Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2014-10-06, 13:17:01 | version 1.33.00
status. NTS staff access this information to check and (if relevant) respond to any mention of thrombotic or bleeding events, adverse effects, changes in concomitant medication and other events. Dose adjustments are provided or, in self-dosing patients, checked and approved or adapted as required. Frequency of testing depends on the level of INR stability, with the appropriate dosing schedule provided by NTS medical staff for PST patients, and determined by PSM patients themselves, supervised by medical staff. Further education, motivational support and––if necessary––reminders are provided on a regular basis. Round-the-clock medical support is also offered to NTS patients. Minor clinical events are regularly self- reported by all patients at the time of the INR measurements. Deaths are required to be pro- actively reported to the Dutch healthcare authorities, and details of serious but non-fatal events may also be requested retrospectively by the authorities. Therefore the NTS captures and retains records of death and serious events that could potentially lead to death which could be related to the therapy, such as hemorrhages or strokes. This has been done in a structured, uniform way since February 2012. While the number of deaths can be reliably captured by the NTS, the actual event or reason for death cannot always be audited reliably. Similarly, serious non-fatal events are not independently audited. Only the verified data regarding number of deaths have therefore been included in this analysis. The therapeutic ranges for INR in anticoagulation therapy with VKAs are individually set by the admitting physician, and follow the Federation of Dutch Thrombosis Services guidelines for INR ranges for different indications [21]. The guidelines specify a low (2.0–3.0) and high (2.5–3.5) intensity anticoagulant range, and recommend an additional 0.5 INR units be considered acceptable in order to avoid low INR values, leading to therapeutic ranges of 2.0–3.5 and 2.5–4.0. In comparison to ‘target range’ used as a standard term internationally, these correspond to INR ranges of 2.0–3.0 and 2.5–3.5. As the TTR is typically used in the Netherlands and the processes of the NTS are laid out accordingly, the TTR was primarily used in the subsequent analysis in this paper. The wider ranges mean that values reported here for TTR and number/proportion of values in therapeutic range are higher than those in many studies in the literature using target ranges 1 INR unit wide [22]. The use of two different point of care coagulometers (CoaguChekÒ XS, Roche Diagnostics, Basel, Switzerland; INRatioÒ 2, Alere Inc., San Diego, USA) with identical protocols within the NTS system allows direct comparison of their impact on patient outcomes. Statistical Analysis All patients entering the NTS from June 2011 and fatal events starting 2012 onwards were included in the analysis. The reason for this start date was that from then onwards the NTS worked with both devices, CoaguChek XS and INRatio2. Monitors were distributed to patients based on device availability within the NTS purchasing system at the time, and with no consideration of patient characteristics except for those in residential care settings (*5%), where the choice was determined by the existing point of care monitors used by the care home. The first 90 days after treatment start were excluded from the observation period to allow for familiarization with the system (consistent with the analytical approach used elsewhere Adv Ther