Theory, methods, and operational results of the Young Women's Health History Study: a study of young-onset breast cancer incidence in Black and White women.

PURPOSE: The etiology of young-onset breast cancer (BC) is poorly understood, despite its greater likelihood of being hormone receptor-negative with a worse prognosis and persistent racial and socioeconomic inequities. We conducted a population-based case-control study of BC among young Black and White women and here discuss the theory that informed our study, exposures collected, study methods, and operational results. METHODS: Cases were non-Hispanic Black (NHB) and White (NHW) women age 20-49 years with invasive BC in metropolitan Detroit and Los Angeles County SEER registries 2010-2015. Controls were identified through area-based sampling from the U.S. census and frequency matched to cases on study site, race, and age. An eco-social theory of health informed life-course exposures collected from in-person interviews, including socioeconomic, reproductive, and energy balance factors. Measured anthropometry, blood (or saliva), and among cases SEER tumor characteristics and tumor tissue (from a subset of cases) were also collected. RESULTS: Of 5,309 identified potentially eligible cases, 2,720 sampled participants were screened and 1,812 completed interviews (682 NHB, 1140 NHW; response rate (RR): 60%). Of 24,612 sampled control households 18,612 were rostered, 2,716 participants were sampled and screened, and 1,381 completed interviews (665 NHB, 716 NHW; RR: 53%). Ninety-nine% of participants completed the main interview, 82% provided blood or saliva (75% blood only), and SEER tumor characteristics (including ER, PR and HER2 status) were obtained from 96% of cases. CONCLUSIONS: Results from the successfully established YWHHS should expand our understanding of young-onset BC etiology overall and by tumor type and identify sources of racial and socioeconomic inequities in BC.

Association between swimming lessons and drowning in childhood: a case-control study.

OBJECTIVE: To estimate the association between swimming lessons and the risk of drowning among children aged 1 to 19 years. DESIGN: Case-control study. SETTING: Cases were identified from medical examiners'/coroners' offices between mid-2003 and mid-2005. Jurisdictions included the states of Maryland and North Carolina, 14 districts (33 counties) in Florida, 3 counties in California, 1 county in Texas, and 1 county in New York. PARTICIPANTS: Cases were children and adolescents aged 1 to 19 years who died of unintentional drowning. Interviews were conducted with 88 families of children who drowned and 213 matched controls. Main Exposure Swimming lessons. Main Outcome Measure Death due to unintentional drowning. Drownings that were intentional, of undetermined intent, or that occurred under conditions in which swimming ability was unlikely to impact risk (eg, in ice water or bathtubs) were excluded. RESULTS: Of the 61 cases in the 1- to 4-year age group, 2 (3%) had participated in formal swimming lessons vs 35 of 134 matched controls (26%) (adjusted odds ratio [OR], 0.12; 95% confidence interval [CI], 0.01-0.97). Among the 27 cases aged 5 to 19 years, 7 (27%) had ever taken formal swimming lessons vs 42 of 79 matched controls (53%) (adjusted OR, 0.36; 95% CI, 0.09-1.51). In adjusted analyses, there was no statistically significant association between informal instruction and drowning risk. CONCLUSIONS: Participation in formal swimming lessons was associated with an 88% reduction in the risk of drowning in the 1- to 4-year-old children, although our estimates were imprecise and 95% CIs included risk reductions ranging from 3% to 99%.

Participation of next of kin in research following sudden, unexpected death of a child.

OBJECTIVE: To assess parents' perceptions of their experience being interviewed after the sudden, unexpected death of their child. DESIGN: Case-control study in which cases were victims of unintentional drowning. SETTING: Households of recent drowning victims in 6 states in the United States. PARTICIPANTS: Caregivers (primarily parents) of 87 cases and 491 matched controls were interviewed via telephone about their child. MAIN EXPOSURE: Recent death of a child by unintentional drowning. MAIN OUTCOME MEASURES: Degree of stress related to interview, perception of interview length, and participants' views about their willingness to participate in this type of interview again, given their experience with the current interview. RESULTS: Although case participants were more likely than controls to perceive the interview as somewhat or very stressful (odds ratio, 3.64; 95% confidence interval, 1.67-7.96), most of the case participants (87.2%) and controls (96.1%) perceived the interview to be not at all or a little stressful. A greater percentage of controls (37.8%) found the interview to be too long, compared with case participants (20.9%). Among case participants, perceived stress during the interview and the perceived length of the interview were not associated with willingness to participate again. Both of these associations were significant (P<.001) for controls. CONCLUSIONS: Caregivers who chose to participate in the study generally rated their experiences as not very stressful. Most of the caregivers indicated that they would be willing to participate again in a similar study.