Breast cancer risk among women under 55 years of age by joint effects of usage of oral contraceptives and hormone replacement therapy.

OBJECTIVE: To assess effects on breast cancer risk of exposure to both oral contraceptives and menopausal hormones, an increasingly common exposure. DESIGN: A case-control study of breast cancer among women under the age of 55 years in Atlanta, GA involving 1,031 cases and 919 population controls was conducted. RESULTS: Ever use of oral contraceptives was associated with a relative risk of 1.1 (95% 0.9-1.4), whereas the relative risk for hormone replacement therapy was 0.9 (95% CI 0.7-1.2). Seventeen percent of the cases versus 19% of the population controls reported exposure to both agents, resulting in a relative risk of 1.0 (95% CI 0.7-1.4) relative to those unexposed to either preparation. Although there was little variation in risk associated with joint effects by either age or race, there were statistically nonsignificant elevations in risk for this exposure among women who had experienced a natural menopause (relative risk = 2.0, 95% CI 0.7-5.6), were relatively thin (relative risk = 1.5, 0.8-3.0), or who had a first degree relative with breast cancer (relative risk = 2.0, 0.6-7.0). When joint effects of longer term use of both agents were considered, subjects who reported use of oral contraceptives for 10 or more years and hormone replacement for 3 or more years had a relative risk of 3.2 (95% CI 1.4-7.4) compared with nonusers of either preparation. CONCLUSIONS: Although our results must be cautiously interpreted given small numbers within subgroups, they raise concern and emphasize the need for further evaluation on breast cancer risk of the increasingly common exposure to both oral contraceptives and hormone replacement therapy.

Estimating model-adjusted risks, risk differences, and risk ratios from complex survey data.

There is increasing interest in estimating and drawing inferences about risk or prevalence ratios and differences instead of odds ratios in the regression setting. Recent publications have shown how the GENMOD procedure in SAS (SAS Institute Inc., Cary, North Carolina) can be used to estimate these parameters in non-population-based studies. In this paper, the authors show how model-adjusted risks, risk differences, and risk ratio estimates can be obtained directly from logistic regression models in the complex sample survey setting to yield population-based inferences. Complex sample survey designs typically involve some combination of weighting, stratification, multistage sampling, clustering, and perhaps finite population adjustments. Point estimates of model-adjusted risks, risk differences, and risk ratios are obtained from average marginal predictions in the fitted logistic regression model. The model can contain both continuous and categorical covariates, as well as interaction terms. The authors use the SUDAAN software package (Research Triangle Institute, Research Triangle Park, North Carolina) to obtain point estimates, standard errors (via linearization or a replication method), confidence intervals, and P values for the parameters and contrasts of interest. Data from the 2006 National Health Interview Survey are used to illustrate these concepts.

Race, gender, and incident dialysis patients' reported health status and quality of life.

Patient-reported physical and mental health status, along with disease-specific concerns ("quality of life") reported by patients, provide information about experience on dialysis that can help to improve patient care. Among prevalent hemodialysis (HD) patients, blacks have been shown to report higher health status and quality of life scores than whites, but whether similar race differences characterize incident patients who start regular dialysis is not known. Health status and quality of life, measured by the Kidney Disease Quality of Life-Short Form, reported by black men, black women, white men, and white women who initiated HD and peritoneal dialysis (PD) in the Dialysis Morbidity and Mortality Study (DMMS) Wave 2 were examined. After adjustment for patients' sociodemographic and clinical characteristics, the only race differences observed were that among HD patients, black women scored highest on the burden of kidney disease measure (lower perceived burden), and among PD patients, black men had the lowest satisfaction with care scores. It is possible that differences between blacks' and whites' reported health status and quality of life become more evident as patients' dialysis vintage increases, a hypothesis that requires following a well-characterized incident cohort over time. These findings add to existing evidence that minority patients on dialysis report less satisfaction with their care than do white patients, an important area for continued study.

Occupation and breast cancer in women 20-44 years of age (United States).

OBJECTIVE: To examine the relation between breast cancer risk and job history among women 20-44 years of age who participated in a multi-center, population-based, case-control study. METHODS: Participants consisted of women newly diagnosed with breast cancer (1642) and controls identified by random-digit dialing (1494). Details about the three longest jobs were collected and coded by an industrial hygienist. Odds ratios and 95% confidence intervals were calculated and adjusted for age, study site, and other breast cancer risk factors. RESULTS: Several occupational and industrial categories were found to influence breast cancer risk. Stratification of the study population by parity revealed differences in breast cancer risk between the two groups for several occupational categories, including teachers, librarians or counselors (increased risk only among parous women) and natural scientists and mathematicians (decreased risk only among nulliparous women). CONCLUSIONS: This is among the first population-based case-control studies to examine occupational history and breast cancer risk in young women, with the ability to consider a wide array of potential confounders, including reproductive characteristics. This study provides further evidence of an increased breast cancer risk for several occupations and industries. Other findings were not as strongly supported by previous investigations.

Breast cancers among very young premenopausal women (United States).

OBJECTIVE: To assess risk factors for breast cancer among very young compared to older premenopausal women. METHODS: Between 1990 and 1992 a population-based case-control study conducted in Atlanta, GA, Seattle/Puget Sound, WA, and central NJ interviewed 3307 premenopausal women aged 20-54 years. Logistic regression models estimated adjusted relative risks (RR) and 95% confidence intervals (CI) for each of three 10-year age groups. RESULTS: Among the youngest age group (<35 years, n = 545), significant predictors of risk included African-American race (RR = 2.66: 95% CI 1.4-4.9) and recent use of oral contraceptives (RR = 2.26; 95% CI 1.4-3.6). Although these relationships were strongest for estrogen receptor-negative (ER-) tumors (RRs of 3.30 for race and 3.56 for recent oral contraceptive use), these associations were also apparent for young women with ER+ tumors. Delayed childbearing was a risk factor for ER+ tumors among the older premenopausal women (Ptrend < 0.01), but not for women <35 years in whom early childbearing was associated with an increased risk, reflecting a short-term increase in risk immediately following a birth. Family history of early-onset breast cancer was more strongly associated with risk among women <35 years (RR = 3.22) than those 45-54 years (RR = 1.51). Risk factors for premenopausal breast cancer not significantly modified by age at diagnosis included early age at menarche, low body mass index, and heavy alcohol consumption. CONCLUSION: These findings suggest the possibility that women who develop breast cancers at very young ages may be etiologically as well as clinically distinct.

Health and professional characteristics of lesbian and heterosexual women physicians.

OBJECTIVE: To determine whether lesbian and heterosexual female physicians differ on health, professional, and demographic characteristics. METHODS: The Women Physicians' Health Study (WPHS), a mailed questionnaire sample survey, was completed by 4501 women physicians (59% response rate), of whom 115 were identified as lesbians and 4177 were identified as heterosexuals. Lesbian and heterosexual were defined by response to items about self-identification and sexual behavior. Dependent variables are self-reported health status and behavior and professional characteristics. RESULTS: Lesbians weighed more and were more likely to report histories of depression or sexual abuse, family histories of alcoholism, and orientation-related workplace harassment (all p = .01). On the other hand, they were more likely to comply with mammogram screening (p < .01). CONCLUSIONS: Many health status and behavior differences found in other studies of lesbian and heterosexual women were less pronounced here. This may be because the population of female physicians is more homogeneous, but perhaps also because the size of our lesbian sample was limited (n = 115). However, even with the buffer of high socioeconomic status and medical education, lesbian physicians seem to have a somewhat higher cumulative risk of disease compared to their heterosexual female colleagues.

The effects of continuing medical education credits on physician response rates to a mailed questionnaire.

This study investigated whether the opportunity to obtain Continuing Medical Education (CME) credit together with a five-dollar bill increased response rates and questionnaire completion rates in a physician survey involving mailed questionnaires. One thousand, three hundred and fourteen cardiologists, family practitioners, general internists (non-surgeons) and 264 vascular surgeons randomly identified from the American Medical Association database participated. After two, of up to four, questionnaire mailings, the opportunity to obtain CME credit and a five-dollar bill were included with questionnaire mailings. Among non-surgeons, 26.5% responded to pre-incentive mailings and 30.2% of those initially unresponsive replied after the interventions. Among surgeons, 39% responded to pre-incentive mailings and 32.7% of those initially unresponsive replied after the interventions. In conclusion, the opportunity to receive CME credit combined with a small monetary incentive is an effective motivation for physicians participating in a study involving mailed questionnaires.

Atherosclerotic risk factor reduction in peripheral arterial diseasea: results of a national physician survey.

OBJECTIVE: Individuals with peripheral arterial disease (PAD) have a 3- to 6-fold increased risk of coronary heart disease and stroke compared to those without PAD. We documented physician-reported practice behavior, knowledge, and attitudes regarding atherosclerotic risk factor reduction in patients with PAD. DESIGN: National physician survey. PATIENTS/PARTICIPANTS: General internists (N = 406), family practitioners (N = 435), cardiologists (N = 473), and vascular surgeons (N = 264) randomly identified using the American Medical Association's physician database. MEASUREMENTS AND MAIN RESULTS: Physicians were randomized to 1 of 3 questionnaires describing a) a 55- to 65-year-old patient with PAD; b) a 55- to 65-year-old patient with coronary artery disease (CAD), or c) a 55- to 65-year-old patient without clinically evident atherosclerosis (no disease). A mailed questionnaire was used to compare physician behavior, knowledge, and attitude regarding risk factor reduction for each patient. Rates of prescribed antiplatelet therapy were significantly lower for the patient with PAD than for the patient with CAD. Average low-density lipoprotein levels at which physicians "almost always" initiated lipid-lowering drugs were 121.6 +/- 23.5 mg/dL, 136.3 +/- 28.9 mg/dL, and 149.7 +/- 24.4 mg/dL for the CAD, PAD, and no-disease patients, respectively (P <.001). Physicians stated that antiplatelet therapy (P <.001) and cholesterol-lowering therapy (P <.001) were extremely important significantly more often for the CAD than for the PAD patient. Perceived importance of risk factor interventions was highly correlated with practice behavior. Compared to other specialties, cardiologists had lowest thresholds, whereas vascular surgeons had the highest thresholds for initiating cholesterol-lowering interventions for the patient with PAD. Cardiologists were significantly more likely to report "almost always" prescribing antiplatelet therapy for the patient with PAD than were all other physicians. CONCLUSIONS: Deficiencies in physician knowledge and attitudes contribute to lower rates of atherosclerotic risk factor reduction for patients with PAD. Reversing these deficiencies may reduce the high rates of cardiovascular morbidity and mortality associated with PAD.

Risk of breast cancer classified by joint estrogen receptor and progesterone receptor status among women 20-44 years of age.

To gain insight into whether breast cancer tumors jointly classified by estrogen receptor (ER) and progesterone receptor (PR) status represent diseases with differing etiologies, data from a population-based case-control study of US women 20-44 years of age were analyzed. Cases included 1,556 women diagnosed between 1990 and 1992. Age- and geographic-frequency-matched controls included 1,397 women identified by random digit dialing. Heterogeneity between ER+PR+ and ER-PR- tumors was most pronounced in relation to age, race, and recreational exercise at 12-13 years of age. Multivariate-adjusted odds ratios for ER+PR+ tumors were 0.64 (95% confidence interval (CI): 0.47, 0.89) for 30-34 versus 40-44 years of age, 0.89 (95% CI: 0.63, 1.25) for Black versus White race, and 0.84 (95% CI: 0.68, 1.03) for exercise at 12-13 years of age above versus at or below the median. Corresponding odds ratios for ER-PR- tumors were 1.24 (95% CI: 0.86, 1.77), 1.51 (95% CI: 1.07, 2.14), and 1.15 (95% CI: 0.90, 1.48). Risk of ER-PR- cancer in relation to menstrual and reproductive (parity and lactation) characteristics, alcohol consumption, and family history of breast cancer was similar to that observed for ER+PR+ tumors. These findings only modestly support the hypothesis that hormonally related risk factors have differing relations with ER+PR+ versus ER-PR- tumors among younger women.

Exploration of threshold analysis in the relation between stressful life events and preterm delivery.

Biologic evidence suggests that the hormones activated by stress affect gestational length, but the results of epidemiologic investigations are inconsistent. The authors of this paper know of no threshold models that have been studied; these models assume that stress does not affect preterm delivery until a certain amount of stress has been experienced but that each unit of stress above the threshold adds to the risk of preterm delivery. By using standard logistic regression, the authors compared threshold and nonthreshold models of the relation between number of stressful life events and preterm delivery in 11 US states. They used data on 1990-1995 births from the Pregnancy Risk Assessment Monitoring System. The risk of preterm delivery among multiparas who gave birth in 1990-1993 increased 7% for each event over five they experienced, but no relation was found for 1994-1995 births. Among primiparas who gave birth in 1994-1995, the risk increased 5% for each event over two, but no relation was found for 1990-1993 births. These results suggest that a threshold model may fit the relation between stress and preterm delivery better than one with no threshold. However, the inconsistent results are difficult to reconcile with a biologic threshold in the relation between stress and preterm delivery.

Increased risk of early-stage breast cancer related to consumption of sweet foods among women less than age 45 in the United States.

OBJECTIVES: To evaluate the associations of dietary macronutrients, food groups, and eating patterns with risk of breast cancer in a population-based case-control study. METHODS: In this study among women 20-44 years of age, 568 cases with breast cancer and 1451 population-based controls were included. They completed a detailed in-person interview, a self-administered food-frequency questionnaire and were measured for anthropometric indices. Logistic regression was used to estimate odds ratios (OR) and their 95% confidence intervals (CI) of breast cancer, adjusted for age, study site, race, education, alcohol consumption, oral contraceptive usage, smoking status, and body mass index. RESULTS: There was no association between breast cancer risk and intake of calories, macronutrients, or types of fat. Risk of breast cancer was unrelated to intakes of a variety of food groups, including red meats, dairy, high-fat snacks and desserts, or foods high in animal fat. Increased risk was observed for high intake of a food group composed of sweet items, particularly sodas and desserts. Risk increased linearly with percent of calories from sweets and frequency of sweets intake. Consumption of sweets 9.8 or more times per week compared with <2.8 times per week was associated with an adjusted OR of 1.32 (95% CI = 1.0-1.8). This association did not appear to be due to the high-fat foods or carbonated beverages that comprised the food group. Compared with women reporting one or two meals and snacks per day, reduced risks were noted for women reporting six or more (OR = 0.69, 95% CI = 0.4-1.1). CONCLUSIONS: These data suggest a modest relationship between intakes of sweet items with risk of in-situ and localized breast cancer in young women. This relation is consistent with the hypothesized link of high insulin exposure and risk of breast cancer. There was some suggestion that women who ate many times during the day were at reduced risk of disease, which is also consistent with an insulin-related mechanism.

La mortalidad por tétanos neonatal en Veracruz, México, en 1989 / Neonatal tetanus mortality in Veracruz, México, 1989

Este artículo describe una encuesta realizada en el estado de Veracruz, México, para estimar la mortalidad por tétanos neonatal. La encuesta, que entraño visitas a 72 720 familias, generó datos sobre 8401 nacidos vivos y 209 defunciones neonatales de abril de 1988 a mayo de 1989. De las 209 defunciones, 26 se ajustaban a la definición de la OMS de casos de defunción por tétanos neonatal. La mortalidad estimada por esta enfermedad fue de 3,1 defunciones por 1000 niños nacidos vivos (IC95 por ciento=1,7 a 4,5). La comparación de esta tasa con las cifras notificadas sugiere que por cada defunción por tétanos neonatal registrada en Veracruz durante el período de estudio, otros 50 o más no se notificaron. Además de la encuesta se efectuó un estudio de casos y testigos para evaluar los factores de riesgo de tétanos neonatal que pueden prevenirse. Datos limitados sobre 13 casos de defunción por tétanos neonatal y 217 testigos mostraron un riesgo aumentado en niños que nacieron en el hogar y cuyos padres descendían de indios mexicanos. A cinco de los trece niños fallecidos se les había cortado el cordón umbilical con un instrumento de uso doméstico o un instrumento tradicional con filo, como una caña vegetal, en comparación con ninguno de los 217 testigos. La eficacia observada de la vacunación con dos o más dosis de toxoide tetánico fue de 70 por ciento (IC95 por ciento=52 a 100). Tanto las madres de los neonatos que murieron de tétanos como la de los testigos habían desaprovechado un promedio de cinco oportunidades de recibir toxoide tetánico. Estos resultados subrayan la necesidad de establecer un programa de salud perinatal orientado a las poblaciones mexicanas de alto riesgo

Neonatal tetanus mortality in Veracruz, Mexico, 1989

This article describes a survey conducted in the State of Veracruz, Mexico, to estimate neonatal tetanus (NNT) mortality. The survey, which entailed visits to 72 720 households, collected data on 8 401 live births and 209 infants deaths ocurring between April 1988 and May 1989. Twenty-six of the 209 fatalities conformed to a WHO standard case definition of death from neonatal tetanus. The estimated neonatal tetanus mortality was thus 3.1 deaths per 1 000 live births (95 percent confidence limits = 1.7,4.5). Comparison of this rate to reported figures suggests that for every NNT death recorded in Veracruz during the study period, as many as 50 others went unreported. A case-control study nested within the survey was conducted to assess preventable NNT risk factors. Limited information on 13 NNT deaths and 217 controls showed an increased risk for neonates who were delivered at home and whose parents' ethnic background was Mexican Indian. Five of the 13 fatalities had their umbilical cords cut with a domestic or traditional cutting tool such as a reed cane, as compared to none of the 217 controls. The observed vaccine efficacy of 2 = doses of tetanus toxoid was 70 percent (95 percent confidence limits = 52,100). Both the mothers of neonates who died of NNT and their controls missed an average of five opportunities to receive tetanus toxoid. These findings underscore the need to launch a perinatal health program serving Mexico's high-risk poulations (AU)

Neonatal tetanus mortality in Veracruz, Mexico, 1989

This article describes a survey conducted in the State of Veracruz, Mexico, to estimate neonatal tetanus (NNT) mortality. The survey, which entailed visits to 72 720 households, collected data on 8 401 live births and 209 infants deaths ocurring between April 1988 and May 1989. Twenty-six of the 209 fatalities conformed to a WHO standard case definition of death from neonatal tetanus. The estimated neonatal tetanus mortality was thus 3.1 deaths per 1 000 live births (95 percent confidence limits = 1.7,4.5). Comparison of this rate to reported figures suggests that for every NNT death recorded in Veracruz during the study period, as many as 50 others went unreported. A case-control study nested within the survey was conducted to assess preventable NNT risk factors. Limited information on 13 NNT deaths and 217 controls showed an increased risk for neonates who were delivered at home and whose parents' ethnic background was Mexican Indian. Five of the 13 fatalities had their umbilical cords cut with a domestic or traditional cutting tool such as a reed cane, as compared to none of the 217 controls. The observed vaccine efficacy of 2 = doses of tetanus toxoid was 70 percent (95 percent confidence limits = 52,100). Both the mothers of neonates who died of NNT and their controls missed an average of five opportunities to receive tetanus toxoid. These findings underscore the need to launch a perinatal health program serving Mexico's high-risk poulations (AU)

This article will also be published in Spanish in the BOSP. Vol. 119, 1995

La mortalidad por tétanos neonatal en Veracruz, México, en 1989 / Neonatal tetanus mortality in Veracruz, México, 1989

Este artículo describe una encuesta realizada en el estado de Veracruz, México, para estimar la mortalidad por tétanos neonatal. La encuesta, que entraño visitas a 72 720 familias, generó datos sobre 8401 nacidos vivos y 209 defunciones neonatales de abril de 1988 a mayo de 1989. De las 209 defunciones, 26 se ajustaban a la definición de la OMS de casos de defunción por tétanos neonatal. La mortalidad estimada por esta enfermedad fue de 3,1 defunciones por 1000 niños nacidos vivos (IC95 por ciento=1,7 a 4,5). La comparación de esta tasa con las cifras notificadas sugiere que por cada defunción por tétanos neonatal registrada en Veracruz durante el período de estudio, otros 50 o más no se notificaron. Además de la encuesta se efectuó un estudio de casos y testigos para evaluar los factores de riesgo de tétanos neonatal que pueden prevenirse. Datos limitados sobre 13 casos de defunción por tétanos neonatal y 217 testigos mostraron un riesgo aumentado en niños que nacieron en el hogar y cuyos padres descendían de indios mexicanos. A cinco de los trece niños fallecidos se les había cortado el cordón umbilical con un instrumento de uso doméstico o un instrumento tradicional con filo, como una caña vegetal, en comparación con ninguno de los 217 testigos. La eficacia observada de la vacunación con dos o más dosis de toxoide tetánico fue de 70 por ciento (IC95 por ciento=52 a 100). Tanto las madres de los neonatos que murieron de tétanos como la de los testigos habían desaprovechado un promedio de cinco oportunidades de recibir toxoide tetánico. Estos resultados subrayan la necesidad de establecer un programa de salud perinatal orientado a las poblaciones mexicanas de alto riesgo

Se publica en inglés en el Bull. PAHO. Vol. 29(2), 1995