With selected patients, the quality of OAT obtained through patient self-management is at least as high as that delivered by specialized physicians at anticoagulation clinics. Weekly management of OAT with long-acting phenprocoumon has to be preferred at anticoagulation clinics or, where possible, through patient self-management.

Summary. Background: Oral anticoagulant therapy (OAT) implies frequent blood checks and dose changes to prevent thromboembolic or hemorrhagic complications. This may interfere with patients' social and working circumstances in addition to the possible stress caused by the condition necessitating this treatment. We studied whether patient selfmanagement could be a way to improve quality of life in these patients. Methods: Within a multicenter randomized study performed by two Dutch anticoagulation clinics, designed to study the effect on treatment quality (time within target range) of different modalities of patient self-management, we looked at the effect of increased patient education (n ¼ 28), self-monitoring of the International Normalized Ratio (INR) (n ¼ 47) and full patient self-management (INR monitoring and dosing of the OAT) (n ¼ 41) on the quality of life of the patients. This was done with the aid of a written questionnaire (32 questions, minimum score ¼ 1, maximum score ¼ 6) at baseline (n ¼ 163), and after 26 weeks (n ¼ 118). We compared the results after 26 weeks with those at baseline, as well as between groups. Results: General treatment satisfaction was already high under routine care (5.11 on a scale of 1-6) and increased further through self-monitoring of the INR (+0.19) and full self-management (+0.32). Distress ()0.44), perceived daily hassles ()0.31) and strain on the social network ()0.21) were reduced through full self-management. Improved patient education was associated with increased distress (+0.33) and perceived daily hassles (+0.23). Comparison at 26 weeks between groups showed similar improvements on these outcomes for self-monitoring and self-management vs. routine care after education.

In The Netherlands, the monitoring of outpatients on oral anticoagulant treatment is conducted, in 95% of the cases, by specialized centers, the so-called "trombosediensten." These centers are recognized by the Ministry of Public Health, Welfare and Sports and must satisfy certain standards and requirements. The centers are united in the "Federatie van Nederlandse Trombosediensten" that provides support in quality assessment and is a board for the negotiations with the government and other authorities. An attempt is made to describe the operation, quality assessment, and the results obtained by these centers by using data from the "Federatie" and one of the centers, in particular. The Dutch system provides a relatively cheap and safe method for treatment with oral anticoagulants, based upon centers where all necessary knowledge is concentrated. The system depends highly upon good communication between referring physician, staff, physicians of the centers, and the patients.

Prothrombin time (PT) is the primary laboratory test for monitoring oral anticoagulant treatment but is influenced by preanalytical conditions and analytical variables, that is, thromboplastin reagents and instrumentation. Standardization and normalization of test results is mandatory. PT results should be transformed to International Normalized Ratio (INR) by calibration of the reagent/instrument system with International Reference standards according to World Health Organization guidelines. However, there is still uncertainty in the INR that is caused in part by calibration errors and in part by interaction between the PT reagent and various factors in the patient's specimen. These problems are highlighted in INR measurements performed with whole blood coagulation monitors. Each center should maintain an appropriate scheme of internal and external quality control for the laboratory INR measurement as well as the individual point-of-care coagulation monitors used by the center and patients for self-testing.