered and time spent during travel. An average cost per kilometer was derived and applied for the six countries studied. Additional transportation costs included parking fees, public transportation, taxi fares, and mobility service costs.¹

Time Costs
Time costs were incurred both by patients who were required to leave work and who sacrificed leisure time to visit a clinic. Lost work time costs were estimated based on net wage per hour rates. Leisure time costs were calculated at 35% of the local gross average wage per hour. Time costs were also considered for companions of patients needing assistance, and were included in the cost analysis.¹

Costs converted from 2003 Euros to 2008 U.S. Dollars [1 U.S. Dollar = 1.59 Euro]
This international cost analysis is one of the largest published patient time and cost studies. Limitations to this study include variation in healthcare delivery and service, socio-economic factors, cultural variables, and economic issues such as employment rates and labor wages.¹

The average cost per clinic visit in 2003 Euros across the six countries was 17.11, which is $27.20 in 2008 U.S. dollars. The authors suggest that the high costs in Portugal and Spain resulted from increased time spent traveling and in the clinic itself, as well as higher companion costs. France’s costs were low due to lower patient time costs.¹ The cost analysis of patients in the United States was not included in the study. However, travel and time costs would similarly affect patients in the United States who travel to anticoagulation clinics.

Although patient self-testing was excluded as a model of care from this study, it plays an important role in improving anticoagulation control. The average number of clinic visits for patients in the UK was reported to be only between 8-12 per year.¹  Weekly home testing is proven to increase time in range by 35% over monthly testing, allowing for better control of warfarin dosing,² and could perhaps contribute to decreased costs associated with lost wages and travel time.

The authors of this study concluded that, while costs varied by country and healthcare delivery, costs overall were considerable for patients visiting anticoagulation clinics.¹ By decreasing patient travel and time costs, home INR monitoring could improve the cost-effectiveness of warfarin patient management.