Search PubMed⌕ Search

Biomedical subjects

J F Chastang

Publications and source records attributed to J F Chastang.

16 recordsLinked to original sources
PubMed1996

Time-trend of sleep disorder in relation to night work: a study of sequential 1-year prevalences within the GAZEL cohort.

We examined two longitudinal hypotheses: the 1-year prevalence for night workers is consistently higher than for others; the time trend is steeper for night workers than for others. Subjects were 12,779 men (age 40-50) working at Electricité de France-Gaz de France, and recruited in the GAZEL cohort. Five questionnaires were sent to all subjects on 1989 through 1993. Self-reported occurrence of sleep disorder in the previous year was regressed on night work status in 1989 and covariates to estimate prevalence rate differences (PRDs). The estimated PRD for regular night workers versus others was 6.1% (95% CI, 1.1-11.1%). There was a common time trend of 1.4% per year (1.0-1.9%), and evidence of excess trend for regular night workers: 1.1% (-0.7-2.9%). Findings indicate that the effect of night work on sleep complaints manifests itself during the first year of night work and is permanent.

Adult↗
PubMed1996

Does lactose maldigestion really play a role in the irritable bowel?

Patients who met International Congress of Gastroenterology criteria for irritable bowel syndrome (IBS) and had breath hydrogen lactose testing were interviewed to determine whether detection of lactose maldigestion (LM) had an impact on their symptoms. Of 199 patients initially evaluated, 161 (81%) were contacted and asked to rate their symptoms. At baseline, 47 (29%) of the IBS group had LM. Before testing, 23 (49%) were aware that ingestion of lactose-containing food was associated with their gastrointestinal symptoms. Lactose-maldigesting IBS subjects (IBSLM, n = 47) and those who had IBS and no LM (n = 114) were similar in terms of age, sex, and ethnic background. Interviews performed 41 +/- 1.1 (SEM) months after baseline evaluation revealed no significant differences in abdominal pain, altered bowel habits, bloating/distension, mucus, and relief with defecation among those with IBS or LMIBS. Overall symptoms resolved, improved, did not change, or worsened in a manner not statistically different between IBS and IBSLM groups. IBSLM subjects (a) felt that identifying LM helped them gain awareness of food-symptom relationships (78.7%), (b) experienced some improvement in symptoms (83%), (c) were avoiding lactose foods (87.2%), or (d) used lactase enzyme supplements (38.3%). Identifying LM did not significantly affect rated variables.

Breath Tests↗
PubMed1994

A 10-year incidence survey of respiratory cancer and a case-control study within a cohort of nickel mining and refining workers in New Caledonia.

The incidence of lung, pleural, nasal, larynx, and pharynx cancer in relation to work in the nickel mining and refining industry was studied from 1978 to 1987 in the male population of the French territory of New Caledonia in the South Pacific. The results showed no greater risk in the population of nickel workers than in the general male population. The incidence of respiratory cancer in New Caledonia was found to be comparable to that of industrialized countries, except for pleural cancer for which there was an excess risk in New Caledonia. A case-control study within the cohort of nickel industry workers comprised 80 lung cancer, 12 larynx cancer, 20 pharynx cancer cases, and 298 controls, and took account of 18 substances to which workers were exposed, five of them nickel compounds. None of the substances, or any other occupational variable, was shown to increase the risk of respiratory cancer, except for cancer of the larynx in relation to level and duration of exposure to dust and engine exhaust fumes on mining sites (odds ratios ranged from five to 5.4 and were significant). These results provide no evidence that exposures specific to the nickel industry in New Caledonia increase the risk of respiratory cancer. This might be due to the involvement of less airborne nickel than the amount observed in positive studies elsewhere. The high incidence of respiratory cancer in New Caledonia, compared with other South Pacific islands, might be attributable to an environmental risk connected with the presence of mineral fibers in the geologic strata, as well as to tobacco and alcohol consumption levels similar to those prevailing in France.

Age Factors↗
PubMed1994

[Prevalence of health problems in the Gazel (EDF-GDF) cohort: regional distribution and disparities].

This study deals with regional differences in annual prevalence of 44 declared diseases or clinical disorders in 1989 in GAZEL cohort participants from "Electricité de France-Gaz de France" company. The studied sample consisted of 20,325 people, from 35 to 50 years old, living in France, who answered to a mail questionnaire in 1989. The collected data from one year were analysed. An overall "regional effect" was searched about every listed disease in the questionnaire. For this purpose, a logistic model, controlling for age and sex, was used. For comparing prevalence of a disease in one region with average prevalence, an odds ratio (OR) was calculated: it was defined here as the ratio of disease odd in the region to the average French odd. The regional effect was studied in greater detail for five diseases, making allowance for extra factors of adjustment (tobacco and alcohol consumption, Quetelet index, salary category, number of declared diseases). The regional effect remained significative for four diseases: hypertension with OR from 1.26 to 1.68 in northern regions, and from 0.63 to 0.75 in southeastern ones; osteoarthrosis with OR lower than 1 in western regions (0.60 to 0.79), and larger in the South (1.24 to 1.46); hyperthyroidism, goiter with OR elevated in Midi-Pyrénées (2.91) and Lorraine (1.82) [corrected]; renal stones with OR high in the South (1.85 in Provence Riviera). These results can be compared to known observations about geographical differences in mortality. They also suggest persistence of hazardous areas for some diseases.

Adult↗
PubMed1993

Effects on health and social well-being of on-call shifts. An epidemiologic in the French National Electricity and Gas Supply Company.

An investigation of the effects on health and social well-being of on-call shift work to cover emergencies outside working hours has been carried out by Electricité de France-Gaz de France, the French national company that supplies gas and electricity. This transversal survey compared a group of workers exposed to on-call shift work (n = 145) with a group that was not (n = 195). Each subject completed a questionnaire about the demands of his work, state of health, psychologic equilibrium using the Langner scale, and the impact of his job on social and family life. A "weekly report form," completed for 3 consecutive weeks randomly selected using a sampling plan covering the entire year to take into account seasonal variations, was subsequently filled in by 115 of the group exposed to on-call shift work and 167 of those who were not, to investigate events occurring outside working hours and sleep. The findings show that the main demands of being on-call were telephone calls, which were five times more numerous during the weeks on-call; this was accompanied by a shorter sleeping time (a mean of 6.8 hours versus 7.4 hours during a normal week) and more frequent tiredness on waking up (25.7% vs 13.2%). No particular disorder was found more frequently in the exposed group, but the psychologic equilibrium and family and social life of the workers in the on-call shift group were disturbed: some variables in the questionnaire and indices calculated from some items revealed adverse effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Psychological↗
PubMed1992

Level of education, lifestyle, and morbidity in two groups of white collar workers.

STUDY OBJECTIVE: The aim was to examine the relationship between level of education, lifestyle, and morbidity in two groups of male white collar workers, and to determine whether any differences found could be related to objective differences in working conditions. DESIGN: The study was a survey of a random sample of commercial travellers and a sample of men with sedentary occupations, representing two different groups of white collar workers. Survey interviews were conducted during the annual compulsory medical examination. Subjects were classified into three levels of education and differences according to level of education were studied in relation to 40 frequent health problems, lifestyle variables, body mass index, height, and working conditions. SUBJECTS: There were 1364 men in the commercial traveller group, mean age 39.5 years, and 525 men in the sedentary group, mean age 36.2 years. There were 22 exclusions because of unclassifiable levels of education and four refused to be interviewed. SETTING: The study took place in 11 towns in France. MAIN RESULTS: When age was taken into account there were only minor differences in the prevalence of health disorders. Lifestyle variables and height were clearly related to the level of education. Observed differences could not be explained by constraints or declared difficulties in working conditions. CONCLUSIONS: Differences in health practices related to level of education are observed even in groups that are relatively homogeneous socially. Lifestyle may be important as an intermediate determinant of health disorders among less educated people.

Adult↗
PubMed1992

Low-back pain in commercial travelers.

The role of occupational environment in the occurrence of low-back pain was analyzed for 1719 commercial travelers (1376 men and 343 women). At the beginning of the study (T0) the group was interviewed to determine current lifestyle and occupational factors associated with low-back pain during the previous 12 months. Twelve months later (at T1), a subsample of 1118 persons (893 men, 225 women) was reinterviewed to study the association between the incidence of low-back pain during the year of follow-up and the risk factors at T0. At T0 low-back pain was significantly related with time spent driving a car at work, comfort of the car seat, carrying loads during work, standing for long periods at work, smoking, and psychosomatic factors. At T1 driving 10 h/week or more, seat comfort, and psychosomatic factors were associated with first occurrence of low-back pain.

Adult↗
PubMed1990

[Comparison of observed and expected person-years: a simulated approach].

In Epidemiology, no simple test is available for comparing an observed number of exposed person-years with an expected number. The number of person-years is a sum of lengths of stays which is not normally distributed under the null hypothesis. A method is proposed and an example is given. The objective was to study in the French territory of New-Caledonia the relationship between past places of living and occurrence of respiratory cancers. The total observed number of person-years in a zone, among cases, was compared to an expected distribution, based on censuses and controlling for two confounding factors, period of stay and ethnic group. Different methods are compared: a test based on a simulated distribution, and parametric approaches with normality assumption. If the number of cases is small, the simulation test seems to be the best approach.

Analysis of Variance↗
PubMed1988

Correspondence analysis and logistic modelling: complementary use in the analysis of a health survey among nurses.

Logistic or other modelling approaches are often appropriate for studying epidemiological data. However, health surveys may be more complex. With numerous variables, there is a need for exploratory analysis. Parsimonious description of the data is also a useful complement to modelling. Correspondence analysis may be useful in such exploratory phases. An example of the complementary use of the two approaches is presented in the context of a health survey among nurses, which focused on the relationship between shift and night work, and declared health problems.

Adult↗
PubMed1988

A study of the interaction of alcohol drinking and tobacco smoking among French cases of laryngeal cancer.

Laryngeal cancer represents an important cause of cancer in France, and the individual effects of alcohol and tobacco on this cancer site are well known. However the problem of the interaction between these agents is less extensively documented, and the role of the high consumptions of alcohol has not been studied frequently. A case-control analysis was undertaken to investigate the joint effect of alcohol and tobacco by comparing 197 glottic and 214 supraglottic cancer cases to 4135 controls representative of the French general population. Heavy drinkers were available from the two groups of cases, the highest alcohol category being equivalent to a consumption of more than 2 litres of wine per day. The relative risks estimated for heavy drinkers and smokers were high, and the results indicated an even stronger effect of alcohol drinking and tobacco smoking on the upper part of the laryngeal region. Additive and multiplicative models were fitted to the data. The multiplicative hypothesis was found to be the most appropriate, implying that the risks associated with alcohol and tobacco multiply when the exposures occur simultaneously. The public health implications of this result and the contribution of heavy drinkers and smokers to the frequency of upper respiratory and digestive tract cancers are discussed.

Adolescent↗
PubMed1987

Epidemiology of respiratory cancers related to nickel mining and refining in New Caledonia (1978-1984).

The incidence rate of respiratory (lung and upper respiratory tract) cancer related to the nickel industry was studied in the male population of New Caledonia over a 7-year period (1978-1984). The findings show no excess incidence of lung or upper respiratory tract (larynx, pharynx, nasal cavities) cancer cases in the population of nickel workers compared with the rest of the male population in New Caledonia. This result was corroborated by a case-control study which does not indicate any particular role of hazards specific to the nickel mining and refining industry. Our findings, which may be specific for the type of ore processed in New Caledonia, must nevertheless be confirmed by extending the study to a total of 10 years (1978-1987). The incidence rate of male respiratory cancer in New Caledonia was also compared to that of cancers of this type reported in certain regions of industrialized countries (Australia, France, U.K., USA). Such findings are very similar to those observed in New Caledonia, thereby confirming a predominant role of tobacco and alcohol consumption in a territory which, despite certain characteristics of a developing country, has life-style habits similar to those of industrialized countries.

Adult↗
PubMed1986

[Retrospective evaluation of occupational exposure in epidemiologic studies. Use of the Delphi method].

A method, based on the Delphi technique, for evaluating occupational risks in a quantifiable manner was devised in the course of a case-control study on respiratory cancers in the nickel mining and refining industry in New Caledonia. There were four stages in the evaluation process: identification of eleven potential carcinogenic factors in the company during the 1930-1977 period; grouping of a limited number of work-stations; evaluation of exposure levels for the different factors for each workstation; computation of the cumulative value of exposure for each subject under study. A partial validation study shows that this kind of approach may prove useful for future occupational epidemiological studies.

Carcinogens, Environmental↗
PubMed1985

[Determinants of health in nurses].

A cross-sectional survey was carried out in 1980 among 824 nurses in 10 hospitals on the occasion of the annual checkups. The purpose was to describe the relationship between demographic and occupational characteristics and health, stressing the effects of work in shifts. Using Khi-2 tests and logistic models, the negative health effects of arduous shift work appear to be less than expected. This could be a result of the high turnover in the profession, which is characterized by a low average age and a short occupational lifetime.

Adult↗
PubMed1982

DISBAR: a program for two-group discriminant analysis on mixed variables after binary coding.

The program DISBAR is particularly adapted to medical data which often concern several measurements of different types (mixed variables) collected on patients divided into 2 groups according to a binary response variable such as survival or non-survival. DISBAR leads to a simple geometrical representation of the observations providing an easy allocation rule for a new case. The computer time required to run the program DISBAR is negligible in comparison with the one necessary to perform any other discriminant analysis of binary variables. DISBAR combines in practice computational facility with good results and easy interpretation.

Computers↗
PubMed1982

Diflunisal versus placebo for treatment of pain in general practice.

The efficacy and safety of diflunisal versus placebo in the treatment of pain were compared in a multicenter, double-blind study of 1,037 patients treated for seven days by general practitioners. A statistically significant (P less than 0.001) difference in favor of diflunisal was seen using four evaLuation criteria. The incidence of side effects was generally low with both treatments; nevertheless, the number of patients suffering at least one side effect was greater after diflunisal than after placebo (P less than 0.05). A comparison of the profile of responders to diflunisal and to placebo showed no particular pattern.

Clinical Trials as Topic↗