This program is designed for a urologist as a Decision Support System to facilitate ... the input that will affect the diagnosis and treatment decisions of the ...
Journal of Medical Systems, Vol. 23, No. 5, 1999
A Pascal-Based Decision Support System Model for Diagnosis and Treatment Processes in Urology Serdar Miildur1 and Inan Guler1
This program is designed for a urologist as a Decision Support System to facilitate the pre-diagnosis and identify the definite diagnosis as quickly as possible with the help of symptoms and physical examination by taking into consideration all the possible diseases with cross-questioning. The aim is to enable the physician to display on the monitor all the possible diseases causing the arising symptoms by entering the symptoms and the physician's observations into the database with "yes" or "no" type answers. KEY WORDS: decision support system; pre-diagnosis; physician's observations; cross-questioning.
INTRODUCTION In medical practices, providing every kind of service in proper purposes and cost-effective ways is an important requirement for both human life and effective usage of the resources. It is true that the most important factor that leads us to the correct decision in the application phase is information. Human beings can complete collecting and processing data, leading to information, by mental observation. These processes of observation may differ from time to time according to personality, education level, experience, and psychological conditions. In light of these facts, usage of auxiliary systems that will support reaching the correct decision will increase the effectiveness to obtain the targeted results.(1) Information that is given by a patient from the beginning phase will become the input that will affect the diagnosis and treatment decisions of the specialist.(2) It is as important for a patient to report every change she/he has noticed in his/ her condition in detail as for a specialist to cross-examine every symptom that is necessary for the specialist's diagnosis. If a physician is able to guide a patient with proper questions and records every symptom, even those that are ignored by the patient, as "yes" or "no" answers, she/he may increase the effectiveness in the diagnosis and treatment phase. For the reasons mentioned above, a Pascal program 1
Electronics & Computer Education Department, Faculty of Technical Education, Gazi University, 06500 Teknikokullar, Ankara-Turkey.
357 0148-5598/99/1000-0357$16.00/0 © 1999 Plenum Publishing Corporation
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was prepared and successfully applied to the real hospital environment. This program helps a physician to cross-examine both the patient's data and the symptoms that are found by the physician; leading the physician to a possible diagnosis and providing the questions regarding the possible illness. The following stages must be followed in order to reach a definite diagnostic decision.
SYMPTOMS A disease causes some disorders in the normal functioning of an organism as well as certain problems in someone's life. A patient goes to a physician with these symptoms. These data constitute the first step on the way to diagnosis. However, they are not sufficient for definite diagnosis. PHYSICAL SYMPTOMS The physician goes on with the examination by carrying out some physical experiments on the patient to determine if it is one of the suspected diseases; for example, by measuring the patient's fever, examining the relevant organs, and measuring the patient's reaction to some physical forces. LABORATORY INSPECTIONS Likely diseases are considered by the physician, however, for definite diagnosis, the results of the laboratory tests are necessary. Among laboratory tests the physician selects the ones for the most likely diseases and those tests are carried out. The results of the tests yield the definite diagnosis and the physician can then apply the treatment accordingly. In fact, what is done while the physician carries out the examination is the application of physician's entire experience to the patient. The physician processes the data she/he already knows through an algorithm and reaches a solution. This process can be carried out partially by the computer. Once all the diseases are stored into the database, the relevant disease can be selected from the database by the answers to appropriate questions. For this, the database must be formed and access to it must be made possible with those questions. METHODOLOGY The number of symptoms, which are results of diseases, may be one or more than one for each disease. Similarly, the same symptom may arise in more than one disease. In other words, the relationship between symptoms and diseases is vast. As a result, one symptom can lead the algorithm to more than one disease;
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Diagnosis and Treatment Processes in Urology Table I. Relationship Between Symptom Code and Disease Codes Symptom Code
1 2 3 4 5 6
7 8 9
Symptom Name Lumbago Headache Hypertension Kidney ache Urine inflammation Palpable kidney Lack of appetite Hematury Nausea
Disease Codes Related to Symptoms
1 1,5,9,22 1,2,5,9 3,4,5,11,12,21,22,23,28,31 3,10,11,12,13,14,15,16,17,18,19,20,22,24,25,28,29,30,31 3,4,5,6,7,8,11,14,28,29,31
21 5,10,19,24,26,28,30,31 5,21
however, what is distinctive is how many of the symptoms for the disease are present simultaneously. Then, the algorithm can focus on a group of diseases eliminated from the others. For definite diagnosis it should be kept in mind that there is a need for the results of laboratory tests beyond the symptoms and physical examinations. In this program the similarities between the algorithm and the physician's thinking while trying to get to the definite diagnosis, are both implemented. For this purpose two databases are used. The databases are related to each other by the disease numbers. First, symptoms and the results of physical examinations are extracted and a symptom database is formed, as shown at Table I. As stated above, a symptom may belong to numerous diseases. That is why symptoms are stored into the database in the following manner: (a) A code column was allocated for each symptom, (b) A name column was allocated for each symptom, (c) A field was created for each symptom to store which diseases caused the symptom. The codes of the diseases causing the symptom are stored into this field. In the disease database, as shown in Table II (a) a code column was allocated for each disease; (b) a name column was allocated for each disease; (d) A field array was created for each disease to store what the laboratory test results must be for the definite diagnosis. The data entry into the symptom and disease databases is made by making use of the program. The data entry is made from the symptom data entry menu Table II. Relationship Between Disease Code and Symptom Codes Disease Code
Disease Name
1 2 3 4 5 6 7 8 9
Renal aplazi Unileteral renal hipoplazi Solit cyst of kidney Unilateral mutikistik kidney Polycyst kidney Modulary sponge kidney Lump kidney Accessory kidney Arteriovenouz fistula
Symptoms Related to Disease Codes 1,2,3
3 4,5,6
4,6 2,3,4,6,8,9
6 6 6 2,3,10
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by selecting the appropriate option. The table is filled in with the symptom code, symptom name, and the codes of the diseases causing the symptom to arise. In the program, a maximum of 200 disease codes can be entered for a symptom. Filling out this field can be terminated by entering 0 (zero) if the number of the disease is less than 200. The data entry for a disease is made from the main menu. The table is filled in with the disease code, disease name, code of the symptoms of the disease, and the laboratory test results necessary for the definite diagnosis. Table I and Table II show examples from the databases. As it can be seen from these tables the disease codes to which symptoms belong enable the relationship with the disease database. Identifying the Diagnosis Each record in the symptoms database has great importance in diagnosis. The content of each entry plays an important role in reducing a great number of diseases down to a limited group. These processes are realized in the following way. Figure 1 depicts the work flow of the diagnosing process. In the first phase, symptoms narrated by the patient are recorded; then likely diseases which have those symptoms are listed. In the second phase, the physician checks the other symptoms, which are not expressed clearly by the patient of a specific disease, to
Fig. 1. Work flow of diagnosis process with cross-questioning.
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determine the most precise decision. The first entry in the symptoms database is read and the availability of each symptom is checked by an if-clause. If a symptom is available, then the disease codes which contain that symptom are copied into a two-dimensional array from the field storing diseases. The first dimension stores the disease code and the second dimension stores the number of symptoms belonging to that disease which are expressed by the patient and observed by the physician. This process is applied to all symptom entries. As the first dimension of each entry refers to the disease code, by using this code we can access that disease in the disease database to find out the total number of symptoms of the disease. When this number is divided by the number in the second dimension of the array, we have a percentage for the pre-diagnosis. After the results of laboratory tests are obtained that information will be useful for the accurate diagnosis. As each element of the array is a disease code, if the process is applied to all elements of the array, we can roughly determine which diseases and in what proportions of the symptoms the patient may have. It ought to be kept in mind that in all those pre-diagnosis operations, the accurate diagnosis will be achieved by the results of laboratory tests. DISCUSSION AND CONCLUSION In this program, queries have been carried out on symptom entries and disease entries related to these symptoms. In this program what is aimed at, as stated previously, is not to remove the physician's function but to help the physician. Since the number of all diseases and their symptoms is too large to keep in mind, they are kept in a database. Thus, as long as the data are entered correctly into the database, it is possible to obtain the true results without error. The algorithm applied may not yield true results in symptoms which need the physician's interpretation. To cope with this, the questions for the symptoms must be increased. Due to the fact that both databases are with open architecture, i.e., open for further developments, the number of diseases can be increased. If the code is written in an object-oriented programing language besides a textbased programing language, it will be more visual. The program can also be tailored to branches other than urology. REFERENCES 1. 2.
William, T.F., Goossen, P., Epping, J.M.M., Hasman, A., Dassen, W.N., and van den Heuvel, W.J.A., Can we solve current problems with nursing information systems. Comp. Meths. Programs Biomed. 54:85-91, 1997. Fox, J., Johns, N., Lyons, C, Rahmanzadeh, A., Thomson, R., and Wilson, W., PROforma: A general technology for clinical decision support systems. Comp. Meths. Progr. Biomed. 54:59-67, 1997.
