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A Bouckaert

Publications and source records attributed to A Bouckaert.

At least 19 recordsLinked to original sources
PubMed1995

Modelling mortality and morbidity of newborns.

Data of 10,514 singleton births collected over a ten year period at a single hospital are analysed and models linking birthweight and gestational age with mortality and morbidity defined by low Apgar scores are constructed and compared. Based on these models, charts of mortality and morbidity are drawn and compared with common charts of birthweight centiles. Classification rules for newborns at risk are defined by iso-mortality contours, marginal birthweight centiles, and birthweight centiles adjusted by gestational age, respectively, and compared using receiver operating characteristic (ROC) curves. The results suggest that, as far as neonatal mortality is concerned, classification rules based on simple marginal birthweight centiles perform almost as well as iso-mortality contours and considerably better than birthweight centiles adjusted for gestational age.

Apgar Score↗
PubMed1994

The probability of a successful treatment of infertility by in-vitro fertilization.

The objective of this study was to define several estimates of the success rate of in-vitro fertilization and embryo transfer treatment in relation to treatment outcome. The data were collected in a retrospective study of 591 patients treated during 3 years in one Belgian university hospital. Several models used for evaluating the treatment of infertility were fitted to the data (logistic model, binomial model, double binomial model, exponential model, the Speirs model. The number of oocytes retrieved and the proportion of fertilized oocytes at the first attempt can be used as prognostic factors. According to these factors, the success rate after five attempts varies from 28 to 88%.

Belgium↗
PubMed1994

Molecular phylogeny of part of the env gene of HIV-1 strains isolated in Côte d'Ivoire.

OBJECTIVES: To examine the genetic variation of HIV-1 isolates in Abidjan, Côte d'Ivoire, and to determine the extent to which phylogenetic trees based on sequence information of part of the env gene containing the principal neutralizing domain are representative for documenting genetic variability. DESIGN: Phylogenetic comparison of 13 HIV-1 strains isolated from patients in Abidjan with previously documented HIV-1 strains of different geographic origin. METHODS: To sequence a 900 base-pair fragment of the env gene containing V3, V4, V5 and the beginning of gp41 of three to four clones per isolate. Phylogenetic tree analysis was performed with the software package TREECON. RESULTS: Eleven HIV-1 isolates of Abidjan were classified as genotype A, while two were classed as genotypes B and D. Intra-genotype A distances at the nucleotide level were a maximum of 14.1%. Inter-genotype distances between genotype A and genotypes B, C, and D varied from 16.0 to 22.6%. Phylogenetic trees, based on sequence data of a 300 base-pair fragment containing the V3 loop, showed significant differences in tree topology and statistical confidence with phylogenetic trees based on sequence data of the 900 base-pair env fragment. CONCLUSIONS: Genotype A Côte d'Ivoire HIV-1 strains, which comprise 11 out of 13 isolates, predominate in Abidjan, which may indicate a local burst of particular variants. Phylogenetic trees should be interpreted with caution when based on a more limited number of nucleotides, such as the V3 region.

Base Sequence↗
PubMed1993

A regression model for the rate of success of in vitro fertilization.

The treatment of infertility by in vitro fertilization involves several aspects of human reproductive physiology. Since failures are still numerous and since improved techniques are becoming increasingly available, it is important to develop a model where the components of success are identified, allowing estimation of the occurrence of these components of success in the infertile population. The model of Speirs reduces these components to two: uterine receptivity and embryo viability. The probabilities of uterine receptivity and embryo viability were estimated here in a retrospective study of patients in a Belgian hospital sample. For comparison, Australian and U.S. data were used. It was shown that the estimate of uterine receptivity for the Belgian sample is located between the estimates for Australian and U.S. samples. In view of the psychological problem of repeated unsuccessful attempts at in vitro fertilization in some patients, it is important to be able to single out some prognostic factors that would allow more precise estimation of the probability for success in each case. A regression method was developed for that purpose. Only the effect of age, in the Belgian sample, was found to influence uterine receptivity significantly.

Adult↗
PubMed1992

[Weight and length of newborns. Differences between boys and girls].

Examination of 8,312 deliveries shows that the difference in weight between boys and girls at birth can be explained completely by the difference in their length. The sex of the child has no influence on the length of the pregnancy. This is influenced by the birth order, the propensity to smoke (tobacco), the mother's weight gain in pregnancy and her social level. The speed of intrauterine growth is influenced by the sex of the fetus, the number of pregnancies she has had, by tobacco, and by the amount of education she has had and her weight gain in pregnancy.

Belgium↗
PubMed1990

[An epidemiological study of hypercholesterolemia in the Grand Duchy of Luxembourg].

Epidemiology of hypercholesterolemia in the Grand Duchy of Luxembourg was studied by the mean of a questionnaire filled out by 17 physicians. 113 patients (50 men and 63 women) were recruited. 43 patients had an isolated hypercholesterolemia (type IIa) and 63 patients had a type IIb. Analysis of associated risk factors showed large variations (13.2% of patients had diabetes, 61% were sedentary). However, 33.5% of patients had at least one associated risk factor. The nutritional assessment showed the well-known dietary errors. A two month's treatment with ciprofibrate has shown a 20% decrease of total cholesterol and a 32% decrease of triglycerides. No serious adverse events were reported.

Adult↗
PubMed1990

[Screening for congenital hip dislocation in Belgium. Results of a survey in maternity wards. Proposals].

Congenital dislocation of the hip (CDH) is probably more frequent in our country than generally appreciated. In most European countries, the incidence of CDH varies from 6 to 20 per thousand living births. The screening for the condition is organized with the help of public services. Our purpose was to survey the maternity wards to estimate the extent of the occurrence in Belgium. A volunteer orthopedic surgeon met with the pediatrician and the obstetrician in every hospital with a maternity ward to complete a questionnaire. We present a detailed analysis of the results of the survey and propose a better system for screening.

Belgium↗
PubMed1989

[Prevention of beta-thalassemia in the French speaking part of Belgium. I. Epidemiologic, clinical, psycho-social and economic justifications].

A study was jointly conducted by three universities in order to determine whether the systematic prevention of beta-thalassaemia and related affections is justified in the French-speaking part of Belgium. In the entire geographical area considered, 19.1% of the population are foreign; 19.2% of births take place within foreign families. Around 59.7% of foreigners come from regions where beta-thalassaemia is endemic. The ethnic minorities are mostly concentrated in the cities and notably in Brussels. Around 4.1% of the minorities ethnically at risk are carriers of beta-thalassaemia. Births of new cases of thalassaemia major can be estimated at 2.9 per year, which would result, in the absence of prevention, in a population of 130 cases of thalassaemia major. In recent years, patient care has improved considerably, as demonstrated by an increasingly early diagnosis and institution of chelating therapy with an attendant gradual drop in ferritin levels. However, study of age histograms reveals that care of patients in non-endemic regions is not as satisfactory as in endemic countries where complete haemoglobinopathy control programmes have been developed. Psycho-social questioning of a sample of families confirmed that thalassaemia major is an affection which seriously impairs the quality of life. Finally, calculations projected over 20 years revealed that systematic prevention would cost from 2.3 to 2.8 times less than a purely curative approach. The authors conclude that a body of epidemiological, clinical, psycho-social, and economic arguments justify without any doubt the prevention of beta-thalassaemia and related affections in the French-speaking part of Belgium.

Adolescent↗
PubMed1989

In-vitro fertilization: how many attempts before success?

Repeated attempts increase the overall rate of success of sterility therapy by in-vitro fertilization. The present study, using data collected between 1983 and 1987 in a Belgian hospital, attempts to investigate the expected number of treatment cycles before success is achieved. The answer requires some knowledge about the degree of independence between success probability and treatment duration. Using mathematical models of implantation, it can be shown that success probability actually decreases during treatment. A method for updating individual probabilities is suggested; it could be used as a prognostic estimation for women undergoing this kind of therapy.

Evaluation Studies as Topic↗
PubMed1989

[The prevention of beta-thalassemia in French-speaking Belgium. II. Proposal of a strategy].

Medico-social surveys and pilot experiments, conducted by the authors in Wallonia and Brussels at the request of the Ministry for the French-Speaking Community, have allowed the definition of a community-scale prevention programme. High-quality information, repeated at regular intervals and adapted to the different environments, is vital for effective voluntary screening. The contents of this information and distribution methods have been specified. Screening will take place on an occasional basis among people at risk who request it, or who accept it as an addition to other planned blood tests (curative or preventive consultations); microcytosis must be considered as a definite indication for further work up. Systematic screening is recommended in the framework of upper secondary education, through cooperation between volunteer teachers and the staff of school medical institutions; teaching methods and means have been reviewed.

Belgium↗
PubMed1987

Medical diagnosis: are expert systems needed?

An evaluation of the pitfalls of computer-aided diagnosis during the last ten years seems to show that increased emphasis on real clinical problems as well as increased use of medical knowledge are required. Since such an approach could fit into the 'expert system' framework, one should expect new developments in that research field to occur soon. However, expert systems can also be designed along the same concepts as previous models of diagnostic reasoning presumably with the same shortcomings.

Diagnosis, Computer-Assisted↗
PubMed1985

Fertility of male workers exposed to mercury vapor or to manganese dust: a questionnaire study.

The fertility of male workers exposed to mercury vapor or to manganese dust was assessed with the use of the questionnaire developed by Levine et al [1980]. In the mercury group (concentration of mercury in urine ranging from 5.1 to 272.1 micrograms/g creatinine), no statistically significant difference was found between the observed number of children and that expected on the basis of the reproductive experience of a well-matched control group. On the contrary, by comparison with their corresponding controls, the manganese-exposed workers exhibited a statistically significant deficit in the number of children during their period of exposure to the metal. The airborne concentration of manganese dusts at the different workplaces ranged from 0.07 to 8.61 mg/m3 with a geometric mean of 0.94 mg/m3.

Adolescent↗
PubMed1985

The diffusion of a vanguard technique: the case of nuclear medicine in Belgium.

How does a new technology spread across a country? Which are the factors influencing its spreading across time and space? We have attempted to answer to those questions through the example of nuclear medicine. We have used a macro-economic approach, based on regional and diachronic data (43 areas and three larger 'regions' from 1974 to 1982). Two separate fields have taken advantage of the use of radioisotopes: in vivo and in vitro tests. The rates of growth of those two techniques have been completely different and their future evolution will probably also be in sharp contrast. On the contrary, the regional distribution of the utilization rates is similar in both fields: it seems related to the density of specialists who are accessible for the patients and also to the regional ways of practice which feature the prescription of other types of tests.

Belgium↗
PubMed1985

Methods for estimating the duration of bacterial carriage.

In two cohort studies on asymptomatic pharyngeal carriage of meningococci and of streptococci among schoolchildren, four methods are used to estimate the duration of bacterial carriage. A first estimate of the mean duration is given by the quotient of prevalence by incidence rate. A second method is based on the estimation of the actual length of truncated observations. A third estimate is given by the analysis of carriage survivorship according to a life table. A fourth method is the fitting of a negative exponential model to the carriage survival curve. For meningococci, the estimates of the median duration of carriage range from 7.7 up to 10.2 months, and from 11.1 up to 14.5 months for the mean. For streptococci, the median values vary from 1.9 up to 2.1 months, and from 2.3 up to 4.4 months for the mean duration. The validity and the consistency of the different estimates are discussed.

Actuarial Analysis↗
PubMed1985

Simulation of vaccination and resistance in leprosy using an epidemiometric model.

Epidemiometric models are useful in studying disease dynamics in populations. Such a model was developed for leprosy and proved useful, but did not take into account age- and sex-specific incidence rates. This paper presents a new version of the model which makes provisions for age and sex differential rates according to the type of leprosy and which includes more realistic parameters for death rates, population variations, and natural growth rates. This new version of the epidemiometric model was used to stimulate the effects of various vaccines and drug resistance on the incidence of leprosy in a population.

Epidemiologic Methods↗