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Open Access Publications from the University of California

Scholarly Works (97 results)

  • Article
  • Peer Reviewed
UC San Francisco Previously Published Works (2015)
The concept of translational cancer epidemiology has evolved since its early beginnings in 1937 with the establishment of the National Cancer Institute. Conceptual models of cancer control research have also evolved over the last 30 years, to the point where we now have 4 stages of translational research (T0-T4). The current review by Lam et al. (Am J Epidemiol. 2015;181(7):451-458) covers cancer epidemiology research supported by the National Cancer Institute and a selected sample of the cancer epidemiology literature. It suggests that most cancer epidemiology in the last 10 years has been in pure discovery research. Current "drivers" of cancer epidemiology research, including new technologies, team science multilevel research, and knowledge integration, are not strongly represented in the review. However, the use of epidemiology in the latter stages of translation may not have been captured by the scope of this review. The closer epidemiologists get to advanced stages of translation, the more likely they are to work with investigators in other disciplines in other sectors of society. An argument can be made that regardless of whether this kind of research is not happening or was just missed by the current review, the field of cancer epidemiology can expand its scope and further evolve towards more effective applications in population health.
    • Thesis
    • Peer Reviewed
    UC San Francisco Electronic Theses and Dissertations (2017)

    Nearly half of all pregnancies worldwide are unintended (41%).1 Among young women, this number is even higher. By the age of 20, one in three women in the United States will experience a pregnancy,1 and over 80 percent of these will be unintended.2,3 Ensuring that a woman is able to make the right choice for herself about whether to carry an unintended pregnancy to term is fundamental to her health and wellbeing. A woman’s decision to continue or terminate an unintended pregnancy has ramifications that affect her health, her educational, professional and personal aspirations, as well as the health and wellbeing of her children. 4-7 However, methodological limitations in our ability to measure unintended pregnancy and abortion, and our ability to study their causes, limit the effectiveness of interventions designed to improve women’s health.

    The first chapter of my dissertation introduces a novel methodological tool for the measurement of sensitive and stigmatized events: the list experiment. Validation studies suggest that the degree of underreporting of self-reported abortions is high. In countries where abortion is illegal, underreporting may be even greater. But without accurate estimates of the size of the population affected, effective policy and programs cannot be developed or targeted. This chapter describes results from a study of women of reproductive age in Liberia in 2013. To measure abortion prevalence, each woman was read two lists: A) a list of non-sensitive items, and B) a list of correlated non-sensitive items with abortion added. The sensitive item, abortion, was randomly added to either List A or List B for each respondent. The respondent reported a simple count of the options on each list that she had experienced, without indicating which options. Difference in means calculations between the average counts for each list were then averaged to provide an estimate of the population proportion that has had an abortion.

    The second chapter of my dissertation extends the work of the first chapter. I implement two multivariable regression estimators with the list experiment data to understand how age and education vary with history of abortion. We find that education and abortion are inversely associated, after accounting for age. The hope is to encourage other epidemiologists to utilize newly developed tools for multivariable regression estimation with list experiment data.

    The third and final chapter of the dissertation moves from measurement to analysis. The aim of this chapter is to introduce a causal inference framework to the family planning literature. I examine whether social support is causally linked to the incidence of undesired pregnancy among approximately 1,000 young women in Michigan. Using multivariable logistic regression, and an extension using standardization, I calculate relative and absolute estimates of the incidence of undesired pregnancy under two levels of social support.

    As a body of work, my dissertation introduces a novel measurement tool to the field toward the goal of more accurate measurement – a first principle of epidemiology. It also offers a roadmap for how to approach family planning questions with a causal inference framework, to bring new rigor to the field, and improve our understandings of the complex determinants of unplanned pregnancy and abortion.

      Cover page: UNINTENDED PREGNANCY & ABORTION: METHODOLOGICAL INNOVATIONS IN FAMILY PLANNING RESEARCH
      • Article
      • Peer Reviewed
      UC San Francisco Previously Published Works (2017)
      Cancer centers, particularly those supported by the National Cancer Institute, are charged with reducing the cancer burden in their catchment area. However, methods to define both the catchment area and the cancer burden are diverse and range in complexity often based on data availability, staff resources, or confusion about what is required. This article presents a review of the current literature identifying 4 studies that have defined various aspects of the cancer burden in a defined geographical area and highlights examples of how some cancer centers and other health institutions have defined their catchment area and characterized the cancer burden within it. We then present a detailed case study of an approach applied by the University of California, San Francisco, Helen Diller Family Comprehensive Cancer Center to define its catchment area and its population cancer burden. We cite examples of how the Cancer Center research portfolio addresses the defined cancer burden. Our case study outlines a systematic approach to using publicly available data, such as cancer registry data, that are accessible by all cancer centers. By identifying gaps and formulating future research directions based on the needs of the population within the catchment area, epidemiologic studies and other types of cancer research can be directed to the population served. This review can help guide cancer centers in developing an approach to defining their own catchment area as mandated and applying research findings to this defined population.
        Cover page: The Population Burden of Cancer: Research Driven by the Catchment Area of a Cancer Center
        • Thesis
        • Peer Reviewed
        UC San Francisco Electronic Theses and Dissertations (2024)

        Although incidence and mortality rates of colorectal cancer (CRC) in the United States (US) have declined in recent years, all populations have not benefited equally of improvements in screening and treatment. Racial and ethnic minoritized groups, low-income people and uninsured persons face the highest burden of this disease. Recent developments in cancer research have highlighted the need for evaluating neighborhood and social level factors in addition to individual characteristics, as they capture information on access to resources that are key elements of cancer risk. The overarching goal of this dissertation was to evaluate the relationship between the social environment and CRC screening and stage at diagnosis in the US, and to determine the role of public health policy in reducing racial and ethnic disparities.Residential segregation has shaped the history of the US, providing resources and better opportunities to people residing in some neighborhoods, while disinvestment have taken place in other areas (mostly inhabited by Black and other racial and ethnic minoritized groups). On the other hand, with the Medicaid expansion provision of the Patient Protection and Affordable Care Act (ACA), access to health insurance has been facilitated to underserved people. Yet, many states have decided not adopting it. This dissertation used national datasets representative of all areas in the US and a novel measure of residential segregation to capture the social environment of individuals and its association with CRC outcomes (Chapters 1 and 2). This dissertation also evaluated the effect of Medicaid expansion in reducing health inequities after the implementation of the ACA (Chapter 3).

          • Article
          • Peer Reviewed
          UC San Francisco Previously Published Works (2009)

          Objectives

          We introduce and describe the Breast Cancer and the Environment Research Centers (BCERC), a research network with a transdisciplinary approach to elucidating the role of environmental factors in pubertal development as a window on breast cancer etiology. We describe the organization of four national centers integrated into the BCERC network.

          Data sources

          Investigators use a common conceptual framework based on multiple levels of biologic, behavioral, and social organization across the life span. The approach connects basic biologic studies with rodent models and tissue culture systems, a coordinated multicenter epidemiologic cohort study of prepubertal girls, and the integration of community members of breast cancer advocates as key members of the research team to comprise the network.

          Data extraction

          Relevant literature is reviewed that describes current knowledge across levels of organization. Individual research questions and hypotheses in BCERC are driven by gaps in our knowledge that are presented at genetic, metabolic, cellular, individual, and environmental (physical and social) levels.

          Data synthesis

          As data collection on the cohort, animal experiments, and analyses proceed, results will be synthesized through a transdisciplinary approach.

          Conclusion

          Center investigators are addressing a large number of specific research questions related to early pubertal onset, which is an established risk factor for breast cancer. BCERC research findings aimed at the primary prevention of breast cancer will be disseminated to the scientific community and to the public by breast cancer advocates, who have been integral members of the research process from its inception.
            Cover page: The Breast Cancer and the Environment Research Centers: Transdisciplinary Research on the Role of the Environment in Breast Cancer Etiology
            • Article
            • Peer Reviewed
            UC San Francisco Previously Published Works (2020)

            Background

            Technology is being increasingly used to communicate health information, but there is limited knowledge on whether these strategies are effective for vulnerable populations, including non-English speaking or low-income individuals.

            Objective

            This study assessed how language preferences (eg, English, Spanish, or Chinese), smartphone ownership, and the type of clinic for usual source of care (eg, no usual source of care, nonintegrated safety net, integrated safety net, private or community clinic, academic tertiary medical center, or integrated payer-provider) affect technology use for health-related communication.

            Methods

            From May to September 2017, we administered a nonrandom, targeted survey to 1027 English-, Spanish-, and Chinese-speaking San Francisco residents and used weighted multivariable logistic regression analyses to assess predictors of five technology use outcomes. The three primary predictors of interest-language preference, smartphone ownership, and type of clinic for usual care-were adjusted for age, gender, race or ethnicity, limited English proficiency, educational attainment, health literacy, and health status. Three outcomes focused on use of email, SMS text message, or phone apps to communicate with clinicians. The two other outcomes were use of Web-based health videos or online health support groups.

            Results

            Nearly one-third of participants watched Web-based health videos (367/1027, 35.74%) or used emails to communicate with their clinician (318/1027, 30.96%). In adjusted analyses, individuals without smartphones had significantly lower odds of texting their clinician (adjusted odds ratio [aOR] 0.27, 95% CI 0.13-0.56), using online health support groups (aOR 0.14, 95% CI 0.04-0.55), or watching Web-based health videos (aOR 0.31, 95% CI 0.15-0.64). Relative to English-speaking survey respondents, individuals who preferred Chinese had lower odds of texting their clinician (aOR 0.25, 95% CI 0.08-0.79), whereas Spanish-speaking survey respondents had lower odds of using apps to communicate with clinicians (aOR 0.34, 95% CI 0.16-0.75) or joining an online support group (aOR 0.30, 95% CI 0.10-0.92). Respondents who received care from a clinic affiliated with the integrated safety net, academic tertiary medical center, or integrated payer-provider systems had higher odds than individuals without a usual source of care at using emails, SMS text messages, or apps to communicate with clinicians.

            Conclusions

            In vulnerable populations, smartphone ownership increases the use of many forms of technology for health purposes, but device ownership itself is not sufficient to increase the use of all technologies for communicating with clinicians. Language preference impacts the use of technology for health purposes even after considering English proficiency. Health system factors impact patients' use of technology-enabled approaches for communicating with clinicians. No single factor was associated with higher odds of using technology for all health purposes; therefore, existing disparities in the use of digital health tools among diverse and vulnerable populations can only be addressed using a multipronged approach.
              • Article
              • Peer Reviewed
              UC San Francisco Previously Published Works (2017)

              Objective

              Early puberty in girls is linked to some adverse outcomes in adolescence and mid-life. We address two research questions: (1) Are socioeconomic circumstances and ethnicity associated with early onset puberty? (2) Are adiposity and/or psychosocial stress associated with observed associations?

              Design

              Longitudinal data on 5839 girls from the UK Millennium Cohort Study were used to estimate associations between ethnicity, family income, adiposity and psychosocial stress with a marker of puberty.

              Main outcome measure

              Reported menstruation at age 11 years.

              Results

              All quoted ORs are statistically significant. Girls in the poorest income quintile were twice as likely (OR=2.1), and the second poorest quintile nearly twice as likely (OR=1.9) to have begun menstruation compared with girls in the richest income quintile. Estimates were roughly halved on adjustment for Body Mass Index and markers of psychosocial stress (poorest, OR=1.5; second poorest, OR=1.5). Indian girls were over 3 times as likely compared with whites to have started menstruation (OR=3.5) and statistical adjustments did not attenuate estimates. The raised odds of menstruation for Pakistani (OR=1.9), Bangladeshi (OR=3.3) and black African (OR=3.0) girls were attenuated to varying extents, from about a third to a half, on adjustment for income and adiposity.

              Conclusions

              In contemporary UK, excess adiposity and psychosocial stress were associated with social inequalities in early puberty, while material disadvantage and adiposity were linked to ethnic inequalities in early puberty among girls.
                Cover page: Early puberty in 11-year-old girls: Millennium Cohort Study findings
                • Article
                • Peer Reviewed
                UC San Francisco Previously Published Works (2015)
                We examined the effect of smoking on long-term mortality from breast cancer and other causes among a cohort of women with breast cancer. A total of 975 women diagnosed with breast cancer and aged 40-84 years were followed for a median follow-up of 11 years in the U.S. Health and Functioning in Women (HFW) study. The impact of the individual smoking status and smoking intensity reported in the first few months following breast cancer diagnosis on the risk of mortality from breast cancer and other causes was examined using Cox proportional hazards models. In this study, former smoking was associated with increased risk of other-cause mortality (hazard ratio [HR] = 1.47, 95% confidence interval [CI]: 1.13-1.90), and the risk doubled with increased intensity (HR for <50 pack-years [py]: 1.36, 95% CI: 1.03-1.79; HR for ≥50 py: 2.45, 95% CI: 1.41-4.23). Current smoking (HR = 2.45, 95% CI: 1.81-3.32) and each additional 10 py smoked (HR = 1.16, 95% CI: 1.11-1.22) were associated with statistically significant increases in the risk of other-cause mortality. The effect of current smoking on other-cause mortality decreased with advancing stage and increasing body mass index (BMI). Breast cancer-specific mortality was associated with current smoking of ≥50 py (HR = 2.36, 95% CI: 1.26-4.44), and each additional 10 py smoked (HR = 1.07, 95% CI: 1.01-1. 14). Current smoking, but not former smoking, was associated with increased risk of breast cancer-specific mortality in women with local disease (HR = 2.32, 95% CI: 1.32-4.09), but not in those with regional and distant disease (HR = 1.10, 95% CI: 0.73-1.68). Our findings suggest that current smoking at the time of breast cancer diagnosis may be associated with increased risk of breast-cancer specific and other-cause mortality, whereas former smoking is associated with increased risk of other-cause mortality. Smoking cessation at the time of diagnosis may lead to better prognosis among women with breast cancer.
                  • Article
                  • Peer Reviewed
                  UC San Francisco Previously Published Works (2016)

                  Background

                  The relationship of childhood socioeconomic position (SEP) to adult cancer has been inconsistent in the literature and there has been no review summarising the current evidence focused solely on cancer outcomes.

                  Methods and results

                  We performed a rapid review of the literature, which identified 22 publications from 13 studies, primarily in the UK and northern European countries that specifically analysed individual measures of SEP in childhood and cancer outcomes in adulthood. Most of these studies adjusted for adult SEP as a critical mediator of the relationship of interest.

                  Conclusions

                  Results confirm that childhood socioeconomic circumstances have a strong influence on stomach cancer and are likely to contribute, along with adult circumstances, to lung cancer through cumulative exposure to smoking. There was also some evidence of increased risk of colorectal, liver, cervical and pancreatic cancers with lower childhood SEP in large studies, but small numbers of cancer deaths made these estimates imprecise. Gaps in knowledge and potential policy implications are presented.
                    Cover page: Socioeconomic position in childhood and cancer in adulthood: a rapid-review
                    • Article
                    • Peer Reviewed
                    UC San Francisco Previously Published Works (2013)
                    Big data is often discussed in the context of improving medical care, but it also has a less appreciated but equally important role to play in preventing disease. Big data can facilitate action on the modifiable risk factors that contribute to a large fraction of the chronic disease burden, such as physical activity, diet, tobacco use, and exposure to pollution. It can do so by facilitating the discovery of risk factors for disease at population, subpopulation, and individual levels, and by improving the effectiveness of interventions to help people achieve healthier behaviors in healthier environments. In this article, we describe new sources of big data in population health, explore their applications, and present two case studies illustrating how big data can be leveraged for prevention. We also discuss the many implementation obstacles that must be overcome before this vision can become a reality.
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