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[Socioeconomic status and coronary disease: theories, research methods, epidemiological evidence and the results of Italian studies].

This review covers the most important theoretic contributions and results of epidemiological research on the relationship between socio-economic status (SES) and coronary heart disease (CHD). Two major approaches have been identified: those of the British and American schools. In spite of differences in method, most of published contributions have shown social inequalities in the outcome of most degenerative disorders. Similar patterns have been detected for the CHD: the time trend declines documented in recent years in most industrialized countries has not filled in the gap of SES difference in the incidence and mortality for CHD, which even seems to have increased in the lower social classes. Moreover, an apparent paradox has been described: even though CHD is typical of welfare societies, its impact is higher in the lower social classes. Recent results of Italian studies are reported which investigated the relationship between CHD risk factors and SES in representative samples. The findings suggest the presence, in Italy, too, of social discrepancies in the prevalence of major risk factors, in both gender groups. This should be taken in consideration when preventive programmes are planned in populations or in work settings.

Adult↗
PubMed1992

A review of epidemiological methods applied in studies on laboratory animal allergy. With a discussion of the relation between prevalence and risk of an irreversible disease in a dynamic population of constant size.

The risk of developing an occupational allergic respiratory disease depends strongly on the duration of exposure. For estimating the instantaneous risk (hazard function) in a dynamic cohort, information is required for each cohort member on the time of exposure either until disease onset or until termination by leaving the job or the end of the study. However, most existing epidemiological studies on occupational allergies are cross-sectional, computing prevalences; no information on job-leavers and on their disease status is obtained. The functional dependency of prevalence on risk, as well as on the rate of leaving the job among the diseased and on the distribution of exposure duration, is described, with special attention to the sensitivity of the prevalence to differences of the rate of leaving the job. A literature review of 15 studies on laboratory animal allergy is given; none of the studies collected and reported all the information necessary for risk estimation.

Animals↗
PubMed1995

Epidemiologic methods for prospective assessment of menstrual cycle and reproductive characteristics in female semiconductor workers.

Methods were developed to assess potential adverse effects of semiconductor fabrication work in a prospective study of reproductive health. All women aged 18-44 years who worked in seven silicon-wafer fabrication sites in five companies and a frequency-matched sample of women in nonfabrication jobs were included. Among 3,480 selected for screening, 2,639 (75%) completed a self-administered questionnaire to identify women at risk of pregnancy. Among the 739 (28%) eligible women, 481 (65%) completed baseline interviews and 402 (83.6%) completed at least one menstrual cycle of follow-up by providing daily diaries and daily urine samples. Menstrual cycle characteristics were assessed from questionnaires and diaries. Urine samples were assayed for reproductive hormones to identify conceptions. The usual cycle length recalled at baseline was 28 days. The mean cycle length (MCL) recorded in diaries was 29 days, with greater dispersion than at baseline. The median of the MCL from diary data was 28 days for women reporting regular cycles at baseline but 34 days for women reporting irregular cycles at baseline, and the median standard deviation in cycle length per woman was 2.5 days and 7.5 days, respectively. The prospective method, while expensive and labor intensive, showed good compliance. Nevertheless, recall also provided reasonably accurate estimates and distinguished women with regular and irregular cycles.

Adolescent↗
PubMed1987

Epidemiologic methods for measuring prevalence of asthma.

Problems identified as associated with measuring the prevalence of asthma include the lack of an agreed definition, absence of standardization of questionnaires (both the content and the form in which questions are worded) the nonspecific nature of tests of bronchial responsiveness and the variation in the nature of asthma at different ages, seasonally and due to occupational exposures. Approaches to the resolution of these problems and outstanding questions are discussed.

Adult↗
PubMed1989

Problems of epidemiologic method in assessing the type and extent of mental illness among homeless adults.

Because the problem of homelessness has generated such attention and controversy, findings from studies of homeless populations are often received eagerly without appreciation of the significant biases inherent in surveys. Drawing on surveys of the homeless made in the 1980s, the authors review problems in sampling and in measurement of mental disorder. They suggest that within any one study researchers employ alternative sampling strategies and measures of mental disorder to facilitate comparison of results within and across studies.

Epidemiologic Methods↗
PubMed1986

Data collection, analysis, and interpretation in ambulatory care research: uses of the epidemiologic method.

In summary, in the collection, analysis, and interpretation of study data, individuals planning and analyzing the results of their own investigations or those of others must be particularly careful about the potential pitfalls that may occur. Considerable time and effort beforehand should be given to the type of study design (observational versus randomized trial) to be utilized; the scope of the investigation to be carried out, be it of a small descriptive scale or a large collaborative effort; attention to detail in the development of the data-collection instruments; and extensive training and continued monitoring of the data abstractors. Awareness of these factors should enhance data collection efforts, the quality of the collected data, and any interpretation thereof.

Ambulatory Care↗
PubMed1993

[An epidemiological method for studying the effect of elevated background radiation on the neuropsychic health of children].

The children living in 4 regions of Russia contaminated as a result of the Chernobyl catastrophe were investigated. The control group consisted of the children of 2 regions which did not undergo this influence. The investigations were made 1-3 years after the catastrophe took place. An increase of etiologically non-clear asthenic-vegetative disorders was determined in the regions of radiation contamination. They were observed mainly among the children who had light residual organic cerebral deficiency. The authors cannot exclude the impact of the psychogenic factors.

Accidents, Occupational↗
PubMed1995

Asthma and factory emissions in northern England: addressing public concern by combining geographical and epidemiological methods.

STUDY OBJECTIVE: The prevalence of asthma was assessed to investigate respiratory health effects of airborne emissions from a factory. A geographical information system allowed flexible definition of study areas in terms of their size, distance, and location in relation to the factory. The value of the approach for this type of investigation is focussed on. SETTING: The factory is located in the south western part of a small market town in County Durham. MEASUREMENTS AND MAIN RESULTS: A total of 1573 asthma cases were identified from general practitioner computerised repeat prescribing systems. Population denominators were defined from family health services authority patient registers. The area within 1 km and immediately to the north east of the factory had an age and sex standardised asthma prevalence 24% (confidence interval 4, 44%) in excess of the expected rate (p = 0.01). The increased prevalence was confined to middle aged and elderly adults living in the area between 0.5 and 1 km to the north east of the factory. CONCLUSIONS: The value of combining the skills of geographers and epidemiologists in addressing public health issues is shown, particularly through the use of geographical information systems which proved powerful and effective.

Adolescent↗
PubMed1995

[Comparison of epidemiologic methods in a case-control study of lung cancer and air pollution in Trieste, Italy].

To investigate the relationship between air pollution and histologic type of lung cancer we conducted a case-control study among deceased men in Trieste, Italy. 755 cases of lung cancer and 755 controls were identified through the local autopsy registry. Information on smoking habits, occupation and place of residence was obtained from the subject's next-of-kin. Air pollution at the residence of each subject was estimated from the average value of total particulate at the nearest monitoring station. Spatial models and logistic regression were used to evaluate the effect of residence and air pollution on LC after adjustment for age, smoking habits, likelihood of exposure to occupational carcinogens and social group. The risk of lung cancer increased with increasing level of air pollution for all types of lung cancer combined (P = 0.022), for small cell carcinoma (P = 0.016) and for large cell carcinoma (P = 0.049). Compared with inhabitants of the residential area, residents of the rural area had a relative risk (RR) of 0.6 (95% confidence interval (CI): 0.4-1.0). The RR was 1.5 (1.0-2.2) for residents of the center of the city and 1.4 (1.0-2.1) for residents of the industrial area. In the center of the city the excess risk was almost completely restricted to small cell carcinoma (RR = 2.0) and to large cell carcinoma (RR = 2.6). In the industrial area the risk was increased especially for adenocarcinoma (RR = 2.1). These results provide evidence that air pollution is a moderate risk factor for certain histologic types of lung cancer.

Adenocarcinoma↗
PubMed1975

Evaluation of a measles-smallpox vaccination campaign by a sero-epidemiologic method.

An assessment technique has been devised whereby children from 30 randomly chosen sampling sites are visited within three days of measles-smallpox vaccination and one month later. Vaccination coverage is measured at house visits and immunologic status is determined by collection of early and late blood samples on filter papers from substratified children in priority age-groups, and by looking at vaccination scars. The methodology was employed in a rural area of the Ivory Coast during the maintenance phase of a measles-smallpox vaccination program; 1762 children from 0--72 months old were inspected. Children in the target age groups, 6--24 months, had a vaccination coverage of 53.6% whereas children outside of the target group had a 10.5% coverage. Of 571 target age children, 94.6% had a measles hemagglutination-inhibition antibody titer of less than 1:10 dilution at the first visit, and were presumed susceptible to measles or vaccine. Of 247 substratified children 6--8 months, 98.3% were susceptible to measles before vaccination; 84.3% of 127 vaccinated children in this age-group sero-converted when re-tested. Of 324 children 9--24 months, 91.7% were susceptible before the campaign; 94.7% of 170 vaccinated children in this age-group converted. A positive history of prior measles or prior measles-vaccination was not a good indicator of measles serologic status. The smallpox vaccination major reaction rate was 93.2%; 91.4% of children with a recent vaccination scar sero-converted to measles vaccine. Thus, the smallpox scar read at the second visit proved the best clinical marker for determining both coverage and immunologic effectiveness of the campaign.

Age Factors↗
PubMed1994

Transmission of tuberculosis in New York City. An analysis by DNA fingerprinting and conventional epidemiologic methods.

BACKGROUND: The incidence of tuberculosis and drug resistance is increasing in the United States, but it is not clear how much of the increase is due to reactivation of latent infection and how much to recent transmission. METHODS: We performed DNA fingerprinting using restriction-fragment-length polymorphism (RFLP) analysis of at least one isolate from every patient with confirmed tuberculosis at a major hospital in the Bronx, New York, from December 1, 1989, through December 31, 1992. Medical records and census-tract data were reviewed for relevant clinical, social, and demographic data. RESULTS: Of 130 patients with tuberculosis, 104 adults (80 percent) had complete medical records and isolates whose DNA fingerprints could be evaluated. Isolates from 65 patients (62.5 percent) had unique RFLP patterns, whereas isolates from 39 patients (37.5 percent) had RFLP patterns that were identical to those of an isolate from at least 1 other study patient; the isolates in the latter group were classified into 12 clusters. Patients whose isolates were included in one of the clusters were inferred to have recently transmitted disease. Independent risk factors for having a clustered isolate included seropositivity for the human immunodeficiency virus (HIV) (odds ratio for Hispanic patients, 4.31; P = 0.02; for non-Hispanic patients, 3.12; P = 0.07), Hispanic ethnicity combined with HIV seronegativity (odds ratio, 5.13; P = 0.05), infection with drug-resistant tuberculosis (odds ratio, 4.52; P = 0.005), and younger age (odds ratio, 1.59; P = 0.02). Residence in sections of the Bronx with a median household income below $20,000 was also associated with having a clustered isolate (odds ratio, 3.22; P = 0.04). CONCLUSIONS: In the inner-city community we studied, recently transmitted tuberculosis accounts for approximately 40 percent of the incident cases and almost two thirds of drug-resistant cases. Recent transmission of tuberculosis, and not only reactivation of latent disease, contributes substantially to the increase in tuberculosis.

AIDS-Related Opportunistic Infections↗