From Insight to Implementation: Lessons from a Multi-site Trial of a PDA-based Warfarin Dose Calculator

Clinical decision support (CDS) systems show promise for enhancing patient safety, but they require rigorous evaluation before they can be implemented widely. We developed a software application for use with personal digital assistants (PDAs) that models patient-specific dose responses to help physicians predict steady-state warfarin dosing requirements and steer patients to a therapeutic level of anticoagulation as quickly and safely as possible. We also designed a randomized, controlled multi-site trial to evaluate the effectiveness of the Warfarin Dosing and Communication System (WARFDOCS) in reducing warfarin-related errors. Numerous obstacles delayed implementation of the CDS system and completion of the trial. To better understand the causes that led to the delay, we interviewed key informants at participating hospitals; reviewed study protocols, administrative records, and meeting minutes; and held discussions to review the data and their interpretation. Salient themes were identified by consensus of the research team and these were corroborated by key informants. Four major themes emerged. First, agreement to participate in the trial reflected very different levels of commitment. Sites participating in CDS system evaluations must be managed actively. Second, the enthusiasm of end-users for a CDS system was derived from a complex calculus of perceived benefits and burdens. Unfortunately, the most relevant appeal (that such a system would markedly improve patient safety) could not be made in advance of the trial. Third, research changes everything. Valid research procedures (e.g., informed consent, randomization, and intrusive data collection) may be necessary, but can themselves affect a key outcome of most CDS system evaluations: user uptake. Fourth, strong “center effects” (i.e., the CDS system proved effective at some sites, but not at others) should be expected. If “all politics is local,” then much of patient safety research is localized as well.