The Information System Deployed
We developed a system for implementing clinical practice guidelines designed to translate hypertension research findings into practice in primary care clinics. The approach provides automated decision support for primary care clinicians. The decision support system ATHENA DSS was designed as a platform-independent system for integration with an existing electronic medical record (EMR) system. ATHENA DSS uses a guideline interpreter to combine patient information from the EMR with knowledge of hypertension to generate patient-specific recommendations, explanations, and evidence-based education, which are then delivered to clinicians in a pop-up window at the time of outpatient primary care clinic visits.7,24
ATHENA DSS was constructed using the EON architecture developed at Stanford Medical Informatics for guideline-based decision support systems.25
shows the basic system architecture. It includes a knowledge base (KB) that models hypertension knowledge, a guideline interpreter, a temporal database mediator, and a custom graphical user interface. ATHENA DSS, developed in Protégé, separates the KB from the interpreter rules and the patient database, so that clinician-managers can easily browse and update the KB.
Our aim was to integrate ATHENA DSS into the primary care clinics at three VA medical centers—VA Palo Alto Health Care System (VAPAHCS), San Francisco VA Medical Center, and Durham VA Medical Center—to implement national guidelines for the treatment of hypertension. We are evaluating the impact of this guideline implementation on patient care in a randomized, controlled trial (RCT) with patients' blood pressure control and guideline–drug concordance as the primary outcome measures (results not yet available). We implemented the system first at VAPAHCS for a limited number of clinicians who would not be enrolled in the study. After we had gained experience with the implementation process, we installed the system at San Francisco and Durham, starting with the physician-investigators and later moving to a larger group of primary care clinicians for the clinical trial.
ATHENA DSS is a platform-independent system designed for integration with legacy patient data systems.26
VAPAHCS uses the national Department of Veterans Affairs' medical record system27
VistA (Veterans Health Information Systems and Technology Architecture) (largely based on M, formerly known as the Massachusetts General Hospital Utility Multiprogramming System or MUMPS), and its user interface, Computerized Patient Record System–Graphical User Interface (CPRS-GUI).
An overall organizational requirement for the initial deployment at VAPAHCS was that the system be consistent with the VAPAHCS's goals for clinical practice guideline implementation and that it enhance clinician acceptance of guideline-based recommendations. Our design requirements included achievement of VAPAHCS's administrative goals, acceptability to clinician-users with simple user interface, and consistency with the RCT protocol. As a result, our integration objectives for ATHENA DSS were as follows:
Integrate Smoothly into Individual Clinician's Workflow
- For recommendations to appear at the time of clinical decision making, without requiring further action by the clinician, advisories must appear to the clinician in the CPRS-GUI coversheet as a pop-up window when an appropriate patient record is accessed.
- Generation of the recommendations using the patient data must not require that the clinician retype data known to the system.
- Entry of updated information at the option of the clinician must return a nearly instantaneous update of recommendations.
- The system must not slow down workstation performance in the clinics.
- Users must be able to bypass the pop-up window easily if they do not want to use it.
- The system must run on the existing operating system.
Meet Additional Institutional Goals
- For patient privacy protection, the entire system must operate on the VA Intranet behind the VA firewall and present advisories only to users who have logged on to the CPRS.
- The advisories must appear only on the computer screens in the primary care clinics and not in areas of the hospital in which hypertension management is typically different from that in primary care clinics, for example, in the intensive care units and acute medical units.
- The advisories must appear only for primary care clinicians enrolled by the developers and not for other clinicians viewing the patients' records.
- The system must be available at all primary care clinics of VAPAHCS, including those more than 100 miles from the main site.
- The recommendations must be available on the day of a scheduled primary care clinic visit for a patient with a diagnosis of hypertension and on the working day preceding each visit so that clinicians who do visit planning can see the advisory at the time that they preview their clinic charts.
Maintain the System Accuracy over Time
- The system must send alerts to the developers for drug names that do not match a drug already recognized by the system (for example, when a new drug is added to the formulary).
- Updating the knowledge base must be possible without reinstallation on the clinic computers.
- The system must monitor each clinic computer for activity.
- The system must allow clinician-users to provide free-text feedback that can be monitored for early identification of problems.
Allow for a Clinical Trial Randomized by Clinicians
- The system must permit display of two different versions of a pop-up window to designated clinicians to allow for a control group and an intervention group in the RCT.
- The system must allow clinician-users to provide feedback on their deviations from the system's recommendations.
- The system must capture data for evaluation, including its recommendations, and clinician usage data.
To accomplish these goals, we involved representatives of the organization in the technical design in an iterative process, selecting technical features to enhance acceptability of the system to clinicians and administrators: a sociotechnical approach.
We included three VA medical centers: VAPAHCS, San Francisco VA Medical Center, and Durham VA Medical Center. VAPAHCS, the initial site, is a large integrated health care system in mid-coastal and central California, spanning more than 13,000 square miles, with a tertiary care hospital at the main campus and a network of sites with subacute units, long-term care, and outpatient clinics. We included clinic sites of VAPAHCS located at Palo Alto (PAD), Menlo Park (MPD), San Jose (SJC), Monterey (MON), Capitola (CAP), Livermore (LD), Stockton (STC), and Modesto (MOD). Driving time from the main campus at Palo Alto to the outer sites is greater than two hours even in optimal traffic conditions. Primary care clinicians with drug prescribing privileges include approximately 55 attending physicians, 40 resident physicians, and seven nurse practitioners and physician assistants. Clinic sites include many shared-use areas in which primary care clinicians and specialists use the same computers. In the primary care areas of VAPAHCS, there were 146 computers from various manufacturers, running either Microsoft Windows NT or Windows 2000. All are networked to the central VistA computers located in Palo Alto.
San Francisco and Durham VA Medical Centers' primary care clinics included in the study are both located in a single building, with a smaller number of computers (approximately 25 at each site). Clinicians at all sites possess a wide range of computer experience, including some who are adept and others who are beginners.