Migration and child immunization in Nigeria: individual- and community-level contexts

Background  

Vaccine-preventable diseases are responsible for severe rates of morbidity and mortality in Africa. Despite the availability of appropriate vaccines for routine use on infants, vaccine-preventable diseases are highly endemic throughout sub-Saharan Africa. Widespread disparities in the coverage of immunization programmes persist between and within rural and urban areas, regions and communities in Nigeria. This study assessed the individual- and community-level explanatory factors associated with child immunization differentials between migrant and non-migrant groups.     

Socioeconomic and occupational risk factors for pancreatic cancer: a cohort study in Sweden

OBJECTIVE: The objective of this study was to examine the associations between socioeconomic/occupational factors and pancreatic cancer. METHODS: The Swedish Family-Cancer Database was used to calculate standardized incidence ratios for different social classes and occupational groups. Lung cancer risks were also determined. The reference group was all the economically active population. RESULTS: Farmers were at a decreased risk of pancreatic cancer. A slightly increased risk of pancreatic cancer, independent of lung cancer, was observed for male professionals and administrators and managers. For women, increased risks were observed for cooks and stewards, and glass, ceramic, and tile workers. CONCLUSIONS: The results show that socioeconomic/occupational factors play a small role in the etiology of pancreatic cancer. In addition to smoking, physical inactivity and obesity may contribute to the observed differences.     

Socioeconomic factors and race in breast cancer recurrence and survival.

The relation of breast cancer recurrence and overall survival to age, level of estrogen receptors, number of positive lymph nodes, obesity, race, socioeconomic status, and tumor size at the time of diagnosis was considered for 1,392 breast cancer patients (253 black, 1,132 white, and 7 of other races) entered into two multi-institutional prospective clinical trials. Baseline for the first trial was 1974-1979, and that for the second was 1980-1985; follow-up for this report ended in August 1990. Univariately, all factors except age and obesity were significantly related to disease-free survival, and all except age were significantly related to overall survival. A multivariate analysis using Cox's proportional hazards model indicated that a greater number of positive lymph nodes, a larger tumor diameter, lower socioeconomic status, and negative estrogen receptors were significantly related to shorter disease-free survival. After adjustment for socioeconomic status, race ceased to be a significant indicator of either disease-free survival or overall survival. Patients of either race who are of a lower socioeconomic status are more likely to have a recurrence and to die of breast cancer.     

Socioeconomic risk factors for bacterial gastrointestinal infections

BACKGROUND: Bacterial gastrointestinal infections cause considerable morbidity in industrialized countries, but little is known about socioeconomic factors affecting the risk of infection. METHODS: By linkage among 3 national registers, we followed the entire population of Denmark (5.3 million people) from 1993 to 2004 for the occurrence of laboratory-confirmed bacterial gastrointestinal infections. Using Poisson regression analyses, incidence rate ratios (IRRs) were estimated for the major groups of bacteria in different socioeconomic strata, focusing on income group, level of education, marital status, number of children in the household, and country of birth. RESULTS: Associations with socioeconomic variables varied by type of bacterium. High-income groups had increased risks of infection with Campylobacter, Shigella, and Salmonella Enteritidis, and education was positively associated with increased risk of infection with Campylobacter and Shigella. Married persons were generally at higher risk than single persons, but adults with children had lower risks compared with adults without children. Foreign-born persons generally had lower risks, whereas Danish-born persons with foreign-born parents were at reduced risk of infection with the pork-associated bacterium Yersinia (IRR = 0.33; 95% confidence interval 0.25-0.42), but increased risk with Shigella (5.7; 4.8-6.1), Salmonella, and Shiga toxin-producing Escherichia coli. CONCLUSIONS: The findings suggest that risk of infection is not primarily associated with poverty, but rather with increasing socioeconomic status. Risk of infection also varies with cultural background. Observed differences may be explained by differences in diet and travel activity, although they may also in part reflect differential probabilities of diagnostic reporting.     

Synergism between radiation and other risk factors for breast cancer

The question of whether the risk of radiation-induced breast cancer is additive or multiplicative (synergistic) with other risk factors for breast cancer has important implications for determining optimal guidelines for mammographic screening. Data from a follow-up study of 571 women given X-ray therapy for acute postpartum mastitis in Rochester, New York, and 993 control women were analyzed to examine this question. No synergism was found between breast irradiation and family history of breast cancer, late parity, oral contraceptive use, menopausal hormone use, or a composite of ovarian-related factors. Results indicated that women with a history of breast irradiation who develop benign breast disease, particularly cystic disease, are at high risk for breast cancer and should be carefully monitored. Women who were irradiated at the time of their first childbirth are also at especially high risk for breast cancer.     

Socioeconomic status and survival for breast and cervical cancer

This paper considers the association between socioeconomic status (SES) and survival from breast and cervical cancers, two major health problems for women. For both cancers, lower SES women appear to have poorer survival. Factors which may account for this are discussed, including biological and nutritional factors. Major emphasis is placed on early detection since this appears to play a critical role in the survival differential. Factors which act as barriers to early detection among poor women are considered, including those related both to the health behaviors of the poor and to the health care system available to the poor.     

Relationship between risk factors for breast cancer and hormonal status

A total of 512 breast cancer patients and 540 controls were compared to examine the risk factors for different categories of breast cancer as defined by age, menopausal status and estrogen receptor (ER) tumor status. Significant differences were found by menopausal status, for age at first birth and age at menarche for all women, and for age at first birth and family history for women between 45 and 54 years old. No significant differences were found with ER status alone; however there was a significant difference between ER status and body weight in premenopausal women; the above significant differences with menopausal status were not found when stratified by ER tumour status. These findings support the hypothesis for aetiological differences for pre- and postmenopausal breast cancer and suggest that ER tumour status may influence the risk associated with body weight.     

Dietary factors and the risk of breast cancer

We evaluated the risk of breast cancer in relation to the frequency of consumption of a few selected dietary items. Data were used from a case‐control study of 1,108 histologically confirmed breast cancer patients and 1,281 control subjects who were in the hospital for acute conditions unrelated to any of the established or suspected risk factors for breast cancer. Moderately elevated risk estimates were associated with higher levels of fat consumption in seasonings [butter, margarine, and oil, relative risk (RR) = 1.34, 95% confidence interval (CI) = 1.06–1.71] and meat (RR = 1.36, 95% CI = 1.12–1.65), whereas a reduced risk (RR = 0.42, 95% CI = 0.34–0.51) was associated with a more frequent green vegetable consumption. It was not possible to show that these associations were incidental, because allowance for several identified potential confounding factors, including the major identified or potential risk factors for breast cancer, did not materially modify the risk estimates. Further, no appreciable interaction emerged with age or menopausal status, because the diet‐related risk estimates were similar in pre‐ or postmenopausal women. However, the implications of these findings in terms of specific micronutrients (e.g., retinal or β‐carotene) and biological correlates are still unclear. Alcohol consumption was significantly greater among breast cancer cases, with a multivariate risk estimate of 2.92 for the highest level. Thus, the present findings confirm that various aspects of diet may influence the risk of breast cancer, although the small amount of available knowledge does introduce serious uncertainties in any discussion of the potential implications in terms of prevention on a public health scale.     

Dietary factors and the risk of breast cancer

We evaluated the risk of breast cancer in relation to the frequency of consumption of a few selected dietary items. Data were used from a case-control study of 1,108 histologically confirmed breast cancer patients and 1,281 control subjects who were in the hospital for acute conditions unrelated to any of the established or suspected risk factors for breast cancer. Moderately elevated risk estimates were associated with higher levels of fat consumption in seasonings [butter, margarine, and oil, relative risk (RR) = 1.34, 95% confidence interval (CI) = 1.06-1.71] and meat (RR = 1.36, 95% CI = 1.12-1.65), whereas a reduced risk (RR = 0.42, 95% CI = 0.34-0.51) was associated with a more frequent green vegetable consumption. It was not possible to show that these associations were incidental, because allowance for several identified potential confounding factors, including the major identified or potential risk factors for breast cancer, did not materially modify the risk estimates. Further, no appreciable interaction emerged with age or menopausal status, because the diet-related risk estimates were similar in pre- or postmenopausal women. However, the implications of these findings in terms of specific micronutrients (e.g., retinol or beta-carotene) and biological correlates are still unclear. Alcohol consumption was significantly greater among breast cancer cases, with a multivariate risk estimate of 2.92 for the highest level. Thus, the present findings confirm that various aspects of diet may influence the risk of breast cancer, although the small amount of available knowledge does introduce serious uncertainties in any discussion of the potential implications in terms of prevention on a public health scale.     

雌,孕激素受体状态与乳腺癌危险因素的关系

目的 探讨雌、孕激素受体（ＥＰ、ＰＲ）状态不同的乳腺癌是否在发病危险因素方面有差异。方法 １９９６年３月～１９９８年１月间在大连医科大学附属一、二院进行了一次病例对照研究。结果 病例同受体状态分析提示在年龄上ＥＲ组间有差别;ＰＲ组间各因素都没有差异。病例对照间单因素及多因素Ｌｏｇｉｓｔｉｃ回归分析发现按ＥＲ状态分层,唯有ＢＭＩ、活产胎数、哺地ＥＲ（＋）及ＥＲ（－）乳腺癌危险性的作用不同,按ＰＲ状态     

Socioeconomic status and breast cancer in Denmark

BACKGROUND: Breast cancer is the most frequent cancer in women and the incidence has increased over time. Our objectives were to study: (1) the socioeconomic differences in breast cancer incidence and mortality in Denmark, (2) how different socioeconomic groups have contributed to the increasing incidence, (3) whether the diverging trend between breast cancer incidence and mortality reflects different socioeconomic distributions of breast cancer cases and breast cancer deaths, and (4) to compare measures of socioeconomic status based on own and spouses' occupation, respectively. We addressed these questions by studying the socioeconomic distribution of breast cancer incidence and breast cancer mortality in Danish women during the last 25 years. METHODS: In all 1 402 225 women in Denmark were individually followed up for death, emigration, and incident breast cancer in 1970-1995. Of the 1 402 225 women included in the study, 730 549 were economically active in 1970, and 480 379 women were both married and economically active. Socioeconomic status was assessed based on the occupation in 1970. RESULTS: For all women classified by their own socioeconomic group, the standardized incidence (SIR) and the standardized mortality ratios (SMR) were highest in academics (SIR = 1.39, SMR = 1.29), and lowest in women in agriculture (SIR = 0.77, SMR = 0.75). For married, economically active women classified by their own socioeconomic group the SIR and SMR were highest in academics (SIR = 1.40, SMR = 1.44) and lowest in women in agriculture (SIR = 0.76, SMR = 0.76). Classified by their husbands' socioeconomic group, the SIR and SMR were highest in women married to academics (SIR = 1.21, SMR = 1.16) and lowest in women married to men in agriculture (SIR = 0.79, SMR = 0.79). From 1970 to 1995, the risk of developing breast cancer increased by 38% in women aged 50-64. All social groups contributed to this increase, the increase being 45% in unskilled workers, and 26% in academics. CONCLUSION: During the last quarter of the 20th century academics had the highest risk of breast cancer in Denmark. The size of the social gradient in breast cancer occurrence depended on the measure used. The time trends in social distribution will result in breast cancer becoming more frequent.     

Socioeconomic risk factors for asthma in Chilean young adults

OBJECTIVES: We studied the association between socioeconomic status (SES) and asthma symptoms, severity of asthma, atopy, and bronchial hyperresponsiveness (BHR) to methacholine. METHODS: We studied 1232 men and women born between 1974 and 1978 in a semirural area of Chile. We assessed asthma symptoms with a standardized questionnaire, atopy with a skin-prick test to 8 allergens, and BHR to methacholine with the tidal breathing method. SES was derived from several indicators: education, occupation, completion of a welfare form, belongings, housing, number of siblings, and overcrowding. RESULTS: Those with fewer belongings had more asthma symptoms. Those who had higher education and those who owned cars had fewer asthma symptoms and BHR. Overcrowding was negatively related to atopy, atopy with asthma symptoms, and BHR. Higher education and noncompletion of a welfare form were risk factors for atopy. CONCLUSION: The strength and direction of the association between asthma and SES depended on what definition of asthma was analyzed. Asthma symptoms were more common among poor people. There was some support for the hygiene hypothesis, as overcrowding was associated with less wheezing with atopy, less atopy, and less BHR.     

Regional inequalities in under-5 mortality in Nigeria: a population-based analysis of individual- and community-level determinants

Background  

Regions with geographically diverse ecology and socioeconomic circumstances may have different disease exposures and child health outcomes. This study assessed variations in the risks of death in children under age 5 across regions of Nigeria and determined characteristics at the individual and community levels that explain possible variations among regions.     

Regional inequalities in under-5 mortality in Nigeria: a population-based analysis of individual- and community-level determinants

Background

Verbal autopsy (VA) is used to estimate the causes of death in areas with incomplete vital registration systems. The King and Lu method (KL) for direct estimation of cause-specific mortality fractions (CSMFs) from VA studies is an analysis technique that estimates CSMFs in a population without predicting individual-level cause of death as an intermediate step. In previous studies, KL has shown promise as an alternative to physician-certified verbal autopsy (PCVA). However, it has previously been impossible to validate KL with a large dataset of VAs for which the underlying cause of death is known to meet rigorous clinical diagnostic criteria.

Methods

We applied the KL method to adult, child, and neonatal VA datasets from the Population Health Metrics Research Consortium gold standard verbal autopsy validation study, a multisite sample of 12,542 VAs where gold standard cause of death was established using strict clinical diagnostic criteria. To emulate real-world populations with varying CSMFs, we evaluated the KL estimations for 500 different test datasets of varying cause distribution. We assessed the quality of these estimates in terms of CSMF accuracy as well as linear regression and compared this with the results of PCVA.

Results

KL performance is similar to PCVA in terms of CSMF accuracy, attaining values of 0.669, 0.698, and 0.795 for adult, child, and neonatal age groups, respectively, when health care experience (HCE) items were included. We found that the length of the cause list has a dramatic effect on KL estimation quality, with CSMF accuracy decreasing substantially as the length of the cause list increases. We found that KL is not reliant on HCE the way PCVA is, and without HCE, KL outperforms PCVA for all age groups.

Conclusions

Like all computer methods for VA analysis, KL is faster and cheaper than PCVA. Since it is a direct estimation technique, though, it does not produce individual-level predictions. KL estimates are of similar quality to PCVA and slightly better in most cases. Compared to other recently developed methods, however, KL would only be the preferred technique when the cause list is short and individual-level predictions are not needed.     

Occupational risk factors for breast cancer among women in Shanghai

Although female breast cancer rates are lower in China than in Western countries, rates have been rising rapidly in China. This increase may be due to changes in established breast cancer risk factors, but it is possible that exposure to occupational and environmental carcinogens in Shanghai also have contributed to the rise in incidence. We used data collected by the Shanghai Cancer Registry and the Chinese Third National Census to study the risk of breast cancer by occupation and by occupational exposures. Standardized incidence ratios (SIRs) were used to compare observed cases to expected numbers of cases, based on the incidence rates for Shanghai and the number of women in each occupation according to the 1982 census. Statistically elevated SIRs for breast cancer were seen for a number of professional occupational categories, with the greatest risk seen among scientific research workers (SIR = 3.3). Administrative clerks, political and security personnel, and makers of rubber and plastics products also had significant excesses. Significant deficits of risk were seen for the categories of production and related workers, construction workers, and transportation equipment operators. For specific occupations, the highest SIRs were observed among doctors of Chinese-Western medicine (SIR = 14.7, 95% CI = 5.9–30.3) and doctors of Chinese medicine (SIR = 7.2, 95% CI = 4.4–11.4). We also found excesses among teachers at each level of education, librarians, clerical workers, electrical and electronic engineers, nurses, lab technicians, accountants and bookkeepers, rubber manufacturing products makers, weavers, and knitters. SIRs were significantly elevated for high probability of exposure to organic solvents (SIR = 1.4). For benzene exposure, we found significant excesses for overall exposure (SIR = 1.1) and for medium level of exposure (SIR = 1.3). There was no evidence of an association between risk and electromagnetic fields (EMF) exposure. Based on a small number of exposed, SIRs were elevated for both medium probability and high level of exposure to pesticides. The elevations in occupations reported here support some previous reports. Our finding of an increased risk associated with benzene also has been reported previously; the finding for organic solvents is new. However, the literature on the risk of breast cancer related to occupational exposures is limited and there is no consistent body of literature for any of the exposures studied here. Further, many comparisons were made and the problem of multiple hypothesis testing cannot be ignored in a survey such as ours. Am. J. Ind. Med. 34:477–483, 1998. © 1998 Wiley-Liss, Inc.     

Socioeconomic risk factors for bacteraemic pneumococcal pneumonia in adults

SUMMARYDemographic and clinical risk factors are important in guiding vaccination policy for pneumococcal pneumonia. We present data on these variables from a population-based surveillance network covering adult bacteraemic pneumococcal pneumonia (BPP) in the Delaware Valley region from 2002 to 2004. Surveillance data were used with U.S. Census data and a community health survey to calculate stratified incidence rates. Missing data were handled using multiple imputation. Overall rates of adult BPP were 10.6 cases/100 000 person-years. Elevated rates were seen in the elderly (>65 years), Native Americans, African Americans, the less-educated (less than high-school education), the poor, smokers, and individuals with histories of asthma, cancer, or diabetes. Multivariable modelling suggested that income was more robustly associated with risk than African American race. Of methodological interest, this association was not apparent if census block-group median income was used as a proxy for self-reported income. Further research on socioeconomic risk factors for BPP is needed.     

Maternal factors and breast cancer risk among young women

The results from previous studies have provided evidence to support the hypothesised association between intrauterine oestrogen exposure and subsequent risk of breast cancer. Information has not been available to study this relationship for several perinatal factors thought to be related to pregnancy oestrogen levels. Data collected from the mothers of women in two population-based case–control studies of breast cancer in women under the age of 45 years (510 case mothers, 436 control mothers) who were diagnosed between 1983 and 1992 in three western Washington counties were used to investigate further the relationship between intrauterine oestrogen exposure and risk of breast cancer. A pregnancy weight gain of 25–34 pounds was associated with breast cancer risk (odds ratio [OR] = 1.5; 95% confidence interval [CI] 1.1, 2.0); however, women whose mothers gained 35 pounds or more were not at increased risk. Use of antiemetic medication in women with any nausea and vomiting (OR = 2.9; 95% CI 1.1, 8.1) and use of diethylstilboestrol (DES) (OR = 2.3; 95% CI 0.8, 6.4) appeared to be positively associated with breast cancer risk. The results from this study provide limited support for the hypothesis that in utero oestrogen exposure may be related to subsequent breast cancer risk among young women.