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Biomedical subjects

G Landrivon

Publications and source records attributed to G Landrivon.

10 recordsLinked to original sources
PubMed1996

[Decision analysis of congenital toxoplasmosis in the absence of exact knowledge of the treatment benefits and secondary effects].

Decision analysis seemed the appropriate method to bring out the interest of toxoplasmosis serology in children born from mothers who seroconverted during pregnancy. In particular it provides the possibility to choose between IgA serology, recently introduced in hospital practice, and IgM serology that is the reference test. We study a series of 96 children suspected of having congenital toxoplasmosis who were followed up until the age of one. A decision analysis is thereafter conducted by synthesizing data about clinical efficacy with the RBNCN ratio that is the net benefit of treating an affected person divided by the net cost of treating an unaffected person; these costs and benefits are clinical. The effectiveness of the treatment (sulphonamides in most cases) was not quantified. Therefore, we used the fact that the RBNCN ratio is equal to the number of healthy children likely to be treated unnecessarily in order not to leave untreated a contaminated child. Although data available in the literature and data from our study still remain insufficient to draw a final conclusion, IgA antibodies are significantly more sensitive than IgM antibodies (p < 0.01). Conversely, IgA antibodies are significantly less specific than IgM antibodies (p < 0.001). The sensitivity analysis shows that the IgA test is preferred to the IgM test if the mother is contaminated during the third trimester. On the other hand, for low prevalences, as observed in the first trimester, the IgM serology is more useful.

Anti-Infective Agents↗
PubMed1995

Comparison of the effects of different menstrual tampons on the vaginal epithelium: a randomised clinical trial.

The effects on the vaginal epithelium of three different menstrual tampons in normal conditions of use were studied in 41 women during the menstrual period. The vaginal epithelium was studied in a total of 123 cycles at a structural and ultra-structural level with colposcopy, vaginal smear and biopsy on TEM and SEM. One of the three tampons studied showed a lower level of abnormalities on colposcopy (36.6% vs. 56.1% vs. 68.3%), with an inverse correlation between the severity of the dryness and the quantity of blood absorbed by the tampon (4.2 g when the colposcopy was normal vs. 1.8 g in case of severe dryness). Cytology is not a good test for assessing the effects of tampons because of the high rate of acellular and uninterpretable samplings. The biopsy effects were defined according to their depth in the epithelium. The same tampon showed the lowest level in biopsy abnormalities. No correlation was found between severity of the colposcopy and biopsy results. Colposcopy can demonstrate the degree of severity of dryness or any other effect, but biopsy only confirms the effect and does not correlate the degree of severity. Materials and designs of tampons can play a role in reducing the drying effects to the vaginal epithelium.

Adolescent↗
PubMed1994

Data quality in a DRG-based information system.

The aim of this study initiated in May 1990 was to evaluate the quality of the medical data collected from the main hospital of the "Hospices Civils de Lyon", Edouard Herriot Hospital. We studied a random sample of 593 discharge abstracts from 12 wards of the hospital. Quality control was performed by checking multi-hospitalized patients' personal data, checking that each discharge abstract was exhaustive, examining the quality of abstracting, studying diagnoses and medical procedures coding, and checking data entry. Assessment of personal data showed a 4.4% error rate. It was mainly accounted for by spelling mistakes in surnames and first names, and mistakes in dates of birth. The quality of a discharge abstract was estimated according to the two purposes of the medical information system: description of hospital morbidity per patient and Diagnosis Related Group's case mix. Error rates in discharge abstracts were expressed in two ways: an overall rate for errors of concordance between Discharge Abstracts and Medical Records, and a specific rate for errors modifying classification in Diagnosis Related Groups (DRG). For abstracting medical information, these error rates were 11.5% (SE +/- 2.2) and 7.5% (SE +/- 1.9) respectively. For coding diagnoses and procedures, they were 11.4% (SE +/- 1.5) and 1.3% (SE +/- 0.5) respectively. For data entry on the computerized data base, the error rate was 2% (SE +/- 0.5) and 0.2% (SE +/- 0.05). Quality control must be performed regularly because it demonstrates the degree of participation from health care teams and the coherence of the database.(ABSTRACT TRUNCATED AT 250 WORDS)

Data Collection↗
PubMed1993

Cytomegalovirus infection--an etiological factor for rejection? A prospective study in 242 renal transplant patients.

The study aimed at analyzing the role of CMV infection as a risk factor for rejection occurring after CMV infection because of the clinical consequences of the prevention of CMV infection that might lead to the decrease in rejection episodes. Two hundred forty-two consecutive renal transplant patients were prospectively checked for the occurrence of CMV infection. CMV infection was defined virologically by a positive viremia or/and a positive viruria or/and a seroconversion or/and a significant rise of the anti-CMV antibody titers. Viremia, viruria, and serology were performed weekly for the first month and then at day 90, day 180, and every 6 months, and moreover if clinical symptoms related to a viral infection occurred. Rejection episode was defined by a creatininemia rise of 25%, after cyclosporine nephrotoxicity and urological complications had been discarded, and by the response to the antirejection therapy, steroids, or OKT3 in case of steroid-resistant rejection. The outcome factor was rejection episode occurring from day 4 after the diagnosis of CMV infection. A patient undergoing "a rejection episode after CMV infection" could also be exposed to other potential confounding factors that can be considered as risk factors of rejection among our patients. Rejection occurring before CMV infection was the main factor because it was linked both to CMV infection itself and to "rejection after." Thus infected and noninfected patients were randomly paired off. To the noninfected patient of the pair was attributed the date of a fictitious CMV infection that was the date of the CMV infection of the infected member of the pair. Therefore, "rejection after" and "rejection before" were defined in infected and noninfected patients of the pair according to the time of onset of CMV infection of the infected member of the pair. The incidence of CMV infection was 65%, 157 of the 242 patients were infected, and 85 not infected. Thus 85 pairs of infected-noninfected patients were studied. The incidence of "rejection after" the diagnosis of CMV infection was significantly higher in the group of patients with CMV infection: 45% among infected (38/85) versus 10.60% among noninfected (9/85) (P < 0.0001). Among the 85 pairs, 48 pairs were concordant in which patient of the pair evinced the same outcome factor: 43 showed no rejection after, and 5 showed one.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1993

[Analysis of the medical decision].

Analysis of clinical decision making is a quantitative method using probabilities to evaluate the process in uncertain situations. It provides a model of clinical decision making by integrating experimental and epidemiological data, the opinions of specialists and an assessment of the patient's state of health. There is also a place for the integration of the patients' opinions and of their quality of life. Using this information and eventually associating the cost of management, analysis of decision making tries to demonstrate a preference for a given strategy in a given clinical or public health problem. This article presents the methodological basis of analysis of decision making using a simple example of clinical cardiological practice and discusses the value of this method for debating a clinical choice with criteria integrating the patients' quality of life and the cost to society.

Cost of Illness↗
PubMed1992

[Myocardial infarction beyond the 48 first hours: treatment with calcium channel antagonists].

Calcium channel blocking agents prevent calcium entering cardiac and smooth muscle cells. With reduction of the blood pressure, heart rate and myocardial contractility, they reduce myocardial oxygen demand. By relieving spasm and coronary constriction, and dilating the collateral coronary vessels, they improve perfusion of the ischemic zones. The results in experimental infarction are contradictory: the reduction in the infarct size and ischaemia is not constant. In the Myocardial Infarction Study, a trial of lidoflazine in 1792 subjects followed up for an average of 5 years, there was no significant difference between the mortality rates of the two groups. In the Danish Verapamil Infarction Trial I, which included 436 subjects receiving 360 mg/day of verapamil or placebo, the 6 months mortality was less (NS) in the verapamil group (12.8%) than in the placebo group (13.9%) as was the reinfarction rate (7.8% versus 9.2%; NS). In the DAVIT II trial of 1775 subjects, treatment was introduced 9 +/- 2.7 days after admission. Mortality was lower (NS) in the verapamil group (11.1%) than in the placebo group (13.8%) and the recurrences were less common (p = 0.04) in the treatment group (11.0%) than with placebo (13.2%). The Secondary Prevention Reinfarction Israeli Nifedipine Trial is a comparison of Nifedipine 30 mg/day and placebo introduced 7-21 days after infarction in 2276 subjects. After 10 months, the mortality and reinfarction rate were similar in both groups, as in the SPRINT II trial (60 mg/day of nifedipine or placebo) at 6 months. In the Multicenter Diltiazem Postinfarction Trial of 2466 patients, Diltiazem 240 mg/day or placebo was administered 3 to 15 days after infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Which anti-ischemic treatment can be prescribed during and after the acute phase of myocardial infarction?].

After myocardial infarction, calcium channel blockers are the most prescribed anti-ischemic drugs followed by nitrate derivatives and beta blockers. In order to assess whether this attitude is justified by published data on their efficacy, a meta-analysis of trials of anti-ischemic drugs in myocardial infarction was performed. The early mortality was 13.3% in the group treated by IV nitrates in the acute phase of myocardial infarction and 17.2% in control groups, reducing the risk by a quarter (95% confidence interval of the odds ratio (CI): 0.55-0.95). When all nitrate derivative trials were grouped together, the reduction in the risk of death of 21% was significant (from 15% to 11.8%) (CI: 0.59-0.94). Although oral nitrate derivatives introduced during the acute phase and continued for several weeks induced a non-significant reduction in mortality of 16%, when given intravenously, the benefits on early and longer term mortality were unquestionable. The mortality was 9.8% in the groups treated by calcium channel blockers and 9.3% in control groups (NS); the recurrent infarct rate was 4.8% and 5.4% respectively (NS). In this family of drugs, there was no product which distinguished itself from the others with regard to beneficial or adverse effects. The early mortality decreased from 9.2% to 8.2% in the groups treated by oral beta-blockade--a risk reduction of 10% (NS) and from 4.2% to 3.7% with intravenous beta-blockers--a risk reduction of 12% (p = 0.03). Late mortality decreased from 9.4% to 7.6%, a reduction of 20% (p < 0.00001) in long term trials.2+ contraindication of betablockers in patients without cardiac failure.

Adrenergic beta-Antagonists↗
PubMed1992

[Mammary microcalcifications: is there a consensus on interpretation and management?].

Twenty two view mammograms without magnification, with microcalcifications corresponding to non palpable breast lesions, were submitted to 23 experienced observers, either gynaecologists or radiologists. These mammograms consisted of 10 malignant lesions and 10 benign lesions; all of them underwent surgical procedures. The microcalcifications were graded and categorized into one of the four groups: malignant; suspect; slightly suspect; benign. One of the four options was proposed: biopsy; mammogram within 3 months; mammogram within 6 months; mammogram within a year. Twelve observers out of 23 have referred to a classification. The mammograms were assessed according to a consensus. The validity of that diagnostic test was studied in various clinical situations and the lack of homogeneity of the responses was quantified. In the trade-off situation between sensitivity and specificity (suspect or malignant considered as positive), sensitivity is 50% and specificity is 70%. Moreover, the responses are not homogeneous at all and this lack of homogeneity is found to be statistically significant, greater than by chance alone. The diagnosis of cancer is more frequently put forward by the radiologists. This study explains the low predictive value of non palpable microcalcifications undergoing surgical procedures: from 11.5 to 44% in the literature. Similarly, there is no agreement on the frequency of the follow-up for these microcalcifications when they do not lead to surgical procedures.

Breast Diseases↗
PubMed1991

Meta-analysis.

Meta-analysis corresponds to all systematic methods which use statistical techniques for combining results from several independent studies. The aim is to get a consistent estimation of the global effect of a procedure on a specified outcome. The technique allows us to increase the power of statistical testing, and to get information which cannot be drawn from one individual study. Two approaches are possible, and often combined: the qualitative approach consists of weighing various studies according to their methodological quality; the quantitative approach consists of pooling the results of different studies, in order to generate results with a higher statistical power. A meta-analysis is a long and rigorous process, which follows several steps: statement of objectives; definition of articles inclusion and exclusion criteria; literature search; collection of data and evaluation of the quality of each study; tests for homogeneity; pooling; sensitivity analyses; presentation of results; and conclusions. Meta-analysis has several advantages: it estimates the size of an effect; it improves the generalizability; it compels to rigor; it lessens the part of subjectivity. When meta-analysis is cautiously and properly done, it brings new useful information, and helps physicians and health policy makers in answering to a specific question.

Data Collection↗