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Biomedical subjects

L Bisanti

Publications and source records attributed to L Bisanti.

At least 37 records · Page 2Linked to original sources
PubMed1997

The performance of several indicators in detecting recall bias. European Study Group on Infertility and Subfecundity.

Self-reported exposure data are vulnerable to differential recall, which threatens the internal validity and thus the credibility of the study. When a proxy measure of the exposure of interest is available, it may be possible to check for the presence of recall bias due to misclassification of the exposure information. We present a number of indicators of recall bias for case-control studies, and we describe their behavior by means of computer simulations. The indicators are all based upon a comparison between self-reported exposure data and data on job titles grouped into exposure-specific matrices. The indicators are based upon the assumption that job titles are reported without differential misclassification for cases as well as controls. We also assume that exposure data are reported with the same accuracy by workers in different jobs. Under these assumptions, the proposed indicators will provide valuable-although not conclusive-signs of recall bias. The principles elaborated in this paper can be applied to other situations in which self-reported exposure data are used.

Bias↗
PubMed1997

Urban air pollution and emergency admissions for asthma in four European cities: the APHEA Project.

BACKGROUND: A study was undertaken to assess the combined association between urban air pollution and emergency admissions for asthma during the years 1986-92 in Barcelona, Helsinki, Paris and London. METHODS: Daily counts were made of asthma admissions and visits to the emergency room in adults (age range 15-64 years) and children (< 15 years). Covariates were short term fluctuations in temperature and humidity, viral epidemics, day of the week effects, and seasonal and secular trends. Estimates from all the cities were obtained for the entire period and separately by warm or cold seasons using Poisson time-series regression models. Combined associations were estimated using meta-analysis techniques. RESULTS: Daily admissions for asthma in adults increased significantly with increasing ambient levels of nitrogen dioxide (NO2) (relative risk (RR) per 50 micrograms/m3 increase 1.029, 95% CI 1.003 to 1.055) and non-significantly with particles measured as black smoke (RR 1.021, 95% CI 0.985 to 1.059). The association between asthma admissions and ozone (O3) was heterogeneous among cities. In children, daily admissions increased significantly with sulphur dioxide (SO2) (RR 1.075, 95% CI 1.026 to 1.126) and non-significantly with black smoke (RR 1.030, 95% CI 0.979 to 1.084) and NO2, though the latter only in cold seasons (RR 1.080, 95% CI 1.025 to 1.140). No association was observed for O3. The associations between asthma admissions and NO2 in adults and SO2 in children were independent of black smoke. CONCLUSIONS: The evidence of an association between air pollution at current urban levels and emergency room visits for asthma has been extended to Europe. In addition to particles, NO2 and SO2--by themselves or as a constituent of a pollution mixture--may be important in asthma exacerbations in European cities.

Adolescent↗
PubMed1997

Does moderate alcohol intake reduce fecundability? A European multicenter study on infertility and subfecundity. European Study Group on Infertility and Subfecundity.

BACKGROUND AND AIM: There are plausible reasons to suggest that heavy alcohol consumption reduces male as well as female fecundability, but only a few epidemiological studies have addressed this issue, and results concerning the effect of a moderate intake are equivocal. The present studies were designed to examine the association between male and female alcohol intake at the start of the waiting time to a planned pregnancy. METHODS: Two types of studies were used-a population-based study of randomly selected women between 25 and 44 years in the different European countries from census registers and electoral rolls, and a pregnancy-based study of consecutive pregnant women (at least 20 weeks pregnant) recruited during prenatal care encounters. More than 4000 couples were included in each study, and 10 different regions in Europe took part in the data collection. Data were collected through personal interviews in all population-based samples and in all but four regions of the pregnancy study. RESULTS: The results showed no strong nor coherent association between alcohol intake and subfecundity. CONCLUSIONS: Should any causal effect be present it is restricted to females with a high intake of alcohol within the range of normal consumption reported in European countries.

Adult↗
PubMed1996

Shift work and subfecundity: a European multicenter study. European Study Group on Infertility and Subfecundity.

Shift work has been associated with various unfavorable pregnancy outcomes (ie, pregnancy loss, spontaneous abortion, low birth weight, etc). The suggested underlying mechanism is the interference of shift work with the circadian regulation of human metabolism and, in particular, with the temporal pattern of endocrine function. To analyze the effect of shift work on fecundity, the Time of Unprotected Intercourses (TUI) has been measured in couples recruited in the European Studies on Infertility and Subfecundity, which were undertaken in seven European countries. A low (odds ratio < 2.0) but consistent excess risk of subfecundity (TUI > or = 9.4 months) has been observed both in a representative sample of the general population of women in reproductive age and in a sample of pregnant women or women who had just given birth. The excess risk was also consistently evident both in the subsample of the first pregnancies and in the subsample of the most recent pregnancies. Only the exposure of women to shift work seemed to affect a couple's fecundity; men working shift work did not modify the fecundity pattern of their own couples. No specific job title among shift workers concentrated the risk of subfecundity. No association of menstrual disorders with shift work was identified. Even though residual confounding could partly account for the results and the fact that a plausible biological explanation of the claimed effect is still lacking, data from this study are in favor of an association between shift work and prolonged waiting time to pregnancy.

Adult↗
PubMed1996

Short term effects of urban air pollution on respiratory health in Milan, Italy, 1980-89.

STUDY OBJECTIVE: To investigate the association between daily urban air pollution and acute effects on respiratory health. STUDY DESIGN: Time series analysis following the procedure defined in the APHEA protocol. SETTING: City of Milan, Italy, from 1980-89. Two air pollutants, total suspended particulates (TSP) and sulphur dioxide (SO2), and two health outcomes, deaths and hospital admissions were considered. The last was analysed according to two age groups. SUBJECTS: Daily deaths and general hospital admissions for respiratory causes in residents who died in Milan or were admitted to local hospitals in that city. MAIN RESULTS: There was an increased risk of respiratory death and of hospital admission associated with increased concentrations of SO2 and TSP. The relative risks were similar for both pollutants, and were higher for respiratory deaths than for hospital admissions. No changes in relation to season were seen in the SO2 effect on respiratory deaths, but there was a suggestion of a higher effect on hospital admissions in the cool months. The seasonal pattern of the TSP effect was inconsistent: for mortality it was higher in the warm period while for hospital admissions it seemed to be higher in the cool months. This last result might be due to chance, although some role could have been played by the hospital admission data on all general admissions for respiratory causes (ICD-9: 460-519) as these are a much less specific end point. CONCLUSION: In Milan, a positive association was found between the daily SO2 or TSP concentrations and the number of deaths or hospital admissions for respiratory causes. This confirms results from other European and North American cities.

Acute Disease↗
PubMed1995

Are seasonal preferences in pregnancy planning a source of bias in studies of seasonal variation in reproductive outcomes? The European Study Group on Infertility and Subfecundity.

Seasonal variation in reproductive failures is expected, as many of the putative causes change over the seasons. Many studies have documented such seasonal variation in reproductive failures, but none has addressed the potential source of bias related to seasonal planning of pregnancies. Our aim was to quantify this bias under realistic assumptions. We used data from the European Study of Infertility and Subfecundity, which is a study based upon representative samples of women age 25-44 years in different parts of Europe. Data on pregnancy planning stem from personal interviews. Altogether, we analyzed 4,731 pregnancies. Results show that pregnancy planning is not evenly distributed over the seasons, with summer the preferred time for starting pregnancy. The most fecund will conceive within the preferred time, but those who are subfecund may not succeed until later. Since subfecund women have a higher risk of some reproductive failures (spontaneous abortions, for example), the seasonal planning differences could in themselves lead to seasonal variations in reproductive failures. A simulation model shows that bias related to differential pregnancy planning is likely to have only a small impact under the present conditions in Europe.

Abortion, Spontaneous↗
PubMed1995

[Air pollution and daily mortality among Milan residents, 1980-89. Preliminary results].

Short term effects of air pollutant levels on daily mortality were studied, using time series approach, in Milan from the year 1980 to 1989. The Poisson regression with autocorrelated residuals was applied. This paper reports preliminary results of the analyses on the association between total daily number of deaths and the 24h mean concentrations, on the same day, for two air pollutants: sulphur dioxide and total suspended particulate. A positive and curvilinear relation (with a logarithmic shape) has been found between total daily mortality and concentration levels for each pollutant. This result confirm a steeper increase in mortality at low concentrations, lower than the international standards in use at the moment.

Air Pollutants↗
PubMed1993

Cancer mortality in ethylene oxide workers.

A cohort of 1971 chemical workers licensed to handle ethylene oxide was followed up retrospectively from 1940 to 1984 and the vital status of each subject was ascertained. No quantitative information on exposure was available and therefore cohort members were considered as presumably exposed to ethylene oxide. The cohort comprised 637 subjects allowed to handle only ethylene oxide and 1334 subjects who obtained a licence valid for ethylene oxide as well as other toxic gases. Potential confounding arising from the exposure to these other chemical agents was taken into consideration. Causes of death were found from death certificates and comparisons of mortality were made with the general population of the region where cohort members were resident. Seventy six deaths were reported whereas 98.8 were expected; the difference was statistically significant. The number of malignancies for any site exceeded the expected number (standardised mortality ratio (SMR) = 130; 43 observed deaths; 95% confidence interval (95% CI) 94-175) and approached statistical significance. For all considered cancer sites the SMRs were higher than 100 but the excess was only significant (p < 0.05, two sided test) for lymphosarcoma and reticulosarcoma (International Classification of Diseases--9th revision (ICD-9) = 200; SMR = 682; four observed deaths; 95% CI 186-1745). The excess of cases for all cancers of haematopoietic tissue (ICD-9 = 200-208) also approached statistical significance (SMR = 250; six observed deaths; 95% CI 91-544). Focusing the analysis on the subcohort of the ethylene oxide only licensed workers, who are likely to have experienced a more severe exposure to this gas, it became evident that all but one of the observed cases of haematopoietic tissue cancers in the cohort were confined to this subgroup, enhancing the relevant SMR to 700 (95% CI 237-1637) and the SMR of lymphosarcoma and reticulosarcoma to 1693 (95% CI 349-4953).

Adult↗
PubMed1989

Prevalence of HBeAg, anti-HBe serological markers and HBV-DNA in asymptomatic carriers in Ethiopia.

Data on the distribution of HBV-DNA and other serological markers of hepatitis B virus infection in a population of asymptomatic carriers in Ethiopia are reported. As compared to data from other countries of similar or lower levels of endemicity, it has been found that HBV-DNA prevalence and its correlation with HBeAg/anti-HBe status is similar to that of northern Europe. HBV-DNA is present in 84% of HBe Ag-positive sera but in only 4% of anti-HBe-positive sera, where the lowest concentration of DNA (less than 5 pgr/20 microliters) was found. The trend of increasing prevalence of serological markers with age seems to indicate a considerable horizontal transmission still present in this age range (18-30). In keeping with data of other authors a 3% of HBV-DNA positivity in anti HBc only positive sera was found. No regional or ethnical differences of HBV-DNA positive sera across the country were observed. There is also no evidence of any correlation between HBV-DNA prevalence and HBsAg subtypes ad and ay.

Adolescent↗
PubMed1988

Ethiopian National Hepatitis B Study.

A nationwide seroepidemiological study of hepatitis B markers prevalence was conducted in Ethiopia on 5,270 young males from all regions of the country. Overall prevalence rates were 10.8% for HBsAg and 73.3% for "at least one marker positive"; a remarkable geographical and ethnic variability of marker prevalence was observed, reflecting the wide differences existing in Ethiopia in sociocultural environment and activities such as tribal practices and traditional surgery. Sexual practices and medical exposure also play some role as determinants of hepatitis B marker prevalence in Ethiopia. General preventive measures, with particular reference to health education, by affecting incriminating habits and practices could have some impact on infection rates in Ethiopia, in the absence of a vaccination strategy presently unrealistic in this region of the world.

Adolescent↗
PubMed1988

Delta hepatitis virus infection in Ethiopia.

The results of Hepatitis Delta virus (HDV) antibody determinations carried on 566 HBsAg positive serum samples from a population of 5270 Ethiopian military recruits are reported. The prevalence of anti-HDV among apparently healthy HBsAg carriers was 5.8%. The prevalence increases with age within the available range (18-30 years). Differences might exist by area of origin and ethnic groups. The distributions of HBV markers was similar in anti HDV positive and anti HDV negative individuals, possibly due to the relatively young age of the population and/or the hyperendemic condition of the area.

Adolescent↗
PubMed1988

Hepatitis B infections in the Arsi region of Ethiopia.

In a sample of inhabitants of the Arsi region of Ethiopia prevalence of hepatitis B is around 80% in the age group 20-24. In addition to age, sex and size of family, exposure to tribal practices is a determinant of seropositivity in this group accounting for as much as 20% of the total burden of the infection. Waiting for a mass vaccination campaign, presently unrealistic in this area of the world, health education, as part of a comprehensive primary health care program, has to be considered as a potentially effective preventive tool.

Adult↗
PubMed1980

Experiences from the accident of Seveso.

Provisional data on selected sanitary events which took place at Seveso after July 10 1976 are reported. 187 cases of chloracne, mostly in children, were detected, 50 just after the accident, the others within a year. Most polluted area (zone A) provided almost all "early" and most severe cases, but the territorial distribution of chloracne prevalence rates showed some inconsistencies with the soil TCDD pollution map; interpretations for such findings are discussed. Thirty-eight birth defects were detected in 1977 (none in zones A and B), more than in previous years, but still less than expected in a well controlled "normal" population: no clustering around a given type was observed. Spontaneous abortions, evaluated both as abortion rates and as pregnancy loss rates, showed scattered and statistically non-significant variations, inconsistent with the pollution map. No differences in birth and death rates compared to surrounding areas were observed. Data on ad hoc cytogenetic, neurological and immunological surveys are commented. Limitations of the presently available data are discussed and further research lines are anticipated.

Abnormalities, Drug-Induced↗