摘要:

The Indoor Air and Children's Health Study is a prospective cohort study of the relation between indoor air pollution and lower respiratory illness (LRI) during the first 2 years of life. Information on family and household characteristics was obtained from a health maintenance organization for 1,424 infants enrolled at birth. Data on LRI were abstracted from medical records. The incidence of all LRI was 48.4 per 100 child-years. Wheezing-associated respiratory illness (WARI)/ asthma was the most common specific LRI, with an incidence of 11.5 per 100 child-years. Total LRI incidence was lowest during the first 6 months of life. Girls had lower incidence than boys [rate ratio (RR) = 0.8; 95% confidence interval (CI) = 0.7–0.8)]. With the exception of croup, all LRI were most common during February and March. These results are comparable with those of other prospective studies. Consistent with other studies, self-reported maternal smoking demonstrated an RR of 1.5 (95% CI = 1.2–1.8) for total LRI, but the association varied for specific LRIs from 2.3 (95% CI = 1.5–3.0) for WARI/asthma to 1.0 (95% CI = 0.7–1.6) for bronchitis.

ISSN:1044-3983    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Because experimental and epidemiologic evidence indicates that the colon is particularly sensitive to stress, and because work conditions contribute to an individual's stress experience, we examined the relation of both job stress (defined in terms of perceived job demand and job control) and job social support to the risk of colon cancer in a large population-based case-control study (744 pairs) in Los Angeles. Controls were individually matched to cases on age, sex, and neighborhood.For jobs held 5 years before, participants in the lowest tertile of job control had a slightly increased risk when compared with those in the highest tertile (multivariate adjusted odds ratio = 1.3; 95% confidence interval = 1.0–1.6), but there was no evidence of a trend. Lower levels of job social support were associated with a decreased risk of colon cancer (odds ratio = 0.6 for lowest vs highest tertile; 95% confidence interval = 0.4–1.0). We saw no effect for job demand. The effect of job control appeared to be independent of the level of job demand. We found no consistent pattern of effects associated with jobs held 30 years before. These findings indicate that if job stress, as reflected by perceived job demand or control, is a determinant of colon cancer, it is probably not a strong one.

ISSN:1044-3983    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Vulvovaginal candidiasis (VVC) is a common inflammatory condition caused by vaginal overgrowth of Candida albicans. Typical symptoms include pruritus and discharge. To test the association between several hypothesized risk factors and VVC, we conducted a case-control study among university students, with both clinic and population controls. Symptomatic, culture-proven VVC was associated with receptive oral sex twice or more in the previous 2 weeks [vs not at all, odds ratio (OR) = 3.5; 95% confidence interval (CI) = 1.7–7.0]; oral contraceptive use (OR = 1.8; 95% CI = 0.95–3.6); spermicide use (OR = 3.3; 95% CI = 1.6–6.8); a prior diagnosis of VVC in the previous year (OR = 3.0; 95% CI = 1.5–5.9); and black (OR = 6.8; 95% CI = 3.1–15) and “other” race (OR = 2.2; 95% CI = 1.0–4.6). Estimates are from a cases vs population controls logistic regression model including all five variables; results for cases vs clinic controls were similar. After adjusting for these factors, many other hypothesized risk factors, such as antibiotic use, menstrual hygiene practices, and vaginal intercourse, had little association with VVC.

ISSN:1044-3983    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

To examine the association between parental occupation and spina bifida in offspring, we conducted a multicenter case-referent study in the Netherlands. Cases were children with spina bifida aperta from nine different hospitals throughout the country; the referent group comprised population-based referents who were randomly drawn from municipal birth registries. All children were born between 1980 and 1992. We collected data using postal questionnaires for both parents with questions about occupational title, industry, daily occupational activities, and a number of potential confounders. We were able to include 353 cases and 1,329 referents in the analyses. We found increased risks for maternal agricultural occupations [odds ratio (OR) = 5.6; 95% confidence interval (CI) = 1.8–17.81] and for cleaning women (OR = 1.9; 95% CI = 0.9–3.9). For the fathers, we saw increased odds ratios for welders (OR = 2.1; 95% CI = 0.6–7.0) and transport workers (OR = 1.4; 95% CI = 0.9–2.1).

ISSN:1044-3983    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Spontaneous and induced abortions have been suggested to increase the risk of intrapartum infection in the following pregnancy. We conducted a case-control study using data from the Washington State Birth Registry for the years 1989–1991. The study population comprised women delivering a singleton livebirth. A case was defined by the presence of intrapartum fever (N = 2,550). Controls (1:3) were selected from the remaining births (N = 7,326). We calculated Mantel-Haenszel summary odds ratios by stratified analysis. We evaluated the validity of intrapartum fever recorded on the birth certificate using data from an ongoing case-control study on clinical amnionitis in Washington State. We found intrapartum fever to be highly specific (0.98) and moderately sensitive (0.57) for a diagnosis of clinical amnionitis. We saw no increased risk of intrapartum fever after a fetal loss or termination when using women with no prior pregnancy as the reference group. On the other hand, we found a threefold elevated risk for both induced and spontaneous abortion when using women with a prior livebirth as the reference group. Our findings indicate that an abortion in a woman's first pregnancy does not have the same protective effect of lowering the risk for intrapartum infection in the following pregnancy as does a livebirth.

ISSN:1044-3983    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Weighted kappa coefficients are commonly used to quantify inter- or intra-rater reliability or test-retest reliability of ordinal ratings in clinical and epidemiologic applications. In this paper, we assess the dependence of weighted kappa coefficients on the number of categories and the type of weighting scheme, which vary between applications. The most commonly used weights are weights that are proportional to the deviation of individual ratings (“linear weights”) or to the square of the deviation of individual ratings (“quadratic weights”). Quadratically weighted kappa coefficients are equivalent to the intraclass correlation coefficient and to the product-moment correlation coefficient under certain conditions. We illustrate that an increase of quadratically weighted kappa coefficients with the number of categories is expected under a broad variety of conditions, whereas linearly weighted kappa coefficients appear to be less sensitive to the number of categories. Number of categories and type of weighting scheme therefore require careful consideration in the interpretation of weighted kappa coefficients.

ISSN:1044-3983    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

We examined the association of nonsteroidal antiinflammatory drugs and breast cancer risk in a case-control study of 511 breast cancer patients and 1,534 population control subjects. The relative risk of breast cancer was reduced in women using these compounds at least 3 times per week for ≥1 year [odds ratio (OR) = 0.66; 95% confidence interval (CI) = 0.52–0.831. Odds ratios were similar for use of ibuprofen (0.57) or aspirin per se (0.69). Breast cancer risk declined with increasing exposure, and the greatest risk reduction (40%; odds ratio = 0.60; 95% CI = 0.40–0.91) occurred at the highest level of use (daily intake for ≥5 years). These results indicate that nonsteroidal antiinflammatory drugs may have chemopreventive potential against the development of breast cancer.

ISSN:1044-3983    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

We examined the relation between spontaneous abortion and polymorphisms in two genes, glutathione S-transferase (GSTMI) and N-acetyltransferase (NAT2), which are involved in the metabolism of xenobiotics. In a case-control study of 29 women, we found that, among women with the GSTMI null genotype, the odds ratio (OR) was 3.1 [95% confidence interval (Cl) = 1.3–7.0]. There was less evidence of a relation with NAT2 [Mantel-Haenszel adjusted OR (ORMH) = 1.4; 95% CI = 0.45–4.3]. We sought to replicate the GSTMI finding in an independent case-control study from New York involving 89 cases. We found an inverse association (OR = 0.8; 95% CI = 0.4–2.4). Taken together, these data provide little evidence of an association between GSTMI or NAT2 genotype and risk of spontaneous abortion.

ISSN:1044-3983    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:1044-3983    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:1044-3983    

出版商:OVID    

年代:1996

数据来源: OVID