A population-based case-control study of urinary bisphenol A concentrations and risk of endometriosis.

STUDY QUESTION: Is bisphenol A (BPA) exposure associated with the risk of endometriosis, an estrogen-driven disease of women of reproductive age? SUMMARY ANSWER: Our study suggests that increased urinary BPA is associated with an increased risk of non-ovarian pelvic endometriosis, but not ovarian endometriosis. WHAT IS KNOWN ALREADY: BPA, a high-volume chemical used in the polymer industry, has been the focus of public and scientific concern given its demonstrated estrogenic effects in vivo and in vitro and widespread human exposure. Prior studies of BPA and endometriosis have yielded inconsistent results and were limited by the participant sampling framework, small sample size or use of serum (which has very low/transient concentrations) instead of urine to measure BPA concentrations. STUDY DESIGN, SIZE, DURATION: We used data from the Women's Risk of Endometriosis study, a population-based case-control study of endometriosis, conducted among female enrollees of a large healthcare system in the US Pacific Northwest. Cases were women with incident, surgically confirmed endometriosis diagnosed between 1996 and 2001 and controls were women randomly selected from the defined population that gave rise to the cases, without a current or prior diagnosis of endometriosis. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: Total urinary BPA concentrations were measured in 143 cases and 287 population-based controls using single, spot urine samples collected after disease diagnosis in cases. Total urinary BPA concentration (free and conjugated species) was quantified using a high-performance liquid chromatography-mass spectrometry method. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression, adjusting for urinary creatinine concentrations, age and reference year. We also evaluated the association by disease subtypes, ovarian and non-ovarian pelvic endometriosis, that may be etiologically distinct. MAIN RESULTS AND THE ROLE OF CHANCE: We did not observe a statistically significant association between total urinary BPA concentrations and endometriosis overall. We did observe statistically significant positive associations when evaluating total urinary BPA concentrations in relation to non-ovarian pelvic endometriosis (second versus lowest quartile: OR 3.0; 95% CI: 1.2, 7.3; third versus lowest quartile: OR 3.0; 95% CI: 1.1, 7.6), but not in relation to ovarian endometriosis. LIMITATIONS, REASONS FOR CAUTION: Given the short elimination half-life of BPA, our study was limited by the timing of collection of the single urine sample, that occurred after case diagnosis. Thus, our BPA measurements may not accurately represent the participants' levels during the etiologically relevant time period for endometriosis development. In addition, since it was not feasible in this population-based study to surgically confirm the absence of disease, it is possible that some controls may have had undiagnosed endometriosis. WIDER IMPLICATIONS OF THE FINDINGS: By using population-based data, it is more likely that the controls represented the underlying frequency of BPA exposure in contrast to prior studies that used for comparison control women undergoing surgical evaluation, where the indication for surgery may be associated with BPA exposure. The significant associations observed in this study suggest that BPA may affect the normal dynamic structural changes of hormonally responsive endometrial tissue during the menstrual cycle, promoting the establishment and persistence of refluxed endometrial tissue in cases with non-ovarian pelvic endometriosis. Further research is warranted to confirm our novel findings in endometriosis subtypes that may be etiologically distinct. STUDY FUNDING/COMPETING INTERESTS: This work was supported by the National Institutes of Health, National Institute of Environmental Health Sciences (grant number R03 ES019976), the Eunice Kennedy Shriver National Institute of Child Health and Human Development (grant number R01 HD033792); US Environmental Protection Agency, Science to Achieve Results (STAR) (grant number R82943-01-0) and National Institute of Nursing Research (grant number F31NR013092) to KU for training support. This work was supported in part by the Intramural Research Program of the National Institutes of Health, National Institute of Environmental Health Sciences. The content is solely the responsibility of the authors and does not necessarily represent the official view of the National Institute of Child Health and Human Development, National Institute of Environmental Health Sciences, National Institute of Nursing Research or the National Institutes of Health. The authors have no actual or potential competing financial interests. TRIAL REGISTRATION NUMBER: Not applicable.

Phthalates and risk of endometriosis.

BACKGROUND: Phthalates are ubiquitous environmental chemicals with endocrine disruptive properties. The impact of these chemicals on endocrine-related disease in reproductive-age women is not well understood. OBJECTIVE: To investigate the relationship between urinary phthalate metabolite concentrations and the risk of a hormonally-driven disease, endometriosis, in reproductive-age women. METHODS: We used data from a population-based case-control study of endometriosis, conducted among female enrollees of a large healthcare system in the U.S. Pacific Northwest. We measured urinary phthalate metabolite concentrations on incident, surgically-confirmed cases (n=92) diagnosed between 1996 and 2001 and population-based controls (n=195). Odds ratios (OR), and 95% confidence intervals (CI) were estimated using unconditional logistic regression, adjusting for urinary creatinine concentrations, age, and reference year. RESULTS: The majority of women in our study had detectable concentrations of phthalate metabolites. We observed a strong inverse association between urinary mono-(2-ethyl-5-hexyl) phthalate (MEHP) concentration and endometriosis risk, particularly when comparing the fourth and first MEHP quartiles (aOR 0.3, 95% CI: 0.1-0.7). Our data suggested an inverse association between endometriosis and urinary concentrations of other di-2-ethylhexyl phthalate (DEHP) metabolites (mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP)) and ∑DEHP, however, the confidence intervals include the null. Our data also suggested increased endometriosis risk with greater urinary concentrations of mono-benzyl phthalate (MBzP) and mono-ethyl phthalate (MEP), although the associations were not statistically significant. CONCLUSIONS: Exposure to select phthalates is ubiquitous among female enrollees of a large healthcare system in the U.S. Pacific Northwest. The findings from our study suggest that phthalates may alter the risk of a hormonally-mediated disease among reproductive-age women.

Breastfeeding history and adenomyosis risk using a novel case-control study design.

OBJECTIVE: To evaluate the association between breastfeeding history, including lifetime exclusive breastfeeding, and risk of adenomyosis. DESIGN: We used data from a case-control study designed with 2 control groups to address the challenge of selecting noncases for a valid epidemiologic study when cases are identified by hysterectomy. The case-control study was conducted among premenopausal and postmenopausal enrollees aged 18-59 years in a large, integrated health care system in western Washington state. PATIENT(S): Cases were enrollees with incident, pathology-confirmed adenomyosis diagnosed during 2001-2006 (n = 386). The 2 control groups were as follows: (1) randomly selected age-matched enrollees with intact uteri ("population controls," n = 323) and (2) hysterectomy controls (n = 233). INTERVENTION(S): Data on breastfeeding history were collected by in-person interviews. For each reported live birth, participants were asked whether they breastfed, along with infant age at supplemental feeding introduction and breastfeeding discontinuation. MAIN OUTCOME MEASURE(S): Among participants with at least 1 live birth (330 cases, 246 population controls, and 198 hysterectomy controls), we used unconditional logistic regression to estimate adjusted odds ratios and 95% confidence intervals (CIs) for the associations between the following: (1) ever breastfeeding, (2) ever breastfeeding for ≥8 weeks, (3) lifetime breastfeeding, and (4) lifetime exclusive breastfeeding and risk of adenomyosis. Analyses were adjusted for age, reference year, smoking, education, and parity. RESULT(S): In analyses comparing cases with population controls, we observed a 40% decreased odds of adenomyosis with a history of ever breastfeeding (adjusted odds ratio, 0.6; 95% CI, 0.3-1.0) and breastfeeding for ≥8 weeks (adjusted odds ratio, 0.6; 95% CI, 0.4-0.8). The strongest associations, 60%-70% decreased odds of adenomyosis, were observed with ≥12 months of lifetime breastfeeding (vs. <3 months) (adjusted odds ratio, 0.4; 95% CI, 0.2-0.6) and 9 to <12 months of lifetime exclusive breastfeeding (vs. <3 months) (adjusted odds ratio, 0.3; 95% CI, 0.2-0.6), comparing cases to population controls. In analyses using hysterectomy controls, we observed similar patterns of associations slightly attenuated in magnitude. CONCLUSION(S): Breastfeeding history was associated with a 40% decreased odds of adenomyosis, a condition that can confer substantial morbidity and requires hysterectomy for definitive treatment. The consistency of our findings with that of a previous study lends support that breastfeeding may modify risk of adenomyosis.

Maternal and neonatal outcomes associated with treating hypertension in pregnancy at different thresholds.

INTRODUCTION: In the United States, there has been controversy over whether treatment of mild-to-moderate hypertension during pregnancy conveys more benefit than risk. OBJECTIVE: The objective of the study was to compare risks and benefits of treatment of mild-to-moderate hypertension during pregnancy. METHODS: This retrospective cohort study included 11,871 pregnant women with mild-to-moderate hypertension as defined by blood pressure (BP) values from three Kaiser Permanente regions between 2005 and 2014. Data were extracted from electronic health records. Dynamic marginal structural models with inverse probability weighting and informative censoring were used to compare risks of adverse outcomes when beginning antihypertensive medication treatment at four BP thresholds (≥155/105, ≥150/100, ≥145/95, ≥140/90 mm Hg) compared with the recommended threshold in the United States at that time, ≥160/110 mm Hg. Outcomes included preeclampsia, preterm birth, small-for-gestational-age (SGA), Neonatal Intensive Care Unit (NICU) care, and stillbirth. Primary analyses allowed 2 weeks for medication initiation after an elevated BP. Several sensitivity and subgroup (i.e., race/ethnicity and pre-pregnancy body mass index) analyses were also conducted. RESULTS: In primary analyses, medication initiation at lower BP thresholds was associated with greater risk of most outcomes. Comparing the lowest (≥140/90 mm Hg) to the highest BP threshold (≥160/110 mm Hg), we found an excess risk of preeclampsia (adjusted Risk Difference (aRD) 38.6 per 100 births, 95% Confidence Interval (CI): 30.6, 46.6), SGA (aRD: 10.2 per 100 births, 95% CI: 2.6, 17.8), NICU admission (aRD: 20.2 per 100 births, 95% CI: 12.6, 27.9), and stillbirth (1.18 per 100 births, 95% CI: 0.27, 2.09). The findings did not reach statistical significance for preterm birth (aRD: 2.5 per 100 births, 95% CI: -0.4, 5.3). These relationships were attenuated and did not always reach statistically significance when comparing higher BP treatment thresholds to the highest threshold (i.e., ≥160/110 mm Hg). Sensitivity and subgroup analyses produced similar results. CONCLUSIONS: Initiation of antihypertensive medication at mild-to-moderate BP thresholds (140-155/90-105 mm Hg; with the largest risk consistently associated with treatment at 140/90 mm Hg) may be associated with adverse maternal and neonatal outcomes. Limitations include inability to measure medication adherence.

Maternal and neonatal outcomes of antihypertensive treatment in pregnancy: A retrospective cohort study.

OBJECTIVE: To compare maternal and infant outcomes with different antihypertensive medications in pregnancy. DESIGN: Retrospective cohort study. SETTING: Kaiser Permanente, a large healthcare system in the United States. POPULATION: Women aged 15-49 years with a singleton birth from 2005-2014 treated for hypertension. METHODS: We identified medication exposure from automated pharmacy data based on the earliest dispensing after the first prenatal visit. Using logistic regression, we calculated weighted outcome prevalences, adjusted odds ratios (aORs) and 95% confidence intervals, with inverse probability of treatment weighting to address confounding. MAIN OUTCOME MEASURES: Small for gestational age, preterm delivery, neonatal and maternal intensive care unit (ICU) admission, preeclampsia, and stillbirth or termination at > 20 weeks. RESULTS: Among 6346 deliveries, 87% with chronic hypertension, the risk of the infant being small for gestational age (birthweight < 10th percentile) was lower with methyldopa than labetalol (prevalence 13.6% vs. 16.6%; aOR 0.77, 95% CI 0.63 to 0.92). For birthweight < 3rd percentile the aOR was 0.57 (0.39 to 0.80). Compared with labetalol (26.0%), risk of preterm delivery was similar for methyldopa (26.5%; aOR 1.10 [0.95 to 1.27]) and slightly higher for nifedipine (28.5%; aOR 1.25 [1.06 to 1.46]) and other ß-blockers (31.2%; aOR 1.58 [1.07 to 2.23]). Neonatal ICU admission was more common with nifedipine than labetalol (25.9% vs. 23.3%, aOR 1.21 [1.02 to 1.43]) but not elevated with methyldopa. Risks of other outcomes did not differ by medication. CONCLUSIONS: Risk of most outcomes was similar comparing labetalol, methyldopa and nifedipine. Risk of the infant being small for gestational age was substantially lower for methyldopa, suggesting this medication may warrant further consideration.

Identifying hypertensive disorders of pregnancy, a comparison of two epidemiologic definitions.

Introduction: Studies of hypertension in pregnancy that use electronic health care data generally identify hypertension using hospital diagnosis codes alone. We sought to compare results from this approach to an approach that included diagnosis codes, antihypertensive medications and blood pressure (BP) values. Materials and methods: We conducted a retrospective cohort study of 1,45,739 pregnancies from 2009 to 2014 within an integrated healthcare system. Hypertensive pregnancies were identified using the "BP-Inclusive Definition" if at least one of three criteria were met: (1) two elevated outpatient BPs, (2) antihypertensive medication fill plus an outpatient hypertension diagnosis, or (3) hospital discharge diagnosis for preeclampsia or eclampsia. The "Traditional Definition" considered only delivery hospitalization discharge diagnoses. Outcome event analyses compared rates of preterm delivery and small for gestational age (SGA) between the two definitions. Results: The BP-Inclusive Definition identified 14,225 (9.8%) hypertensive pregnancies while the Traditional Definition identified 13,637 (9.4%); 10,809 women met both definitions. Preterm delivery occurred in 20.9% of BP-Inclusive Definition pregnancies, 21.8% of Traditional Definition pregnancies and 6.6% of non-hypertensive pregnancies; for SGA the numbers were 15.6, 16.3, and 8.6%, respectively (p < 0.001 for all events compared to non-hypertensive pregnancies). Analyses in women meeting only one hypertension definition (21-24% of positive cases) found much lower rates of both preterm delivery and SGA. Conclusion: Prevalence of hypertension in pregnancy was similar between the two study definitions. However, a substantial number of women met only one of the study definitions. Women who met only one of the hypertension definitions had much lower rates of adverse neonatal events than women meeting both definitions.

Diet and risk of endometriosis in a population-based case-control study.

Diet plausibly has a role in the aetiology of endometriosis through effects on steroid hormone levels; however, few published studies have examined the diet and endometriosis risk. We evaluated dietary risk factors for endometriosis in a population-based case-control study. Cases were 284 Group Health (GH) enrollees aged 18-49 years with newly diagnosed, surgically confirmed endometriosis between 1996 and 2001. Controls were 660 randomly selected age-matched female GH enrollees without a history of endometriosis. Nutrients and selected food groups were assessed using the Women's Health Initiative FFQ. OR of endometriosis risk associated with dietary exposures were estimated using unconditional logistic regression and adjusted for identified covariates. Increased total fat consumption was associated with decreased endometriosis risk (fourth quartile v. lowest: OR 0·5, 95% CI 0·2, 1·0, P-trend = 0·12). Increased ß-carotene consumption and servings/d of fruit were associated with increased risk (ß-carotene third quartile v. lowest: OR 1·7, 95% CI 1·1, 2·6; fourth quartile v. lowest: OR 1·6, 95% CI 1·0, 2·5, P-trend 0·16; fruit >2 servings/d v. < 1: OR 1·5, 95% CI 1·0, 2·3, P-trend = 0·04). We also found a suggestion of decreased endometriosis risk associated with the consumption of dairy products (2 servings/d v. ≤ 1: OR 0·6, >2 servings/d v. ≤ 1: OR 0·7), but this association was not statistically significant for the highest tertile. The present study suggests that specific dietary components may be associated with endometriosis risk.

Gestational weight gain and adverse pregnancy outcomes by pre-pregnancy BMI category in women with chronic hypertension: A cohort study.

OBJECTIVES: It is important to understand relationships of gestational weight gain with adverse pregnancy outcomes in women with chronic hypertension, given their high baseline risk of adverse outcomes. We assessed associations of gestational weight gain with adverse pregnancy outcomes in women with chronic hypertension by pre-pregnancy body mass index categories. STUDY DESIGN: We identified 14,369 women with chronic hypertension using electronic health records from 3 integrated health care delivery systems (2005-2014). Gestational weight gain-for-gestational age charts were used to calculate gestational weight gain z-scores, which account for gestational age. Modified Poisson regression models using generalized estimating equations were used to calculate relative risks and 95% confidence intervals, adjusted for sociodemographic and medical characteristics. MAIN OUTCOME MEASUREMENTS: Preeclampsia, preterm delivery, cesarean delivery, neonatal intensive care unit admission, birthweight (extracted from the electronic health record). RESULTS: In women with normal weight or overweight, low gestational weight gain (z-score < -1) was associated with 27-28% greater risk of preterm delivery and 48-82% greater risk of small-for-gestational age birthweight, while high gestational weight gain (z-score > 1) was associated with 40-90% greater risk of preeclampsia and 59-113% greater risk of large-for-gestational age birthweight. In women with obesity, low gestational weight gain was associated with 27-54% lower risk of several adverse pregnancy outcomes, including preeclampsia and cesarean delivery. CONCLUSIONS: In women with chronic hypertension and normal weight or overweight, moderate gestational weight gain may confer the lowest risk of adverse outcomes. In women with chronic hypertension and obesity, low gestational weight gain may be necessary for the lowest risk of adverse pregnancy outcomes.

Physical activity, physical exertion, and miscarriage risk in women textile workers in Shanghai, China.

BACKGROUND: Strenuous occupational physical activity and physical demands may be risk factors for adverse reproductive outcomes. METHODS: A retrospective study in the Shanghai, China textile industry study collected women's self-reported reproductive history. Occupational physical activity assessment linked complete work history data to an industry-specific job-exposure matrix. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by multivariate logistic regression for the first pregnancy outcome and utilized generalized estimating equations to consider all pregnancies per woman. RESULTS: Compared with women employed in sedentary jobs, a reduced risk of miscarriage was found for women working in jobs with either light (OR 0.18, 95% CI: 0.07, 0.50) or medium (OR 0.24, 95% CI: 0.08, 0.66) physical activity during the first pregnancy and over all pregnancies (light OR 0.32, 95% CI: 0.17, 0.61; medium OR 0.43, 95% CI: 0.23, 0.80). Frequent crouching was associated with elevated risk (OR 1.82, 95% CI: 1.14, 2.93; all pregnancies per woman). CONCLUSIONS: Light/medium occupational physical activity may have reduced miscarriage risk, while specific occupational characteristics such as crouching may have increased risk in this cohort.

Correlates of pre-pregnancy physical inactivity: results from the pregnancy risk assessment monitoring system.

OBJECTIVES: Evaluate the prevalence of physical inactivity (no physical activity or exercise for 30 min or more at least one day per week) in the 3 months prior to pregnancy in a population-based sample of women and identify individual socio-demographic, personal, health, and behavioral factors predictive of pre-pregnancy physical inactivity. METHODS: In this cross-sectional study, we used data from the Centers for Disease Control and Prevention's Pregnancy Risk Assessment Monitoring System to assess the prevalence of self-reported pre-pregnancy physical activity among 4,069 women who delivered a live birth in 2004 in Maine, North Carolina, or Washington State. We developed a predictive model by using a backward selection approach to building logistic regression models to identify independent predictors of physical inactivity in the 3 months prior to pregnancy among those women who did not meet national recommendations for physical activity (activity more than 5 days per week). RESULTS: Overall, the prevalence of pre-pregnancy physical inactivity was 39.2%. Predictors of physical inactivity prior to pregnancy included higher or lower than normal pre-pregnancy body mass index, lower maternal education level, and a history of previous live births. Women with 12 years of education were particularly likely to be inactive prior to pregnancy (prevalence odds ratio 1.81, 95% confidence interval 1.42, 2.32; compared to women with more than 12 years of education). CONCLUSIONS: Physical inactivity is common among women prior to pregnancy. Information on factors predictive of physical inactivity can be used in the development of clinical activities and public health interventions that aim to reduce the level of physical inactivity among women of reproductive age.

Associations between endogenous sex hormone levels and mammographic and bone densities in premenopausal women.

PURPOSE: Mammographic breast and bone mineral densities (BMD) have been associated with luteal phase hormone concentrations in premenopausal women. We assessed the associations of breast and bone densities with follicular phase hormones and sex hormone binding globulin (SHBG) in premenopausal women, given that follicular phase hormones have been shown to be positively associated with premenopausal breast cancer risk. METHODS: One hundred and ninety-two 40-45-year-old women provided a spot urine and/or blood sample during the follicular phase. Hormone and SHBG concentrations, and bone density were measured and routine mammograms were accessed and digitized to obtain breast density measures. Regression models were fit to assess the associations between hormones and SHBG, and breast and bone densities. RESULTS: Positive associations were observed between percent breast density and SHBG (p trend = 0.02), as well as estradiol (p trend = 0.08), after controlling for body mass index (BMI), number of pregnancies, and breast feeding history. In addition, a statistically significant inverse association was observed between total testosterone and head BMD (p trend = 0.01), after controlling for BMI. CONCLUSIONS: Associations were observed between breast and bone densities, and serum hormone concentrations during the follicular phase of the menstrual cycle.

A case-control study of infant, maternal and perinatal characteristics associated with deformational plagiocephaly.

Deformational plagiocephaly, an abnormal asymmetric flattening of infants' heads, is diagnosed in approximately 10% of infants. The prevalence of plagiocephaly has increased dramatically since 1992 when it was first recommended that infants be placed to sleep in a non-prone position to reduce the risk of sudden infant death syndrome. The authors conducted a case-control study to evaluate associations between plagiocephaly and perinatal characteristics. The authors assessed whether risk factors for plagiocephaly have changed since 1992. Cases were born 1987-2002 in Washington State and diagnosed with plagiocephaly at the Craniofacial Center at Seattle Children's Hospital. Risk factor information was abstracted from birth certificate and hospital discharge data and unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI). Cases (n = 2764) were more likely than controls (n = 13 817) to have been injured at birth (OR 1.4; 95% CI 1.2, 1.7) or diagnosed with a congenital anomaly (OR 2.0; 95% CI 1.8, 2.3). Cases were more likely to have been male, a twin, or small-for-gestational-age. This first large-scale, case-control study of risk factors for plagiocephaly in a U.S. population provides new evidence that birth injuries and congenital anomalies are associated with plagiocephaly risk.

Lifetime occupational history and risk of endometriosis.

OBJECTIVES: Endometriosis is the presence of functioning endometrial glands and stroma outside the uterine cavity, most often in the pelvic peritoneal cavity. Women with endometriosis commonly have dysmenorrhea, dyspareunia, pain, menorrhagia, and/or metrorrhagia. Disease complications can include adhesions, chronic pain, and infertility. In this exploratory case-control study, we investigated the relationship between lifetime occupational history and surgically confirmed endometriosis in a population-based sample. METHODS: We conducted interviews with participants, all reproductive-aged female members of a large health-maintenance organization who were first diagnosed with surgically confirmed endometriosis between April 1, 1996 and March 31, 2001. Interviews were also conducted with randomly selected controls, reproductive-aged female enrollees of the same organization from the same time period. Each reported job was coded using US Census Occupations and Industries codes, and classified into categories. We used unconditional logistic regression to compare having worked in a given job class with never having done so. RESULTS: Our study found that an increased risk of endometriosis was associated with having worked as a flight attendant, service station attendant, or health worker, particularly as a nurse or health aide (flight attendant: odds ratio (OR) 9.80, 95% CI 1.08-89.02; service station attendant: OR 5.77, 95% CI 1.03-32.43; health worker: OR 1.49, 95% CI 1.03-2.15). Income and education did not make a difference in the OR estimates for the occupations examined. CONCLUSIONS: This exploratory study suggested that there might be an associated risk of endometriosis for those women who have worked as a flight attendant, service station attendant, or health worker, particularly a nurse.

Use of multiple failure models in injury epidemiology: a case study of arrest and intimate partner violence recidivism in Seattle, WA.

BACKGROUND: Single-failure survival models are commonly used in injury research. We aimed to demonstrate the application of multiple failure survival models in injury research by measuring the association between arrest and IPV recidivism. METHODS: We used data from a population-based cohort of 5466 male-female couples with a police-reported, male-perpetrated incident of IPV against their female partners that occurred in Seattle, WA during 1999-2001. We estimated the risk of physical and psychological IPV recidivism (separately) for the 12 months following the index event, according to perpetrator arrest or non-arrest for the index event. We used time-dependent extended Cox regression analyses for time-to-first IPV event and Prentice, Williams and Peterson model-based analyses for time-to-multiple IPV events. RESULTS: Arrest was associated with a reduction in time-to-first physical IPV recurrence but was not associated with time-to-first psychological IPV recurrence during the 12-month follow-up. Arrest was associated with a significantly decreased risk of physical and psychological IPV during the 12-month follow-up in the multiple failure models. The association between arrest and lower risk of physical IPV recidivism increased with increasing number of follow-up IPV events. CONCLUSIONS: We found arrest to be a plausible deterrent for recurrent IPV reduction. Our study also illustrates the use of multiple failure survival analyses in injury research. Such techniques facilitate inference about estimands that may have greater public health relevance and properly account for injury recurrence. By using multiple failure models, we were able to more deeply understand the relationship between arrest and IPV over time.

Risk of complex and atypical endometrial hyperplasia in relation to anthropometric measures and reproductive history.

The authors sought to test the hypothesis that characteristics and exposures which influence the balance of estrogen and progesterone bear on the incidence of endometrial hyperplasia (EH), a noninvasive proliferation of the lining of the uterus. Cases included all female members of Group Health (Washington State) who were diagnosed with complex EH or EH with atypia during the period 1985-2003 and whose diagnoses were confirmed in a pathology review (n = 446). Controls were selected randomly from Group Health membership files and were matched to the cases by age and enrollment status at the reference date. An increased risk of EH was associated with increasing body mass index and nulliparity. There was a suggestion of a decreased risk of EH with atypia among current smokers. No association with diabetes or hypertension was found. The risk factors observed to be associated with EH in this study are similar to those associated with endometrial cancer. Whether these risk factors predispose women to cancer simply by increasing EH incidence or continue to augment cancer risk even after EH is present is currently unknown.

Reproductive factors, age at maximum height, and risk of three histologic types of breast cancer.

Numerous studies have evaluated the association between factors related to maturation and reproduction and breast cancer risk, but few have assessed how these factors are related to different histologic types of breast cancer among postmenopausal women. We used polytomous logistic regression to assess the effect of age at maximum height and reproductive factors on risk of invasive breast cancer by histologic type in three case groups (524 ductal, 324 lobular, and 196 ductal-lobular) and 469 controls enrolled in a population-based case-control study of women ages 55 to 74 years residing in the Seattle-Puget Sound region of Washington State (2000-2004). Histologic type was determined by a centralized tissue review for 83% of cases. Age at menarche and age at maximum height were inversely associated with risk of ductal-lobular carcinoma (P(trend) = 0.04 for both exposures) but not ductal or lobular carcinoma. Relative to nulliparous women, parous women had a 50% reduced risk of all histologic types of breast cancer. We observed similar increases in risk across histologic types associated with having a first live birth at ages > or = 30 years compared with ages < or = 19 years. Compared with parous women who never breast-fed, those who breast-fed had a reduced risk of ductal carcinoma (odds ratio, 0.7; 95% confidence interval, 0.5-0.9) but not lobular or ductal-lobular carcinoma. Further exploration of breast cancer risk by histology is merited to understand differences in the etiology of ductal, lobular, and ductal-lobular carcinoma.

Maternal and infant characteristics associated with prone and lateral infant sleep positioning in Washington state, 1996-2002.

OBJECTIVE: To identify factors predictive of either lateral or prone infant sleep positioning. STUDY DESIGN: We used data for 11340 mother-infant pairs from the Pregnancy Risk Assessment Monitoring System for infants born in Washington State, 1996 to 2002. We used predictive modeling to identify statistically significant (P < .05) predictors of lateral and prone sleep positioning. RESULTS: Factors associated with both high-risk sleep positions included infant's year of birth, maternal race and ethnicity, maternal county of residence, and maternal parity. Mother's being US-born (versus foreign-born) and male infant sex were predictive only of prone sleep positioning. Having Medicaid as primary insurance, receipt of government benefits, low infant gestational age, and low birth weight were predictive only of lateral sleep positioning. CONCLUSIONS: Factors predictive of either high-risk sleep position should be considered when devising public health intervention strategies for the prevention of SIDS.

Body mass index and weight gain prior to pregnancy and risk of gestational diabetes mellitus.

OBJECTIVE: The objective of the study was to evaluate obesity and rate of weight change during the 5 years before pregnancy and risk of gestational diabetes mellitus (GDM) in a nested case-control study. STUDY DESIGN: GDM cases (n = 251) and controls (n = 204) were selected from a multiethnic cohort of 14,235 women who delivered a live birth between 1996 and 1998. Women who gained or lost weight were compared with those with a stable weight (+/- 1.0 kg/year). RESULTS: Women who gained weight at a rate of 1.1 to 2.2 kg/year had a small increased risk of GDM (odds ratio [OR] 1.63 [95% confidence interval (CI) 0.95 to 2.81]) and women who gained weight at a rate of 2.3 to 10.0 kg/year had a 2.5-fold increased risk of GDM (OR 2.61 [95% CI, 1.50 to 4.57]), compared with women with stable weight (after adjusting for age, race-ethnicity, parity, and baseline body mass index). CONCLUSION: Weight gain in the 5 years before pregnancy may increase the risk of GDM.

Epidemiology competency development and application to training for local and regional public health practitioners.

In 2002, the Northwest Center for Public Health Practice (NWCPHP) at the University of Washington initiated the Epidemiology Competencies Project, with the goal of developing competency-based epidemiology training for non-epidemiologist public health practitioners in the northwestern United States. An advisory committee consisting of epidemiology faculty and experienced public health practitioners developed the epidemiology competencies. NWCPHP used the competencies to guide the development of in-person trainings, a series of online epidemiology modules, and a Web-based repository of epidemiology teaching materials. The epidemiology competencies provided a framework for collaborative work between NWCPHP and local and regional public health partners to develop trainings that best met the needs of a particular public health organization. Evaluation surveys indicated a high level of satisfaction with the online epidemiology modules developed from the epidemiology competencies. However, measuring the effectiveness of competency-based epidemiology training for expanding epidemiology knowledge and skills of the public health workforce remains a challenge.

Conversational silence, coercion, equality: the role of language in influencing who gets identified as abused.

Various methods of ascertaining self-reported exposure to intimate partner violence (IPV) in health care and research settings have been evaluated to identify women who interpret themselves as abused for clinical and research intervention. However, few interpretive frameworks have been proposed to explain factors that may influence the success of this ascertainment process, including the contribution of language in facilitating women's interpretations of situations as abusive across social, cultural and historical contexts. This omission is substantial, given that IPV is context-specific, involving interaction between individuals of diverse linguistic and cultural backgrounds and their sociocultural environment. In the first part of this paper, we outline hermeneutics, one interpretive theoretical tradition to describe approaches to interpreting IPV. Hermeneutics is a linguistic philosophy that focuses on questions of how people understand spoken language, written text, and themselves through language across sociocultural environments. Hermeneutics acknowledges conditions and situations that facilitate opportunities for broad shared understanding and vocabularies about violence between communities, professionals and abused women, which in turn may reduce harm to women and negotiate action women may want to take in response to situations they interpret as abusive. In the second and third parts of the paper, we compare and contrast the strengths and limitations of three common approaches for asking women about IPV in health care and research settings, and outline a multi-dimensional IPV ascertainment tool that incorporates the three asking approaches to facilitate professionals bringing broad definitions of and vocabularies about abuse to encounters with women. This paper provides health care researchers, clinicians and policy makers with a framework for understanding the potential influence of language on women's interpretations of IPV, including the role of community and professional conversational silence, coercion and equality in influencing women's interpretations. We look at the influence of language about intimate partner violence in the United States on women's interpretations of abuse, although the basic constructs presented here could be applied in other countries and settings.