KENNEDY: DUODENAL ULCER SURGERY 785

USE OF A COMPUTER IN DUODENAL ULCER SURGERY BY FRANK KENNEDY

UNIVLRSITY DEPARTMENT OF FURGFRY, WESTERN INFIRMARY, GLAbGOW

THIS paper discusses some of our experience in developing a computer system to aid clinical research in the Department of Surgery at the Western Infirmary, Glasgow. This system, Switch, has been in operation for over 3 years and has been described in more detail elsewhere (Kennedy, Clean, Roy, and _. - - - - Kay, 1968).

The Western Infirmarv is a teachine hosoital and in Scotland this imp1ies.a routine responsibility as a district hospital. There are 670 acute beds and a busy out-patient department with 440,000 attendances per year. The Department of Surgery, with 56 beds, provides part of the routine general surgical service and runs four out-patient sessions per week. Peptic ulcers are particularly prevalent in West Scotland and, because of our special interest, one out-patient session, designated the Peptic Ulcer Clinic, is ex- clusively devoted to this disease. To this clinic arc referred annually about 450 patients from general practitioners or from other hospital consultants for surgical assessment. About half are subsequently admitted to the Department of Surgery for operative treatment and thereafter attend the same clinic for routine follow-up. Although the clinic’s prime responsibilities are assessment and treatment, there arises a wealth of clinical material which is also of considerable research value.

REQUIRElMENTS OF COMPUTER SYSTEM In 1966 a decision was taken to seek a computer

system to handle these clinical data in a routine manner in order to simplify subsequent research evaluation. The system had to meet the following requirements :-

I. It should be capable of handling all clinical information on peptic ulcer patients whether of a routine or a research nature.

2. It should not interfere markedly with the existing clinical management and administrative structure.

3. Flexibility should exist so that the extent and detail of clinical data collected could be altered when required.

4. The system should be readily acceptable and easily used by busy clinicians.

5. The cost should be justifiable within the research budget of a teaching hospital.

6. Accuracy and reliability were essential. When these requirements were studied it became

clear that the solution would have relevance to the more general problem of computer-handling of hospital case records, and in developing the system this broader issue was considered.

Switch is an off-line, batch-processing system using the time-sharing facilities of Glasgow University’s KDFg computer (Fig. I). The system was designed in collaboration with the medical division of English Electric Computers Ltd., and the programming car- ried out in the Department of Surgery over a period of

z years. Eleven special documents were designed to collect information in the out-patient clinic, the wards, the operating theatre, the routine service departments, and the research laboratories.

MAGNETIC

‘?p PATIENT / t FILE

PAPER TAPE

/ n 1

PRINT OUT /@&\\ FLEXOWRITER

I

WARDS OPERATING OUT LABS THEATRE PATIENTS

FIG. flow of information through Switch.

ORGANIZING CLINICAL DATA We had to tackle the problem of converting

routine clinical information, which is often imprecise and poorly organized, into the accurate well-defined form suitable for computer-handling and research analysis. Data are organized on the documents in a combination of fixed format, where each item of information has a fixed position, and variable format, with lists of items of varying lengths. Each data element could be one of four types: numerical, coded, dictionary, or comment.

Much information is already in numerical form and other items can readily be converted, for example, the severity of particular symptoms can be converted by the observer into a coded form with a range 0-3. As an aid to this conversion, item modifiers can be used to indicate, among other things, that an item of data is 75, 30, or 25 per cent reliable in accuracy.

A dictionary of clinical terms is maintained within the computer and by its use the computer can also code certain items. This dictionary is flexible and is routinely updated with new items so that it now contains over 5000 medical words or phrases in categories representing signs, symptoms, operations,

786 BRIT. J. SURG., 1971, Vol. 58, NO. 10, OCTOBER

diagnoses, treatments, and investigations. Table I represents a typical print-out of part of the category for operations. This facility allows the user to collect information in an alphabetical form for computer storage in numerical code.

Table I.--PART OF A DICTIONARY PRINT-OUT

(:AT. 3 GP, y NAME 94 TERM I APPENDICECTOMY TERM 2 LAPAROTOMY AND

APPENDICECTOMY TERM 3 APPENDICECTOMY-

NORMAL APPENDIX

PERITONITIS

TERM 4 APPENDIX TERM 5 APPENDICITIS-

NAME 95 TERM f REPAIR OF LUMBAR HERNIA

N A ME 96 TERM

TERM

TERM

TERM

REPAIR OF

CLOSURE

CLOSURE OF

CLOSURE O F

PERFORATION

PERFORATION

PERFORATION

PERFORATED DUODENAL ULCEK

The final type of data is general comment which is an essential part of a routine case sheet but which is not suitable or valuable for subsequent analysis. At present the system stores and reproduces such information, but it is probable that with development of the system, storage of alphabetical comment will no longer be provided.

DATA PREPARATION From the documents, data are converted into a

form readable by the computer, namely %hole paper tape. This is produced in the hospital computer department by programmatic flexowriters-electric typewriters which, on keying information, produce both typed and paper-tape copies. To minimize error at this stage, documents are punched separately in duplicate, and other automatic features prevent errors of sequence in punching. Our experience suggests that any errors that do arise at this stage are due to the misinterpretation of handwritten medical terms by flexowriter operators.

The computer system is run at least once per week on the KDFg computer to update the patient data file, which now contains the information from 9300 documents on a magnetic tape reel. At the same time a specific program organizes the data from out- patient documents, and prints out a history in sentences on stationery preprinted to be acceptable in routine hospital case records. The computer run is organized so that patients seen at the Peptic Ulcer Clinic have a computer-printed case history inserted in their hospital folders within 24 hours. This routine provision of a print-out avoids the collection of information in duplicate at a busy out-patient clinic and increases user acceptability.

FLEXIBILITY OF SYSTEM In designing the system, consideration was given

to the need for flexibility so that documents could be

altered or new documents produced when required with a minimum of expenditure of time and effort. This flexibiIity was achieved by designing twenty-six general sections of different shapes handling different types of clinical data. Documents were then con- structed using these sections as building blocks and, with added flexibility within these sections, new documents can readily be constructed. Using this method, extra documents have been introduced into the system without alteration to the existing com- puter programs. This has allowed not only altera- tions in the clinical information collected on peptic ulcer patients but also a more general expansion into other clinical areas. The Glasgow Blood- pressure Clinic, meeting in four Glasgow hospitals, has designed its own set of documents from the general sections, and now also uses Switch with the same program suite and dictionary file.

COST-BENEFIT An estimate has been made of the cost. Research

grants from the Nuffield Provincial Hospitals Trust and the Scottish Hospital Endowment Research Trust have allowed the employment of programming and operating staff, the use of technical advice, and the purchase of data-processing equipment. Making no allowance for the considerable time and effort provided by permanent members of the Department of Surgery, but allowing an estimate for the cost of computer rime provided by the University’s Depart- ment of Computing, Switch has cost about E25,ooo to develop. The estimated running costs of the system for the Peptic Ulcer Clinic are Ego00 per annum, which is just under Lzo per new patient per year.

The cost is not high for such a comprehensive system, but it can only be justified when the benefits are fully assessed. Since September, 1970, several extract programs have been run to analyse the data stored on the patient data file. So far these have been of a limited and mainly administrative character in order to aid us in organizing the routine acid tests in the research laboratories and to improve the follow-up of postoperative patients. At present we are deeply involved in assessing the results of an extract and analysis of clinical importance-the evaluation of a trial of varying surgical treatments in duodenal ulcers. A previous preliminary analysis has been carried out by a combination of manual and computer methods and has been reported, partly to this Society (Kennedy, Gillespie, and Kay, 1969) and partly elsewhere (Kennedy, Gillespie, and Kay, 1968). Only when many such analyses have been reported will it be possible to evaluate whether Switch has justified the expenditure of time, effort, and money.

REFERENCES KENNEDY, F., CLEARY, J. J., ROY, A. D., and KAY, A. W.

_ _ GILLESPIE, I. E., and KAY, A. W. (1968), Gut, 9,

_ _ - - - - (1969), Br.3. Surg., 56, 626.

(1968), Lancet, 2, 1230.

734.