two decades, however, their use in medical practice remains limited. This may be due ... the flow chart not relevant to a particular case, (2) hide details not of immediate .... Centers," Meth Inform Med 15:168-173, 1976. 10. Wirtschafter D et al., ...
A Clinical Algorithm Processor: Enabling Flow Charts to Organize a Variety of Physician Tasks Thomas W. Abendroth, MD Robert A. Greenes, MD, PhD Harvard Medical School, Decision Systems Group Brigham and Women's Hospital, Department of Radiology Harvard School of Public Health, Department of Biostatistics
Boston, MA Historical perspective
quality assurance (where significant deviations from the suggested protocol could be flagged both at the time of entry, and for later review) order entry (allowing rapid selection from a list of * diagnostic and therapeutic actions appropriate in managing each particular clinical problem) * physician reminders (using the algorithm to define the next action which should be performed, and when) By performing tasks such as these, computerized algorithms might both save physician time and promote compliance with the recommended protocols. *
Clinical algorithms (flow charts) are a frequent means of portraying the branching structure of diagnostic and therapeutic protocols. Their current popularity in the medical literature [1-5] attests both to their familiarity among health care providers, and to the potential for organizing extensive libraries of algorithms from existing sources. Despite the increasing visibility of flow charts over the past two decades, however, their use in medical practice remains limited. This may be due in large part to restrictions imposed by the traditional static (printed) presentation of algorithms [6]. Since these limitations can be overcome with dynamic computer presentation, we envision several potential roles for flow chart protocols.
Project goals
Roles for clinical algorithms
Recognizing the potential for algorithms to organize medical knowledge in a problem-specific manner, we have developed and are enhancing a computer tool for the creation, editing, and display of algorithms. The Clinical Algorithm Processor (CAP) is an ongoing project whose purpose is twofold: (1) to facilitate the development and dissemination of diagnostic and therapeutic protocols expressed as flow charts and (2) to explore the potential of flow charts for organizing a wide variety of physician activities, ranging from medical record entry to generating patient correspondence. After receiving feedback on several working prototypes of the physician-computer interface for CAP, we have designed a standalone functional system and are implementing this design in stages. CAP is written in object-oriented Pascal for the Apple Macintosh, which was chosen for its ease of developing window-based graphical applications. The conceptual design of CAP would be portable to most machines with high resolution graphics and a pointing device.
In addition to educating health care personnel about emerging standards of care, algorithms can guide the information collection and therapeutic action necessary to achieve these standards [7-10]. They provide a framework for both concurrent (during the patient encounter) and retrospective quality assurance [8]. Berwick [11] suggests that algorithms might help to reduce unjustified variability of medical practice within large health care organizations, providing both medical and financial benefits. Algorithms might also serve as an entry point for context-sensitive decision support [6], in training medical students [7], and for presenting insurance reimbursement protocols.
Organizing medical information Clinical algorithms are one tool for managing the overwhelming volume of medical information. By targeting a specific diagnostic or therapeutic problem, each algorithm defines a relatively narrow focus around which relevant information and action can be organized. By concentrating attention on a small subset of the available information (be it textbook knowledge or patient medical record data), algorithms promote a planned and consistent approach to problem management. Algorithms can organize a myriad of details into the context of specific problem solving strategies. If the logic of these strategies were coupled to the electronic medical record, it could be used for a variety of purposes:
Program design To overcome the rigidity and incompleteness traditionally associated with printed flow charts, CAP provides the user a variety of methods for rapidly accessing relevant information contained within the protocol: The static flow chart is replaced by a dynamic display which allows the user to: (1) prune away portions of the flow chart not relevant to a particular case, (2) hide details not of immediate concern, and (3) examine in greater depth portions of the flow chart which are of current interest.
automatic generation of patient correspondence (the contents of which would depend upon the patient's position in the algorithm)
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A variety of browsing and zooming techniques allow the user to navigate through the algorithm while maintaining context and orientation. For example, the user can selectively expand the algorithm from any point onward, or collapse selected steps in the algorithm into an abbreviated format.
purposes: to become familiar with recommended
protocols, and to apply these protocols to specific
patients. The physicians' needs in these two situations are very different, and this difference must be reflected in the user interface and functionality provided by the algorithm.
Each step in the flow chart provides instant access to further documentation which explains and/or justifies that step in the protocol. This documentation is presented in the form of knowledge frames, each of which encapsulates one chunk of information relevant to the protocol. Currently, the content of knowledge frames is restricted to text. In the future, pictures and tables will be supported as well, and knowledge frames of all three formats will be interconnected by hypermedia links.
Demonstration This demonstration will present techniques which allow the user to dynamically expand and collapse the flow chart, and to access the documentation supporting each step in the algorithm. The authoring process will be shown, including the construction of flow charts and the creation of hypermedia links. Discussion will focus on the multiple ways in which these techniques can be applied to a variety of physician tasks.
In addition to their hypermedia connections with the flow chart, all knowledge frames are accessible by separate indexing methods. Thus, a user need not consult the flow chart itself to review one particular piece of information presented in the protocol.
Acknowledgments This work was partially supported by Grants LM03707 and LM04572 and Contract LM63523 fom the National Library of Medicine, DHHS. The authors wish to thank Richard Rathe, Carmi Margolis, and Larry Gottlieb for their contributions to the CAP project.
Other areas of investigation We are actively investigating a variety of issues central to the design of computerized algorithms which are more flexible than their printed counterparts. These conceptual and implementation considerations include the following:
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Different purposes for consulting algorithms. Physicians consult algorithms for two very different
References 1. Editors of Patient Care Magazine: Patient Care FlowChart Manual, ed 3. Oradell, NJ, Medical Economics Co Inc, 1982.
How to handle data collected in an order dfferentfrom that expected by the algorithm. In certain cases, premature collection of data items (such as definitive test results) obviates the need for actions which normally would be recommended (such as preliminary testing). Though there is no general method for the computer to recognize these cases, the algorithm author could specify such situations.
2. Cardiology Emergency Decisions, Emergency Decisions, MRI Decisions. All published by PW Communications, Inc, Secaucus, New Jersey.
3. Eisenberg RI and Amberg JR (eds), Critical Diagnostic Pathways in h. Philadelphia, JB Lippincott Co, oaladk: anllgQhmiia 1981.
Allowing data to be entered in clusters. There are often reasons to relax the rigid lock-step flow of data collection typically depicted in printed algorithms. For example, common practice is to conduct a history and physical at the start of a patient workup, regardless of when the information derived from these examinations is used in an algorithm. To reflect this practice, computerized algorithms must allow the (optional) entry of all relevant history and physical findings at the beginning, and adjust the flow chart accordingly.
4. McNeil BJ and Abrams HL (eds), Brihm and Women's Hosil Handbook of D iag~fic Imaging. Boston, Little Brown & Co, 1986. 5. Eisman B and Wotkyns RS, Surgical Decision Making. Philadelphia, WB Saunders Co, 1978. 6. Abendroth TA, Greenes RA, Joyce EA, "Investigations in the Use of Clinical Algorithms to Organize Medical Knowledge." Proceedings of the Twelfth Annual Symposium on Computer Applications in Medical Care, Washington, D.C., November 6-9, 1988. New York, IERE Computer Society Press, 1988.
Various selection methods used at branch points in the algorithm. The algorithm author should be free to define a variety of methods for determining the appropriate path to be taken from each branch point in the flow chart. These methods range from simple yes/no decisions entered by the algorithm user, to evaluation of criteria tables which incorporate history, physical, and laboratory data from the patient record. Scripting language for manipulating patient-specific data. It is sometimes useful for algorithms to perform calculations based on patient-specific data, such as determining dosing information based on patient weight and renal function. In order to provide such calculations, the algorithm author must have a language to represent and manipulate items in the patient's medical record.
7. Margolis CZ,"Uses of Clinical Algorithms," JAMA 249:627-632, 1983.
8. Komaroff AL et al., "Protocols and 'Auditable' Checklists in Ambulatory Medical Care," QRB 5:22-26, 1979. 9. Mesel E et al.,"Clinical Algorithms for Cancer Chemotherapy Systems for Community-BasedConsultant-Extenders and Oncology Centers," Meth Inform Med 15:168-173, 1976.
10. Wirtschafter D et al., "A Consultant-Extender System for Breast
Cancer Adjuvant Chemotherapy," Ann Int Med 90:396-401, 1979.
11. Berwick DM, "The Society for Medical Decision Making: The Right Place at the Right Time," Med Decis Making 8:77-80, 1988.
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