Version 1.1. Dennis Mungall. Lansing, Michigan: Therapeutic Technologies; 1993. Available for Microsoft Windows 3.1 with a 386 or higher processor and 4 MB RAM. $999.95.
One of the challenges in the use of heparin or warfarin is arriving at an optimal dose. The literature is replete with various regimens, nomograms, and other devices aimed at helping the clinician decide on an adequate dose of either drug. Even though much is known about the pharmacokinetics and pharmacodynamics of heparin and warfarin, the applicability of this knowledge to the routine clinical situation is less than satisfactory. The developers at Therapeutic Technologies have attempted to improve the situation by offering a computer program that supports the application of pharmacokinetics principles to dosage regimens for heparin and warfarin. In the past decade, several microcomputer programs designed to help the clinician calculate the optimal dosage of anticoagulant agents have been developed. C.O.A.G. Expert represents the second generation of an earlier product, Drug Calc, that has been revised to operate in a Windows format to increase its versatility and scope.
The materials provided for this review included seven diskettes for the program, one diskette labelled "Video Runtime," a manual, and two videotapes. One videotape describes the product and one is a didactic presentation on the pharmacokinetics and pharmacodynamics of anticoagulants and fibrinolytics. The videotapes were reviewed first, and then the software was installed on an IBM-compatible computer with a 486, 50 MHz chip; a VGA monitor; and appropriate hard disk space.
For computer technology and videotapes to be useful, they need to be simple, versatile, and user-friendly. C.O.A.G. Expert does not satisfy these requirements. Unfortunately, perhaps, I viewed the videotapes first. These tapes are of such poor quality that they could have biased an objective appraisal of the diskettes. At various points in the tapes, the narration is interrupted by background noise from what sounds like a convention hall, and on one occasion the listener is startled by an outburst of background laughter. In addition, part of the video presentation consists of a sequence of displays of a computer screen. This sequence contains too much information and cannot be easily seen because of poorly contrasting colors and the annoying and distracting movement of a poorly defined cursor.
The diskettes are about as bad as the videotapes. Even if the user is familiar with Windows-based software, he or she will be immediately overwhelmed with various colors, screens, and icons that seem to reflect the author's obsession with computer technology rather than the message he is trying to convey. There are other problems as well.
Some program data entry is cumbersome, such as that for warfarin in inpatient dosing. In addition, the screens that appear do not match those displayed in the accompanying user manual, promoting some confusion. There also appears to be limited cross-tabulation of data entered in different segments of the program, such as that for outpatient warfarin dosing with inpatient warfarin dosing. In addition, in attempting to use the Help function in the program, an error message (Cannot Open Help File) was encountered even though the program was installed according to directions provided and the installation proceeded without error. The manual is of limited value once the user moves beyond the example provided.
This product, in its current stage of development, cannot be recommended for routine use by the clinician with an average knowledge of computers. For those who are well versed in computer technology and who have both the interest and the time available to learn to use the product, it may represent a worthwhile, or at least an intellectually stimulating, tool. For many, however, discovering the product's usefulness will not be worth the substantial amount of time needed to master the computer "know-how" required to use the program.
The software does have some value. It is a potentially useful tool for characterizing the dose-response profile of individual patients to heparin and warfarin, which have narrow therapeutic indices and considerable potential toxicity if not dosed correctly. In all fairness to the developer, the program itself functioned adequately in the modelling of anticoagulant dose response and dosage recommendation in at least two patients whom the reviewers used to test the program. In these two test patients, estimation of warfarin requirement was within 1 mg of that actually required. Nevertheless, the potential usefulness of the product in clinical situations is poorly served by the product itself. The developers' time would have been better spent on creating a simple, user-friendly software package devoid of distracting colors and screen formats and other unnecessary technological paraphernalia. For most clinicians, the potential utility of the program will not be worth the effort required to use it.
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