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Biomedical subjects

A J Valleron

Publications and source records attributed to A J Valleron.

At least 19 recordsLinked to original sources
PubMed1992

Epidemiologic mapping using the "kriging" method: application to an influenza-like illness epidemic in France.

This paper presents the application of a technique from the earth sciences, the "kriging" method, to the field of geographic epidemiology. Both the principles of the method and the basic equations are given. A key advantage of the method is that it relies on an analysis of the spatial variability of the data and allows the representation of the variable under study as a continuous process throughout a country. Application of the kriging method to the geographic distribution of an epidemic of influenza-like illness in France is discussed.

Epidemiologic Methods↗
PubMed1992

The French communicable diseases computer network: a technical view.

This paper describes an information system (IS) established in France in 1984 for the national surveillance of communicable diseases. This IS is based on a videotex server and a relational database management system. The videotex server is the IS front-end. It performs the following functions: interpersonal communications, synthetic information retrieval into an epidemiologic info-base and data entry owing to its specialized applications. The relational database management system allows the user to manage and consult an epidemiologic database updated in quasi-real time. Several specific tools have also been developed in order to enhance data representation and analysis and the decision support capabilities of the IS.

Algorithms↗
PubMed1992

Six years of public health surveillance of measles in France.

Data provided by the Sentinel General Practitioners (SGP) to the French Communicable Diseases Computer Network (FCDN) have been used to present the epidemiological characteristics of measles observed during a 6-year period in France. The estimated annual incidence rates per 100,000 population were 376 in 1985, 603 in 1986 and 983 in 1987, then declined during the following 3 years to 297, 258, and 263 per 100,000 population in 1988, 1989 and 1990 respectively. There is a marked seasonal change with a high early summer peak. The mean age among the cases for the 6 years of study varied from 5.4 to 6.0 years. There is an increase in the percentage of cases with a past history of measles vaccination, from 6.7% in 1985 to 12.8% in 1990. This increase may be interpreted as a consequence of a substantial increase of the vaccine coverage during the same period.

Adolescent↗
PubMed1992

A new approach to estimating AIDS incubation times: results in homosexual infected men.

STUDY OBJECTIVE: The aim was to develop a new approach for estimating the incubation period of acquired immunodeficiency syndrome (AIDS), based on age distributions. DESIGN: Incubation period was expressed as the difference between age at time of diagnosis and age at time of contamination. Assuming independence between age at time of infection and incubation period, the age distribution of newly diagnosed AIDS cases is thus the convolution product between the distributions of the age of freshly infected patients and of the incubation times. AIDS incubation time can therefore be estimated from the age distribution of newly HIV infected subjects and newly diagnosed AIDS cases. SUBJECTS: Subjects were 2220 AIDS cases diagnosed until 1987, reported to the Ministry of Health, France, and 172 subjects discovered to be HIV-1 seropositive during a blood donation in Paris between August 1985 and July 1988. In both groups, the only known risk factor was homosexuality. MAIN RESULTS: The estimated median incubation time was 9.9 years (90% CI 9.0-10.9 years). Confidence intervals were narrow, even when taking into account the uncertainty in serodetection delay (90% CI 6.7-13.5 years). CONCLUSIONS: The incubation estimate is as accurate as previous estimates based on other models. This technique could therefore be applied to other risk groups.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Prevalence of obesity: a comparative survey in France, the United Kingdom and the United States.

We investigated the differences in the prevalence of obesity between France, the United Kingdom and the United States in 1988. The analysis was made on a total sample of 5580 subjects, representative of the population aged 16-50 years in the three countries. The same questionnaire was used in all three countries. Body mass index (kg/m2) was used to assess corpulence. Significant differences in the prevalence of obesity were observed among the three countries: 7% of the population in France was obese, 9% in the UK and 15% in the USA (P less than 0.001). There was a strikingly high percentage of very obese women (more than 50% overweight) in the USA (8% of the population) as compared to the two European countries (2% in France and 3% in the UK). In all three countries, obesity was related to sex, age, level of education, marital status, physical exercise and smoking. An inverse association was found between obesity and alcohol consumption in the USA, but not in France nor in the UK. In men, prevalence of obesity remained significantly higher in the USA than in France or in the UK when adjusting for the obesity-related factors. In women, differences in prevalence of obesity between the three countries varied according to the level of exercise, income and alcohol consumption.

Adolescent↗
PubMed1992

Evaluation of clinical trials of immunomodulators for prevention of recurrent respiratory infections in children.

Despite numerous clinical studies showing "significant differences" in favour of immunomodulators versus placebo in the treatment and/or prevention of recurrent respiratory tract infections, the efficiency of such treatments is still not readily acknowledged by a large part of the medical profession nor by governmental authorities in several countries. In an effort to analyze the causes of this scepticism we performed a retrospective study of 15 clinical trials, using a series of quality assessment criteria. From the results of our analysis we propose a series of recommendations for improving the quality of clinical trials with immunomodulators. Furthermore, in order to avoid suspicion of a publication bias, we recommend setting up a registry of all ongoing clinical studies with immunomodulators.

Adjuvants, Immunologic↗
PubMed1992

HIV antibody testing in France: results of a national survey.

Data from a knowledge, attitudes, and behavior survey conducted at the end of 1988 suggest that 13% of the population in France, aged 16 to 50 years, had been tested for HIV antibodies. Geographical differences in testing were observed, with a greater number of respondents tested in the regions where AIDS is most prevalent. Important variations in the percentage of HIV antibody-tested persons were found in relation to age, education, and occupation, but not to gender. Multiple logistic regression analysis identified significant predictors of HIV antibody testing. Behavioral predictors were multiple partners (odds ratio = 2.4), anal intercourse (odds ratio = 1.8), and drug use. A positive relationship was demonstrated between HIV testing and condom use. These correlations could indicate that the opportunity for anonymous and free testing encourages high-risk individuals to be tested.

AIDS Serodiagnosis↗
PubMed1991

French intravenous drug users: knowledge and sexual behavior change.

In a population based survey conducted in France in 1988, 41 respondents reported present or past intravenous drug use. Controlling for age and gender, intravenous drug users (IDUs) engage in more high risk sexual behavior than the general population (sex with other IDUs, multiple partners), but they do not use condoms more frequently. They are five times more likely to have had an HIV test.

Acquired Immunodeficiency Syndrome↗
PubMed1991

A routine tool for detection and assessment of epidemics of influenza-like syndromes in France.

A regression model for the nonepidemic level of influenza-like syndrome has been estimated from the 55,200 cases collected between October 1984 and August 1988 using the French Communicable Diseases Computer Network. The start of a major epidemic in 1988-89 was detected early. The size of the epidemic, for the entire country, was estimated at approximately 4.3 million cases. The excess cost of sick-leave, among those of working age, was estimated at $86 million.

Disease Outbreaks↗