Building an Ambulatory Clinical Information System in a family practice residency

Journal of Family Practice, Nov, 1989 by Colin P. Kerr

Recent changes in medical technology, the economic incentives of medical practice, and trends in professional liability litigation have all tended toward increased pressure on physicians to be able to measure what they do. Concurrent changes in information technology, particularly in the refinement of the personal computer, have made the development of local information systems not only possible but relatively cheap and easy as well. Residency training programs in family practice need to respond to this altered practice environment by preparing residents to deal with these new realities. In addition, residency programs themselves are under substantial pressure to document their residents' experience to ensure that residents have received adequate exposure to all parts of the recognized curriculum and to assist residents in the application for hospital privileges in this new medicolegal environment.

This paper describes a system developed to address these needs in a family practice residency and implemented over a 2-month period for a net cost of less than $5000. The system is called the Ambulatory Clinical Information System (ACIS) of the Department of Family and Community Medicine of the Milton S. Hershey Medical Center.

The clinical work of the department is currently carried out in a new and separate building, the University Physicians' Center, which houses the ambulatory component of several other specialties as well. The medical center employs mainframe computer technology to implement a centralized computer scheduling system and billing system linking all clinical departments, but neither of these systems provides data of immediate clinical or educational value to physicians. Rather than wait for the existing technology to be supplemented or modified to accommodate the practical information needs of the department, the Department of Family and Community Medicine made the decision to install a separate personal computer-based clinical information system in the Family Practice Center (FPC). Departmental constraints, mainly fiscal, required that the system be flexible, inexpensive, and parsimonious in maintenance and data-entry time.

The personal computer hardware selected was a clone of an IBM PC AT model microcomputer running a 80286 microprocessor at 12 MHz with a 40-megabyte hard disk. This system was purchased by mail order at a cost of $1800, which included a monochrome monitor and dotmatrix printer as well. The software selected was a fourth generation, programmable, relational database called "ZIM,"* with which the author had previous experience. The developer's full version of this program currently costs $2000, but the application described below is available from the author in a compiled run-time version for about $500. This software is also available in multiuser versions. Backup of the system data is carried out using a relatively slow, but inexpensive, 1200-baud modem connection to an independent personal computer in the precepting area of the Family Practice Center using the pcanywhere III remote file transfer program during weekend hours.

The design of the information system is focused strategically on the routine encounter form, which had previously been used solely for fiscal purposes. This form contained much of the important clinical data, namely, patient name and number, physician name, visit date, all diagnoses, all laboratory tests and x-ray examinations ordered, all office laboratory tests done, all immunizations and injectable medications given, and finally all office procedures done in the course of the visit. As the current form already existed in triplicate, it was possible to divert a separate copy solely to the purpose of data entry in the ACIS.

The FPC takes care of a patient population of about 7500 and approximately 20,000 visits per year. Thus, on a daily basis, there are about 40 to 70 encounter forms to be processed. The system has also been designed to capture data from patient registration sheets for new patients, averaging from 0 to 10 such forms per day. The department anticipated that a secretary with no special computer training could type the necessary data in at the computer screen in less than I hour a day; this estimate has proven correct over the first 6 months of operation.

The first step in setting up the ACIS was to transfer by modem the active patient list and corresponding demographic data from the existing practice database on the mainframe system. The file, named PATIENTS, containing the master list of patients and identifying numbers (ID), is the hub of the entire clinical information system. The properties of the relational database allow the database design to conform to the logical sequence of clinical operations in the center (Figure 1).

Figure I illustrates the relationships between the major classes of data that are currently being tracked in the ACIS. The primary block of data is the master patient list (PATIENTS). This data set is further characterized by several supporting files for specific data subsets, such as extended demographic data (for research purposes), household and family sets, initial clinical data abstracts INTAKES), and health maintenance flow chart data (HMFS).