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O Aase

Publications and source records attributed to O Aase.

13 recordsLinked to original sources
PubMed1999

Clinical experience with a decision support computer program using Bayes' theorem to diagnose chest pain patients.

A decision support computer program (DSP) was used by the emergency room physician as a diagnostic tool on patients admitted with acute chest pain to guide the referral of these patients either to the Coronary Care Unit (CCU) or general ward. The DSP used Bayes' theorem on 38 anamnestic and clinical variables to classify patients into one of nine diagnoses. During a six months trial period 32 physicians used the DSP to diagnose 493 patients admitted with acute chest pain. The physicians referred the patients to CCU or general ward based on their clinical judgements, the ECG findings and the diagnostic estimates given by the DSP. The program correctly diagnosed 150 (84%) of 178 patients with acute myocardial infarction and 63 of 112 patients with unstable angina. However, acute ischemic heart disease (acute myocardial infarction or unstable angina) was correctly classified by the DSP for 259 (89%) of 290 patients. By using the DSP, the number of patients unnecessarily referred to CCU was reduced from 35% to 19% and the number of patients in need of CCU observation misallocated to general ward was reduced from 13% to 10%. Thus, use of the DSP in the emergency room on easily available anamnestic and clinical variables may improve referrals to the CCU, optimize therapy and resource use.

Adult↗
PubMed1993

Decision support by computer analysis of selected case history variables in the emergency room among patients with acute chest pain.

A computer system to be used in the emergency room has been developed for estimating the risk of acute coronary heart disease (ACHD). The system uses data on 38 case history and clinical variables collected consecutively over a year from 918 patients with acute chest pain. A statistical procedure based on Bayes' formula is used to estimate disease probabilities. A quadratic scoring rule was used for variable selection. The score increased markedly until 15-20 variables had been added, reached a maximum after inclusion of about 30 variables and then deteriorated slightly. Thus, the number of variables carrying additional information on the presence/absence of ACHD seems to be much larger than the number normally utilized by doctors and by other decision support systems. Reclassification into two groups, those with and without ACHD, gives a diagnostic accuracy of 89%. We conclude that analysing detailed case histories by computer is a promising decision support system for use in the emergency room as a supplement to ECG analysis.

Angina, Unstable↗
PubMed1993

Prospective evaluation of an EDB-based diagnostic program to be used in patients admitted to hospital with acute chest pain.

A recently designed computer based decision support system (DSP), almost exclusively based on case history data, was developed to facilitate immediate differentiation between patients with and without urgent need for coronary care unit (CCU) transferral from the emergency room, and additionally to distinguish between patients with and without acute myocardial infarction (MI). One-year's prospective testing in a consecutive series of 1252 patients with acute chest pain revealed that the DSP, used in addition to ECG and clinical examination, demonstrated a sensitivity of 96% in the detection of patients in need of CCU observation (MI-sensitivity of 98%), and a specificity of 56% in excluding patients who were not in need of CCU observation. The proportion of referrals to the CCU judged to be unnecessary was only 17% of the total number of patients seen in the emergency room.

Angina, Unstable↗
PubMed1992

Standardized use of simple criteria from case history improves selection of patients for cardiac-care unit (CCU) admission.

A simple algorithm, which improves the diagnostic performance in patients arriving with acute chest pain in the emergency room, has been developed. The algorithm is solely based on information immediately available to the physician and includes elements from ECG, clinical findings and case history. As postulated, a stepwise use of all these variables improved the diagnostic accuracy and reduced the false positive cardiac-care unit (CCU) referral rate in a prospective study of 1450 patients admitted with acute chest pain. Compared to previous hospital practice during a preceding control period, sensitivity in diagnosing patients with unstable ischaemic heart diseases increased from 86% to 94% (P < 0.01), and specificity increased from 44% to 56% (P < 0.001). Accordingly, accuracy increased from 67% to 81% (P < 0.001), and false positive CCU-admission rate decreased from 35% to 19%. The greatest improvement in physician's diagnostic decisions was observed among patients without clear-cut signs of acute ischaemic heart disease on admission.

Algorithms↗
PubMed1991

Rapid and correct diagnosis of myocardial infarction: standardized case history and clinical examination provide important information for correct referral to monitored beds.

The value of thorough examination of the case history as a diagnostic tool on hospitalization of patients with suspected myocardial infarction was investigated in three independent prospective studies. Use of a limited number of pain-related elements (= 'criteria'), that had already been obtained in the emergency room, could improve the decision on whether or not to admit patients to the coronary-care unit. As an example, in one of the studies, use of such criteria would have reduced the number of 'unnecessary' coronary-care-unit admissions from 298 to 162, a 46% reduction (P less than 0.001). In the same patient sample, use of the criteria could have reduced the number of patients with definite acute myocardial infarction, admitted to the general wards, from 47 to 22, a 53% reduction (P less than 0.01). These favourable results were confirmed in the two independent, smaller-scale studies.

Coronary Care Units↗
PubMed1991

First myocardial infarction: 5-year survival predicted from routine clinical, laboratory, and radionuclide findings during the acute stage.

Five-year survival amongst 485 consecutive patients with their first acute myocardial infarction (AMI) was 78.2%. Univariate survival analysis showed that the following variables during the acute stage were of prognostic significance for survival: signs of left ventricular heart failure, enlarged cardiac volume, pulmonary congestion on chest X-ray, anterior myocardial infarction on ECG, and low left ventricular ejection fraction (LVEF), whereas enzyme analysis and Q/non-Q signs on ECG were not. In the multivariate analysis two equivalent models were found. The first pinpointed age and LVEF as independent predictors of mortality, and the second age and left ventricular heart failure. Finally, our subcohort of patients aged less than the mean 63 years and with normal LVEF values of greater than or equal to 50%, or no left ventricular failure had an observed survival for 5 years close to an age- and sex-matched group from the Norwegian population.

Adult↗
PubMed1990

[Development of a computer program for early diagnosis of acute myocardial infarction].

A standardised case history was obtained for 1,163 patients admitted to the Central Hospital of Akershus due to suspected acute myocardial infarction. From this database, a computer program was developed for establishing early diagnosis of acute myocardial infarction. In a given patient the program calculates the probabilities of the different conditions giving rise to the particular chest pain history by applying Baye's conditional probability approach. The program proved valuable as a supportive clinical tool of decision in patients admitted with acute chest pain.

Diagnosis, Computer-Assisted↗
PubMed1990

[Testing of a computer program model for the diagnosis of suspected acute coronary disease].

A computerized diagnostic system to be used in patients with acute chest pain was recently developed in our department, and was tested prospectively in 213 consecutive patients with acute chest pain. In our study, the computer system almost invariably improved the decision as to whether or not admission to the coronary care unit was necessary. Thus, compared with decisions made by the emergency room physicians the computer system would have reduced by approximately 75% the number of patients with acute myocardial infarction who are incorrectly referred to the general ward. The system would also have reduced by the same figure the number of cases wrongly placed in the coronary care unit. Thus, in patients admitted with acute chest pain, the use of our computerized system would have improved both diagnostic accuracy and correct referral of patients from the emergency room.

Chest Pain↗
PubMed1990

[The importance of medical history taking in evaluating and monitoring needs in suspected myocardial infarction].

In patients referred to the hospital with a suspicion of acute myocardial infarctions immediate diagnostic accuracy is improved by using a strictly standardized case history upon admission. Thus, the number of patients with proven acute myocardial infarctions erroneously referred to a general ward instead of to the coronary care unit wound have been reduced by one third, and unnecessary referral to the coronary care unit of patients in whom acute myocardial infarctions were not diagnosed would have been reduced by the same amount. Our study emphasizes the important of obtaining a thorough, standardized case history in patients with suspected acute myocardial infarctions. This would improve both patient care and the optimal use of coronary care unit facilities.

Coronary Care Units↗
PubMed1989

Interaction of naloxone and timolol on maximal exercise capacity and the subjective perception of fatigue.

The effect on exercise performance and on the subjective perception of fatigue of the opioid receptor blocker naloxone, the nonselective beta-blocker timolol, and the combination of these two was studied in a double-blind randomized cycle ergometry test in healthy young men. Cumulative work at exhaustion was reduced by 25% after timolol (P less than 0.002) and by 34% after naloxone/timolol (P less than 0.02) but not after naloxone, compared with placebo. Naloxone alone had no influence on the subjective perception of fatigue (Borg scale rating), but significantly higher ratings were obtained by timolol and by naloxone/timolol. The present study does not support the hypothesis that opioid peptides are of importance for maximal exercise capacity and subjective perception of fatigue during short-term dynamic exercise in healthy young men.

Adult↗
PubMed1989

Do X-ray determined cardiac volume and signs of congestive heart failure provide additional prognostic information after myocardial infarction if the left ventricular ejection fraction is known?

Cardiac volume (CV) was measured and indices of pulmonary congestion (PCG) were judged from routine chest films taken post myocardial infarction (AMI) in a consecutive series of 477 patients (340 first and 137 recurrent AMIs). Cardiac volume (CV) and signs of PCG were compared to left ventricular ejection fraction (LVEF), measured with isotope technique, and the prognostic value of all the parameters was assessed after 1 and 5 years. The accuracy of CV and PCG in predicting impaired LVEF was low (62% and 50% respectively). Although specificity is suboptimal, however, these parameters provided valuable prognostic information. For example, patients with signs of PCG had a very high 1 and 5 years' mortality, and two-thirds of those who died during the first year of observation had enlarged CV. The independent value of LVEF determination was mainly observed in re-AMI patients. A more restricted use of this expensive procedure may therefore be recommended.

Cardiac Volume↗
PubMed1983

A new method with fiberoptic transducers used for simultaneous recording of intravesical and urethral pressure during physiological filling and voiding phases.

A new technique using fiberoptic transducers for simultaneous registration of intravesical and urethral pressures during the physiological filling and voiding phases is described. The method, which is simple, exact and stable, was used on several patients with different urological problems. The study shows that the measurement technique and the fiberoptic transducer system are suited for clinical use.

Adult↗