Biomedical subjects
Publications and source records attributed to P Degoulet.
This paper presents the architecture of the Information System of HELIOS, a medical Software Engineering Environment. It is an object oriented framework for the development of medical applications which puts particular emphasis on tools and techniques favouring reuse of previous work and enhancing collaboration between developers.
Modularity, distribution and integration are current trends in Software Engineering. To reach these goals HELIOS, a distributive Software Engineering Environment dedicated to the medical field, has been conceived and a prototype implemented. This environment is made by the collaboration of several, well encapsulated Software Components. This paper presents the architecture retained to allow communication between the different components and focus on the implementation details of the Software Bus, the communication and integration vector of the currently running prototype.
An integrated approach, progressively implemented in the ARTEMIS system since 1975, is described for the computerized management of hypertensive patients. From a medical point of view, computerized programs can be used to memorize patients' individual records and profiles, to facilitate patient management and follow-up, to store medical knowledge about hypertension and to provide facilities for decision making at the level either of the individual patient or of the population followed up. From a technical point of view, the methodology used integrates data and knowledge management facilities into the same software. Five hypertension clinics are presently using the system in France and more than 22,000 records have been registered. Answer rates to 12 mandatory questions regarding past history and examination at first visit were superior to 95% in 19,601 records created between January 1976 and December 1987. Patient database interrogation can be used to evaluate the sensitivity and specificity of various signs and symptoms for the diagnosis of secondary hypertension, and to predict, for each patient, his/her cardiovascular risk, the risk of drop-out, the risk of insufficient blood pressure control and the probable blood pressure level. It also serves to test the content and validity of the associated expert system which is progressively built up. A prospective evaluation of the performance of the expert system on 80 cases of hypertension showed overall agreement between the specialists and the expert system ranging from 58 to 91% depending on the decision.(ABSTRACT TRUNCATED AT 250 WORDS)
In order to evaluate possible correlations between blood pressure levels and sleep quality, 7,901 workers of both sexes living in Paris area have been the subject of a survey during their annual examination performed by workside physicians. The enquiry included questions related to sleep quantity and quality, sleeping pills consumption, awakenings, nightmares, snoring, way of life and working conditions. The information concerning these parameters was available for 7,542 people. Among them, 6,551 (86.9%) did not suffer from high blood pressure (HBP) (blood pressure less than 160/95 mmHg), 618 (8.2%) presented a high blood pressure but were not treated, 371 (4.9%) received a treatment against HBP. The average sleep duration is about 7.4 h (S.D. = 1.0) for men and about 7.6 h (S.D. = 1.0) for women (less than 0.001). It is significatively and negatively correlated with the systolic blood pressure level (SBP) (less than 0.001) and the diastolic blood pressure level (DBP) (less than 0.001). The frequency of patients complaining of nightly awakening and of snoring significatively increase with SBP (p less than 0.05) and DBP (p less than 0.001). The observed association between DBP (but not SBP) and sleep duration and nightly awakening remains significant in multivariate analysis including age, sex, tobacco smoking, alcohol and coffee consumption, use of sleeping pills and hypotensive treatment, as well as the negative correlation between SBP and nightmare frequency. The correlation between SBP or SBP and snoring was no more significant. In conclusion, a significant correlation has been found between the blood pressure levels and the sleep quality whose clinical consequences remain to be explored.(ABSTRACT TRUNCATED AT 250 WORDS)
The health benefits of hypertension treatment at the community level depend both of the quality of the blood pressure control obtained for each patient treated individually and of the percentage of the hypertensive patients actually aware, treated and controlled for hypertension in the entire population. The data collected in 1987 in a group of 7,901 subjects working in medium-sized companies of the Paris region were analysed, and compared with those obtained in a very comparable population in 1979-80. Among patients aware of their disease, the percentage of treated patients was higher in 1987 than in 1979, 55 p. 100 and 46 p. 100 respectively in men (p less than 0.001); 70 p. 100 in 87, 59 p. 100 in 79 for women (p less than 0.01). Hypertension was treated and controlled in 27 p. 100 of the men (16 p. 100 in 1979), and 42 p. 100 of women (27 p. 100 in 1979). Awareness was significantly lower among migrant workers than among european personnel (p less than 0.001). The lower the educational level, the lower the compliance with antihypertensive treatment, ranging from 99 p. 100 for the highest educational level, to 82 p. 100 among low educated subjects (p less than 0.001). The hospitalization rate did not differ according to sociocultural factors. Hypertension was detected by the worksite physician in 51 p. 100 of the male hypertensive patients. He was the sole physician who examined 17 p. 100 of the patients in the previous year. These results suggest a moderate improvement in hypertension detection and control. However, development of intervention strategies and their evaluation are clearly needed.
Forty patients with hypereosinophilic syndrome (HES), defined according to the criteria established by Chusid et al., were studied retrospectively in order to determine the prognostic factors in this heterogeneous disease. A myeloproliferative syndrome (MPS) was diagnosed 17 times when splenomegaly and/or a greater than 5 times the normal vitamin B12, level existed. Cutaneous-visceral involvement was almost always present (95%), but could appear after several years of evolution. Twenty-three patients had cardiac involvement, determined by clinical, radiological, electrocardiographic and echocardiographic examinations; 12 of these had endomyocardiac fibrosis. The overall survival rate was 80% at 5 years and 42% at 10 and 15 years. Among the factors evaluated that are capable of influencing this survival, 5 were found to impair the prognosis; presence of an MPS; non-response of the hypereosinophilia to corticoids; existence of a cardiopathy; being male; and an elevated maximum eosinophilia; the last two factors were significantly associated with the cardiopathy. Because hematological or cardiac anomalies are not always present at the time of the first examination, HES patients require very close surveillance.
By using information prospectively collected in the computerized ARTEMIS databank, the long-term metabolic consequences of spironolactone, hydrochlorothiazide-amiloride combination and cyclothiazide-triamterene combination were evaluated in 100 patients for each group matched according to sex, age and blood pressure (BP). Spironolactone was prescribed at a mean dose of 98 mg, hydrochlorothiazide at 36 mg and cyclothiazide at 2 mg, during a mean follow-up of 20 months. Compared with the pretherapeutic values, BP decreased equally in both treatment groups (18/9 mm Hg on average). Creatinine increased significantly in the 3 groups (9, 8, 14 mumol/liter, p less than 0.001) as did uric acid (18, 31, 42 mumol, p less than 0.001). Plasma potassium increased with spironolactone (0.7 mmol/liter, p less than 0.001) and remained stable with the combinations of the thiazide-potassium-sparing agents. For the 3 groups, the slight and nonsignificant variations of fasting blood glucose and cholesterol were mainly the results of a phenomenon of regression to the mean. However, when both groups of thiazide-treated patients were considered, the reduction of plasma potassium was accompanied by a slight increase in glucose (0.1 mmol/liter) and cholesterol levels (0.2 mmol/liter) compared with when kalemia decreased (-0.1 and -0.1 mmol/liter, respectively, p less than 0.05 and p less than 0.05). It is concluded that in a clinical daily practice of a hypertension clinic low doses of spironolactone or of thiazides combined with potassium-sparing agents reduced BP without alteration in lipid or carbohydrate metabolism on long-term follow-up.
Alcohol consumption and glycosuria were found to be associated (p less than 0.001) in a population of 6571 salaried employees who underwent a systematic examination. The prevalence of glycosuria was found to range from 1.3% among 2609 non-drinkers to 5% among 816 heavy drinkers (six glasses or more of alcoholic beverage daily). This association was still significant after adjustment for age, sex and body mass index. Similarly, a positive association was observed between fasting glycemia and alcoholic intake in a subgroup of 998 subjects when such a result was available (p less than 0.05).
The computerized medical specialized records covering the follow-up of hypertension (ARTEMIS), diabetes (MELLITEE), chronic renal failure and the minimum medical record of Nephrology (THESEE) using the temporal database management system LIED, have been developed in several units of University Hospitals. The authors show that these computerized records are usable in a Nephrology Unit in a General Hospital.
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Six thousand six hundred thirty two subjects, employed in 420 small and medium-sized companies in the Paris region were examined in a cross-sectional study. Their alcohol consumption, as obtained by interview was found to be higher among males than among females, among workers than among managers, executives, and clerks. Alcohol consumption was positively associated with age, body mass index, coffee and cigarette consumption, occupational exposure to noise and working nights or alternating shifts. A positive, continuous, relationship was observed, for men and women, between alcohol intake and both systolic and diastolic blood pressure. This association was highly significant in the multivariate analysis (multiple linear regression) where alcohol intake, following age and body mass index, was the third predictive factor of blood pressure level in the stepwise regression. The positive association between alcohol consumption and prevalence of arterial hypertension was aggravated by the poor control of hypertension which was found among drinkers. Awareness of hypertension, compliance with an antihypertensive treatment and its efficacy, were negatively associated with alcohol intake. The findings stress the importance of alcohol consumption which was found to be a major risk factor for arterial hypertension and noncompliance with antihypertensive treatment in this population.
The capacity of chronically hemodialyzed patients to metabolize acetate during conventional hemodialysis was evaluated using a retrospective study in 219 patients dialyzed for up to ten years under similar dialysis conditions. For each patient, and using all available data, a regression line relating the changes of plasma total CO2 during dialysis as a function of the pre-dialysis value was calculated. The intercept of this function indicates the plasma concentration where the losses of bicarbonate in the dialysate is matched by the generation of bicarbonate arising from the metabolism of acetate. This value therefore represents an individual index of the capacity of each patient to metabolize acetate. A value for this index smaller than 18.0 mM was considered abnormal. It was shown that around 10% of chronically hemodialyzed patients are clearly unable to metabolize acetate optimally. This defect is not related to the duration of dialysis, body weight or quality of hemodialysis treatments but is strongly related to sex, 19 of the 22 "acetate intolerant" patients being women. In a prospective study, all the 60 patients of the same population undergoing active dialysis were studied, and this index identified 12 abnormal (11 women, 1 man) patients and 48 normal patients. Plasma acetate measured at the end their dialysis treatments were significantly higher in abnormal than in normal patients. It is concluded: that this index is useful to identify the patients unable to metabolize acetate optimally; that only around 10% of hemodialyzed patients present a severe problem when dialyzed against acetate and should be dialyzed against bicarbonate; that dialysis against acetate does not fully correct the metabolic acidosis even in "normal" patients.
Results of antihypertensive treatment were analyzed in a group of 5,209 hypertensive patients referred in two hypertension Clinics in Paris from 1976 to 1985. Patients were included in the study if they fulfilled the following criteria: 1) at least four visits in the clinic, 2) follow-up period greater than 6 months, 3) initial diastolic blood pressure greater than or equal to 90 mmHg and/or presence of an antihypertensive treatment. After a mean follow-up period of 43 months, blood pressure was reduced from 177/105 mmHg to 148/89 mmHg. However, in spite of at least two antihypertensive drugs, 16.7 p. 100 of these patients had a diastolic blood pressure above 95 mmHg at the end of the follow-up period and were defined as uncontrolled hypertensives (UH). By comparison with controlled hypertensives (CH), UH patients were more frequently males (67.9 vs 56.6 p. 100, p less than 0.001), had a greater known duration of hypertension (11.6 vs 8.7 years, p less than 0.001), and presented at the first visit with higher blood pressures (188/113 vs 174/103 mmHg, p less than 0.001/p less than 0.001), despite a higher rate of antihypertensive treatment (66.6 vs 53.8 p. cent, p less than 0.001), a higher ponderal index (26.3 vs 25.3/kg/m2, p less than 0.01) and a higher prevalence of end-organ damage (23.2 vs 16.3 p. 100, p less than 0.001). Sokolov index, serum creatinine and uric acid levels were higher among UH than among CH patients.(ABSTRACT TRUNCATED AT 250 WORDS)
"ARTEMIS" is a standardized and computerized medical file which is intended for improving the follow-up of hypertensive patients, the efficacy of treatment and for realising national-wide surveys. The software "LIED" of data base for "ARTEMIS" is nowadays transposable on mini-computer. In Nephrology Unit of General Hospital from Colmar, the system has been working since September 1985 with MICRO-MEGA E 32 (Thomson). The administrative and medical data are directly acquired by the doctors and secretaries of the Unit on a conversational mode from six terminals. There is no writing collecting of data. An evaluation of the system was realized with the 113 first hypertensive patients. The results were compared to those obtained from patients of Paris area.
Artificial intelligence techniques and expert systems are graduating from research laboratories to enter many human domains of activities. However, initial expectations of the seventies have been transformed with time to a more sober reality. Starting from examples in nephrology, this paper tries to give a balanced view of this new technology. Justification, indication and limitation of present expert systems are discussed as regards their possible goals. The respective roles of the experts and knowledge engineers are described. The need to integrate the artificial intelligence approach into present patient database management systems in order to build up expert database systems is evaluated.
An expert system has been integrated to the data management system of the ARTEMIS programme for hypertensive patients. The patient database, which has been used since 1975, contains the medical records of about 20,000 patients. Information is interactively entered by physicians, nurses and secretaries on video display units. The computerised medical record has replaced the traditional handwritten medical record. The database management system is used to produce different summary reports (inpatient and outpatient care) and personalized recall letters which are mailed to the patients before their appointments. Suggestions provided by the expert system include additional information to be obtained (complementary patient interrogation, biological or radiological investigations, etc.), possible causes of hypertension, and medical prescriptions. The information base allows the description of both static knowledge (in the form of a semantic network) and dynamic knowledge (in the form of production rules). The inference system sequentially uses a combination of forward and backward chaining and performs both exact and approximate reasoning. The diagnostic performance of the expert system was evaluated in 100 cases of hypertension (50 of essential hypertension and 50 of secondary hypertension. Concordance between the diagnosis proposed by the expert system and the one proposed by the specialist was achieved in 92% of secondary hypertension cases and 88% of essential hypertension cases. It is suggested that the integration of data and knowledge management might enhance the overall acceptance by medical staff of a computerised system, and facilitate the validation of a knowledge base.
Taking over a chronic disease like diabetes in a hospital clinic raises multiple problems. Large numbers of diabetic patients and prolonged follow-up periods result in a mass of data that only computers can control. MELLITEE is a computerized system developed to facilitate the longterm management of patients and to help in maintaining a high standard of care. It includes a structured and standardized medical record. Physicians of three Parisian hospital clinics agreed on the minimum content of the record. MELLITEE is operated at the Saint-Louis Hospital on a 68,000 based mini-micro computer (Fortune/Thomson Micromega-32), running under the Unix operating system and with the Lied data base management system. Data are keyed directly into the computer by physicians, nurses and dietitians from throughout the department. On-line registration of information allows the suppression of the corresponding part of the usual paper record. The clinical data base obtained from administrative and medical information can be used to facilitate more effective patient follow-up and clinic management. The system is to be set up in the other collaborating centres in the near future, allowing pooling of data. It will also provide long-term information which can be used for evaluation of care and epidemiological research.
An Expert System (ES) has been connected to a database management system for the management and follow-up of hypertensive patients. The patient data base, called Artemis, contains approximately 18,000 medical records. About 90% of the initial informations used by the ES is contained in the medical records of the Artemis data base. The knowledge base consists of 870 rules. A first group of rules allows the description of knowledge structures (hierachies, graphs and mutual exclusions). The second group consists of production rules which describe the dynamic reasoning of the expert. The inference engine uses a combination of forward and backward chaining. The ES produce diagnostic hypotheses (possible causes of hypertension) and therapeutic suggestions before and after requiring additional information (patient supplementary interrogation, biological or radiological investigations). The evaluation of the diagnostic performance of the ES was made on 40 confirmed cases of secondary hypertension (SH) and 40 cases of essential hypertension (EH). The initial initial diagnosis, just after the forward chaining step, was correct in 17 cases of SH and 32 cases of EH. The final diagnosis proposed after several steps of forward and backward chaining was correct in 37 cases (92%) of SH and 36 (90%) of EH. Averages of 5 (EH) and 8 (SH) questions were formulated by the ES to reach the final diagnosis. The integration of the ES to the database is expected to facilitate the validation of the knowledge base and to enhance its overall acceptability. Whether or not such an integration will be useful and accepted as a complementary tool by physicians remains however an open question.