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Biomedical subjects

A Alperovitch

Publications and source records attributed to A Alperovitch.

At least 73 records · Page 4Linked to original sources
PubMed1983

Controlled assessment of diagnostic techniques: methodological problems.

The increasing requests for diagnostic tests is one of the many causes of rising costs in health care systems. Many health care professionals think today that this increase could be reduced if diagnostic tests were accurately assessed, as are drugs. If there are similarities between a controlled treatment trial and a diagnostic method trial, there are also many differences relating to the sample size, the choice of criteria for final judgment, the study design and the clinician's behaviour when faced with the problem. These differences make it difficult to organise controlled trials of diagnostic techniques. A different approach using simulation methods and a decision tree appears more appropriate in the evaluation of diagnostic techniques.

Clinical Laboratory Techniques↗
PubMed1982

[Prognostic factors in acute digitalis poisoning].

The prognostic significance of various clinical and biochemical factors was investigated in 179 patients who had ingested more than 2 mg digitoxin. The mortality rate in this series was 17%. Supraventricular arrythmias had no influence on prognosis, but the death risk was higher in males and in patients with AV block. It increased with age, with digitoxin and potassium serum levels and even more with persistent hyperkalemia. Two other factors--previous heart disease and vomiting--were also significant in patients without heart block. Calculated on the basis of 4 clinical factors, the mortality rate varied from 2 to 74%. The death risk in acute digitalis poisoning can therefore be easily assessed simply from clinical criteria.

Acute Disease↗
PubMed1982

Geographical pattern of death rates from multiple sclerosis in France. An analysis of 4912 deaths.

4912 deaths related to multiple sclerosis have been identified in France during the period 1968-1977. The average annual death rate was equal to 0.96 per 100,000 population. Analysis showed a clear south to north increasing gradient. The study failed to find any geographic difference from data concerning 5173 amyotrophic lateral sclerosis (ALS) deaths which had been identified during the same interval. A noteworthy increase in the number of deaths related to ALS was observed over the study period.

Adult↗
PubMed1981

[Prognostic factors in acute digitalis poisoning (author's transl)].

The prognostic significance of various clinical and biochemical factors was investigated in 179 patients who had absorbed more than 2 mg of digitoxin. The mortality rate in this series was 17%. Supraventricular arrythmias had no influence on prognosis, but the death risk was higher in males and in patients with A-V block. It increased with age, with digitoxin and potassium serum levels and even more with persistent hyperkalemia. Two other factors, previous heart disease and vomiting, were also significant in patients without heart block. Calculated on the basis of 4 clinical factors, the mortality rate varied from 2 to 74%. The death risk in acute digitalis poisoning can therefore be easily assessed from simple clinical criteria.

Acute Disease↗
PubMed1981

Birth order and risk of multiple sclerosis: are they associated and how?

By analyzing birth order distribution in 107 patients with multiple sclerosis. Conditionally to the number of siblings in the 107 families, patients' mean birth order is significantly greater than expected. The number of patients whose bith order is equal to one is significantly smaller than the corresponding expected value. The present finding is in contrast to recent results observed by Isager et al. (1980) and this potential association deserves to be further investigated.

Birth Order↗
PubMed1980

Assessment of diagnostic tests.

An increasing number of clinicians is to day aware of the need to assess their diagnostic tools. Despite the fact that monetary value is only one of the components of the cost of a diagnostic test, economical problems are decisive stimuli for such an effort. Any diagnostic test involves a cost which is borne by the patient. So, test request is admissible only if its result may provide an useful information to the clinician. Behind this apparently simple formulation, one can foresee difficulties arising from the fact that criteria of judgement are essentially subjective, both for the cost and the usefulness. Several indices such as sensitivity, specificity, predictive values and accuracy, are commonly used for the assessment of the diagnostic value of a test. But these indices are not always calculated from valid data. And biases and lack of precisions are sometimes an obstacle to the transferability of the conclusions. Running from the most simple to the most complex, the aim of the assessment may be: 1. To judge the diagnostic value of a single test by reference to the final diagnosis or to the clinician's initial hypothesis. 2. To compare two diagnostic tests A and B and to discuss the possible interest of their combination. 3. To define the exact place of a test in a complex diagnostic strategy. In each of these situations, an ideal protocol can be envisaged. It will be often difficult to apply. But it will help to an informative description of both data and results, making easier utilisation of the conclusions of the study by the whole medical community.

Clinical Trials as Topic↗
PubMed1979

[Strategy for the diagnosis of thyrotoxicosis (author's transl)].

A study carried out on 808 patients examined because hyperthyroidism was suspected has shown that the most discriminating thyroid test is the free thyroxin index (FT4) in the plasma. For about 70% of the patients the comparison between the clinical diagnosis made by a clinician at his first interview and the results of FT4, leads one to an accurate assessment of the thyroid function. For the remaining 30% of the patients the assay of triiodothyronin (T3) in the plasma is the best laboratory test; it enables a diagnosis in 20% of those patients. It is therefore only in about 10% of the patients that more sophisticated laboratory tests would be necessary, such as TRH stimulation test and a technetium uptake whenever a scintigraphy is performed. Scintigraphy with technetium is only required to look for a possible toxic adenoma. In summary such a decision tree makes it possible to reduce considerably the cost of the diagnosis.

Cost Control↗
PubMedDate not supplied

CASCADE: a European collaborative study on vascular determinants of brain lesions. Study design and objectives.

Dementia is a highly prevalent disease that may have a cardiovascular component. White matter lesions and brain atrophy (brain abnormalities) are prevalent in dementia cases and might form part of the anatomical basis for the disease. We designed a multi-centre study, CASCADE (Cardiovascular Determinants of Dementia), to examine long-term (10-20 years) and short-term (5 years) cardiovascular risk factors for, and the cognitive consequence of, brain abnormalities. White matter lesions and atrophy are measured with magnetic resonance imaging. Cognitive function is measured with nine tests of memory and executive function. The studies included in CASCADE were ongoing and geographically spread throughout Europe to capture the cardiovascular risk gradient. In each study, a random sample of at least 100 subjects aged 65-75 years was selected who participated in the previous research examinations conducted by the respective centres. The objectives and design of the CASCADE project are described.

Aged↗