Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline.

BACKGROUND: Numerous studies demonstrate associations between serum concentrations of 25-hydroxyvitamin D (25[OH]D) and a variety of common disorders, including musculoskeletal, metabolic, cardiovascular, malignant, autoimmune, and infectious diseases. Although a causal link between serum 25(OH)D concentrations and many disorders has not been clearly established, these associations have led to widespread supplementation with vitamin D and increased laboratory testing for 25(OH)D in the general population. The benefit-risk ratio of this increase in vitamin D use is not clear, and the optimal vitamin D intake and the role of testing for 25(OH)D for disease prevention remain uncertain. OBJECTIVE: To develop clinical guidelines for the use of vitamin D (cholecalciferol [vitamin D3] or ergocalciferol [vitamin D2]) to lower the risk of disease in individuals without established indications for vitamin D treatment or 25(OH)D testing. METHODS: A multidisciplinary panel of clinical experts, along with experts in guideline methodology and systematic literature review, identified and prioritized 14 clinically relevant questions related to the use of vitamin D and 25(OH)D testing to lower the risk of disease. The panel prioritized randomized placebo-controlled trials in general populations (without an established indication for vitamin D treatment or 25[OH]D testing), evaluating the effects of empiric vitamin D administration throughout the lifespan, as well as in select conditions (pregnancy and prediabetes). The panel defined "empiric supplementation" as vitamin D intake that (a) exceeds the Dietary Reference Intakes (DRI) and (b) is implemented without testing for 25(OH)D. Systematic reviews queried electronic databases for publications related to these 14 clinical questions. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology was used to assess the certainty of evidence and guide recommendations. The approach incorporated perspectives from a patient representative and considered patient values, costs and resources required, acceptability and feasibility, and impact on health equity of the proposed recommendations. The process to develop this clinical guideline did not use a risk assessment framework and was not designed to replace current DRI for vitamin D. RESULTS: The panel suggests empiric vitamin D supplementation for children and adolescents aged 1 to 18 years to prevent nutritional rickets and because of its potential to lower the risk of respiratory tract infections; for those aged 75 years and older because of its potential to lower the risk of mortality; for those who are pregnant because of its potential to lower the risk of preeclampsia, intra-uterine mortality, preterm birth, small-for-gestational-age birth, and neonatal mortality; and for those with high-risk prediabetes because of its potential to reduce progression to diabetes. Because the vitamin D doses in the included clinical trials varied considerably and many trial participants were allowed to continue their own vitamin D-containing supplements, the optimal doses for empiric vitamin D supplementation remain unclear for the populations considered. For nonpregnant people older than 50 years for whom vitamin D is indicated, the panel suggests supplementation via daily administration of vitamin D, rather than intermittent use of high doses. The panel suggests against empiric vitamin D supplementation above the current DRI to lower the risk of disease in healthy adults younger than 75 years. No clinical trial evidence was found to support routine screening for 25(OH)D in the general population, nor in those with obesity or dark complexion, and there was no clear evidence defining the optimal target level of 25(OH)D required for disease prevention in the populations considered; thus, the panel suggests against routine 25(OH)D testing in all populations considered. The panel judged that, in most situations, empiric vitamin D supplementation is inexpensive, feasible, acceptable to both healthy individuals and health care professionals, and has no negative effect on health equity. CONCLUSION: The panel suggests empiric vitamin D for those aged 1 to 18 years and adults over 75 years of age, those who are pregnant, and those with high-risk prediabetes. Due to the scarcity of natural food sources rich in vitamin D, empiric supplementation can be achieved through a combination of fortified foods and supplements that contain vitamin D. Based on the absence of supportive clinical trial evidence, the panel suggests against routine 25(OH)D testing in the absence of established indications. These recommendations are not meant to replace the current DRIs for vitamin D, nor do they apply to people with established indications for vitamin D treatment or 25(OH)D testing. Further research is needed to determine optimal 25(OH)D levels for specific health benefits.

The electronic health record Risk of Alzheimer's and Dementia Assessment Rule (eRADAR) Brain Health Trial: Protocol for an embedded, pragmatic clinical trial of a low-cost dementia detection algorithm.

BACKGROUND: About half of people living with dementia have not received a diagnosis, delaying access to treatment, education, and support. We previously developed a tool, eRADAR, which uses information in the electronic health record (EHR) to identify patients who may have undiagnosed dementia. This paper provides the protocol for an embedded, pragmatic clinical trial (ePCT) implementing eRADAR in two healthcare systems to determine whether an intervention using eRADAR increases dementia diagnosis rates and to examine the benefits and harms experienced by patients and other stakeholders. METHODS: We will conduct an ePCT within an integrated healthcare system and replicate it in an urban academic medical center. At primary care clinics serving about 27,000 patients age 65 and above, we will randomize primary care providers (PCPs) to have their patients with high eRADAR scores receive targeted outreach (intervention) or usual care. Intervention patients will be offered a "brain health" assessment visit with a clinical research interventionist mirroring existing roles within the healthcare systems. The interventionist will make follow-up recommendations to PCPs and offer support to newly-diagnosed patients. Patients with high eRADAR scores in both study arms will be followed to identify new diagnoses of dementia in the EHR (primary outcome). Secondary outcomes include healthcare utilization from the EHR and patient, family member and clinician satisfaction assessed through surveys and interviews. CONCLUSION: If this pragmatic trial is successful, the eRADAR tool and intervention could be adopted by other healthcare systems, potentially improving dementia detection, patient care and quality of life.

LungCARE: Encouraging Shared Decision-Making in Lung Cancer Screening-a Randomized Trial.

BACKGROUND: Lung cancer screening (LCS) is recommended for individuals at high risk due to age and smoking history after a shared decision-making conversation. However, little is known about best strategies for incorporating shared decision-making, especially in a busy primary care setting. OBJECTIVE: To develop a novel tool, Lung Cancer Assessment of Risk and Education (LungCARE) to guide LCS decisions among eligible primary care patients. DESIGN: Pilot cluster randomized controlled trial of LungCARE versus usual care. PARTICIPANTS: Patients of providers in a university primary care clinic, who met criteria for LCS. INTERVENTION: Providers were randomized to LungCARE intervention or control. LungCARE participants completed a computer tablet-based video assessment of lung cancer educational needs in the waiting room prior to a primary care visit. Patient and provider both received a summary handout of patient concerns and responses. MAIN MEASURES: All eligible patients completed baseline interviews by telephone. One week after the index visit, participants completed a follow-up telephone survey that assessed patient-physician discussion of LCS, referral to and scheduling of LCS, as well as LCS knowledge and acceptability of LungCARE. Two months after index visit, we reviewed patients' electronic health records (EHRs) for evidence of a shared decision-making conversation and referral to and receipt of LCS. KEY RESULTS: A total of 66 participants completed baseline and follow-up visits (34: LungCARE; 32: usual care). Mean age was 65.9 (± 6.0). Based on EHR review, compared to usual care, LungCARE participants were more likely to have discussed LCS with their physicians (56% vs 25%; p = 0.04) and to be referred to LCS (44% vs 13%; p < 0.02). Intervention participants were also more likely to complete LCS (32% vs 13%; p < 0.01) and had higher knowledge scores (mean score 6.5 (± 1.7) vs 5.5 (± 1.4; p < 0.01). CONCLUSIONS: LungCARE increased discussion, referral, and completion of LCS and improved LCS knowledge. CLINICAL TRIAL REGISTRATION: NCT03862001.

Efficacy of a Primary Care-Based Mobile Application to Increase Hepatitis C Screening Among Asian Americans: A Secondary Analysis of a Randomized Clinical Trial.

Background: Hepatitis C virus (HCV) screening remains suboptimal. We assessed the efficacy of a mobile application and provider alert in enhancing HCV screening among Asian Americans. Methods: A secondary analysis of a cluster-randomized clinical trial was performed during the birth cohort screening era to assess the efficacy of a Hepatitis App (intervention), a multilingual mobile application delivering interactive video education on viral hepatitis and creating a Provider Alert printout, at primary care clinics within 2 healthcare systems in San Francisco from 2015 to 2017. A comparison group received usual care and a similar intervention on nutrition and physical activity. The outcome was electronic health record (EHR) documentation of HCV screening along with patient-provider communication about testing and test ordering. Results: Four hundred fifty-two participants (mean age 57 years, 36% male, 80% foreign-born) were randomized by provider clusters to the intervention (n = 270) or comparison groups (n = 182). At 3-month follow up, the intervention group was more likely than the comparison group to be aware of HCV (75% vs 59%, P = .006), to discuss HCV testing with their providers (63% vs 13%, P < .001), to have HCV testing ordered (39% vs 10%, P < .001), and to have EHR-verified HCV testing (30% vs 6%, P < .001). Within the intervention group, being born between 1945 and 1965 (odds ratio, 3.15; 95% confidence interval, 1.35-7.32) was associated with increased HCV testing. Conclusions: The Hepatitis App delivered in primary care settings was effective in increasing HCV screening in a socioeconomically diverse Asian American cohort. This highlights the importance of mobile technology as a patient-centered strategy to address gaps in HCV care.

Barriers and Facilitators to Lung Cancer Screening: A Physician Survey.

PURPOSE: To describe barriers to lung cancer screening (LCS) among family medicine and general internal medicine primary care physicians (PCPs) and assess the association of barriers with discussion and referral for screening. DESIGN: Cross-sectional survey. SUBJECTS AND SETTINGS: Random sample of primary care physicians (PCPs) in California. MEASURES: PCP practices for discussion and referral for LCS and ratings of LCS barriers. ANALYSIS: We performed exploratory factor analysis to identify four barrier constructs: (1) Physician Visit-Level Barriers to screening referral; (2) Physician System and Evidence Barriers; (3) Patient Cost Barrier; and (4) Other Patient Barriers. We then performed multivariable logistic regression adjusted for physician and practice characteristics to assess the association between the physician-reported barriers and whether PCPs discussed or referred for LCS. RESULTS: 368 physicians responded (response rate 42%). Most worked in large metropolitan areas (80%) and large health systems (59%). After adjusting for physician and practice characteristics, we found that physician-reporting of System and Evidence Barriers was associated with lower odds of discussion or referral for LDCT (aOR .18, 95% CI 0.09-0.37), while physician-reported Visit-Level Barriers were associated with increased odds discussion or referral (aOR 2.65, 95% CI 1.30-5.04). CONCLUSIONS: While physicians reported numerous barriers to LCS, we found that barriers were differentially associated with discussion or referral for screening. As new LCS guidelines broaden screening eligibility, it is critical to address these barriers to achieve higher rates of evidence-based LCS.

Health Within Reach-a Patient-Centered Intervention to Increase Hepatitis B Screening Among Asian Americans: a Randomized Clinical Trial.

BACKGROUND: There are few studies to date of interventions to increase viral hepatitis screening among Asian Americans, who have high rates of chronic hepatitis B (HBV) infection. OBJECTIVE: To develop, implement, and test the efficacy of a mobile application (Hepatitis App) delivered in four languages to increase HBV screening among Asian Americans. DESIGN: Cluster-randomized clinical trial. PARTICIPANTS: Four hundred fifty-two Asian American patients ≥ 18 years of age, who had no prior HBV testing, and received primary care within two healthcare systems in San Francisco, CA. INTERVENTIONS: The intervention group received the Hepatitis App, delivering interactive video education on viral hepatitis in English, Cantonese, Mandarin, or Vietnamese and a provider printout (Provider Alert) and Provider Panel Notification. The comparison group received a mobile application delivering nutrition and physical activity education and Provider Panel Notification. MAIN MEASURES: Primary outcomes were patient-provider discussion about HBV and documentation of a HBV screening test within 3 months post-intervention. Secondary outcome was documentation of an order for a HBV screening test. KEY RESULTS: Participants had a mean age of 57 years and were 64% female, 80% foreign-born, and 44% with limited English fluency. At post-visit, over 80% of intervention participants reported they liked using the Hepatitis App. At 3-month follow-up, the intervention group was more likely than the comparison group (all P < 0.001) to have discussed HBV with their provider (70% vs.16%), have a HBV test ordered (44% vs.10%), and receive a HBV test (38% vs.8%). In multivariable analyses, the intervention odds ratio for HBV test ordering was 7.6 (95% CI: 3.9, 14.8) and test receipt was 7.5 (95% CI: 3.6, 15.5). CONCLUSIONS: A multi-lingual educational intervention using a mobile application in primary care clinics was well received by Asian American patients, enhanced patient-provider communication about HBV, and increased HBV screening. Technology can improve healthcare quality among Asian Americans. TRIAL REGISTRATION: ClinicalTrials.gov NCT02139722 ( https://clinicaltrials.gov/ct2/show/NCT02139722 ).

The Effectiveness and Value of Oral Immunotherapy and Viaskin Peanut for Peanut Allergy.

DISCLOSURES: Funding for this summary was contributed by Arnold Ventures, Commonwealth Fund, California Health Care Foundation, National Institute for Health Care Management (NIHCM), New England States Consortium Systems Organization, Blue Cross Blue Shield of Massachusetts, Harvard Pilgrim Health Care, Kaiser Foundation Health Plan, and Partners HealthCare to the Institute for Clinical and Economic Review (ICER), an independent organization that evaluates the evidence on the value of health care interventions. ICER's annual policy summit is supported by dues from Aetna, America's Health Insurance Plans, Anthem, Allergan, Alnylam, AstraZeneca, Biogen, Blue Shield of CA, Cambia Health Services, CVS, Editas, Express Scripts, Genentech/Roche, GlaxoSmithKline, Harvard Pilgrim, Health Care Service Corporation, Health Partners, Johnson & Johnson (Janssen), Kaiser Permanente, LEO Pharma, Mallinckrodt, Merck, Novartis, National Pharmaceutical Council, Premera, Prime Therapeutics, Regeneron, Sanofi, Spark Therapeutics, and United Healthcare. Herron-Smith and Pearson are employed by ICER, which has a contract with the University of California, San Francisco, to perform work for these analyses. Segal was employed by ICER at the time of this review. Tice and Walsh are employed by the University of California, San Francisco. Gazauskas and Hansen have nothing to disclose.

The Effectiveness and Value of Biologic Therapies for the Treatment of Uncontrolled Asthma.

DISCLOSURES: Funding for this summary was contributed by the Laura and John Arnold Foundation, Blue Shield of California, and California Health Care Foundation to the Institute for Clinical and Economic Review (ICER), an independent organization that evaluates the evidence on the value of health care interventions. ICER's annual policy summit is supported by dues from Aetna, AHIP, Anthem, Blue Shield of California, CVS Caremark, Express Scripts, Harvard Pilgrim Health Care, Cambia Health Solutions, United Healthcare, Kaiser Permanente, Premera Blue Cross, AstraZeneca, Genentech, GlaxoSmithKline, Johnson & Johnson, Merck, National Pharmaceutical Council, Prime Therapeutics, Sanofi, Spark Therapeutics, Health Care Service Corporation, Editas, Alnylam, Regeneron, Mallinkrodt, Biogen, HealthPartners, and Novartis. Synnott, Kumar, Adair, Rind, and Pearson are employees of ICER, which provided grants to the University of California, San Francisco, and the University of Colorado to perform work for these analyses. Tice and Walsh are employed by the University of California, San Francisco, and Campbell and Whittington are employed by the University of Colorado.

Women's health 2016: An update for internists.

Internists are called upon on a daily basis to address a range of women's health issues. Staying up to date with the evidence in this wide field can be challenging. This article reviews important studies published in 2015 and early 2016 pertinent to urinary tract infection, osteoporosis, ovarian cancer screening, and contraception.

HPV Update: Vaccination, Screening, and Associated Disease.

Human papillomavirus (HPV) infection is the causative agent in cervical cancer, and is associated with numerous other genital cancers, including vulvar, vaginal, and anal cancer. Primary prevention with HPV vaccination is safe and efficacious, and a recently approved HPV vaccine will provide even more extensive protection against several oncogenic HPV strains. Screening strategies for HPV are rapidly evolving, reflecting the essential role that HPV infection plays in cervical cancer. This article highlights new evidence regarding the efficacy of the recently approved 9-valent HPV (9vHPV) vaccine and the use of primary high-risk HPV testing in cervical cancer screening. We consider the utility of urinary HPV testing in routine clinical practice and review current guidelines regarding anal HPV screening.

Value of Genetic Testing for Hereditary Colorectal Cancer in a Probability-Based US Online Sample.

BACKGROUND: . While choices about genetic testing are increasingly common for patients and families, and public opinion surveys suggest public interest in genomics, it is not known how adults from the general population value genetic testing for heritable conditions. We sought to understand in a US sample the relative value of the characteristics of genetic tests to identify risk of hereditary colorectal cancer, among the first genomic applications with evidence to support its translation to clinical settings. METHODS: . A Web-enabled choice-format conjoint survey was conducted with adults age 50 years and older from a probability-based US panel. Participants were asked to make a series of choices between 2 hypothetical blood tests that differed in risk of false-negative test, privacy, and cost. Random parameters logit models were used to estimate preferences, the dollar value of genetic information, and intent to have genetic testing. RESULTS: . A total of 355 individuals completed choice-format questions. Cost and privacy were more highly valued than reducing the chance of a false-negative result. Most (97% [95% confidence interval (CI)], 95%-99%) would have genetic testing to reduce the risk of dying of colorectal cancer in the best scenario (no false negatives, results disclosed to primary care physician). Only 41% (95% CI, 25%-57%) would have genetic testing in the worst case (20% false negatives, results disclosed to insurance company). CONCLUSIONS: . Given the characteristics and levels included in the choice, if false-negative test results are unlikely and results are shared with a primary care physician, the majority would have genetic testing. As genomic services become widely available, primary care professionals will need to be increasingly knowledgeable about genetic testing decisions.

Fetal aneuploidy detection by maternal plasma DNA sequencing: a technology assessment.

The American College of Obstetricians and Gynecologists currently recommends that all pregnant women be offered screening for chromosomal abnormalities, regardless of maternal age. Traditional screening tests have detection rates ranging from 85% to 90% and false-positive rates of 3% to 5%. A woman with an abnormal noninvasive test is offered a diagnostic test, but diagnostic tests are associated with a risk of pregnancy loss. Recently, analysis of cell-free fetal DNA (cffDNA) in maternal blood has been shown to have potential for the accurate detection of some of the common fetal autosomal aneuploidies. As part of a technology assessment for the California Technology Assessment Forum, we critically reviewed the evidence for the use of cffDNA as a prenatal screening test. We evaluated the evidence for its use as either a 'primary' or an 'advanced' screening test and for its use in screening for three different trisomies: 21, 18, and 13. We evaluated whether the use of cffDNA met established technology assessment criteria and established conclusions about evidence-based use of this new technology.

Effectiveness and reach of the FLU-FIT program in an integrated health care system: a multisite randomized trial.

OBJECTIVES: We tested the effectiveness of offering home fecal immunochemical tests (FITs) during influenza vaccination clinics to increase colorectal cancer screening (CRCS). METHODS: In a clinical trial at Kaiser Permanente Northern California influenza clinics in Redwood City, Richmond, South San Francisco, Union City, and Fresno, we randomly assigned influenza clinic dates to intervention (FIT offered) or control (FIT not offered) and compared subsequent CRCS activity. RESULTS: Clinic staff provided FITs to 53.9% (1805/3351) of intervention patients aged 50 to 75 years. In the intent-to-treat analysis, 26.9% (900/3351) and 11.7% (336/2884) of intervention and control patients completed an FIT, respectively, within 90 days of vaccination (P ≤ .001). The adjusted odds ratio for completing FIT in the intervention versus the control arm was 2.75 (95% confidence interval = 2.40, 3.16). In the per protocol analysis, 35.4% (648/1830) of patients given FIT and 13.3% (588/4405) of patients not given FIT completed FIT within 90 days of vaccination (P ≤ .001). CONCLUSIONS: This intervention may increase CRCS among those not reached by other forms of CRCS outreach. Future research should include the extent to which these programs can be disseminated and implemented nationally.

Colorectal cancer screening: what do women from diverse ethnic groups want?

BACKGROUND: Little is known about factors associated with willingness to undergo colorectal cancer (CRC) screening for personal or public health benefit among women from diverse race/ethnic groups. OBJECTIVE: To evaluate factors associated with willingness to undergo CRC screening for personal and public health benefit among women from diverse race/ethnic groups. METHODS: We interviewed women aged 50 to 80 from four racial/ethnic groups from primary care clinics in 2003-2005. We asked about demographics, CRC screening knowledge and history, perceived risk of colon cancer, and about the outcomes of intention to be screened for personal benefit and for public health benefit. RESULTS: Of the 492 women who completed the interview, 32 % were White, 16 % were African American, 21 % were Latina and 32 % were Asian. Up-to-date screening was reported by 77 % of women, with similar numbers obtaining fecal occult blood test (FOBT) within 2 years or colonoscopy within 10 years. The majority of women were "likely or very likely" to get FOBT or colonoscopy after learning the benefits and risks. Multivariate models showed that compared to Whites, fewer Asians would undergo colonoscopy (OR = 0.28; 95 % CI: 0.12, 0.63), while more Latinas would undergo colonoscopy (OR = 6.14; 95 % CI: 1.77, 21.34) and obtain regular CRC screening (OR = 4.47; 95 % CI: 1.66, 12.04). The majority would obtain CRC screening even if they would not personally benefit; those who perceived themselves to be at higher than average cancer risk were more likely to participate in CRC screening for public health benefit (OR = 2.32; 95 % CI: 1.32, 4.09). CONCLUSIONS: The majority of women are willing to undergo screening for personal benefit. Asians were less likely, and Latinas more likely, to accept colonoscopy. Most are also willing to undergo screening for public health benefit. Self-perceived risk of CRC was the most consistent predictor of willingness and intention to be screened for either personal or public health benefit.

PRE-VIEW: Development and Pilot Testing of An Interactive Video Doctor Plus Provider Alert to Increase Cancer Screening.

BACKGROUND: Interventions to increase recommended cancer screening tests and discussions are needed. METHODS: We developed PRE-VIEW (The PREventive VIdeo Education in Waiting Rooms Program), a multimedia cancer prevention intervention for primary care clinics based on the Transtheoretical Model of Behavior Change We pilot tested PRE-VIEW An Interactive Video Doctor plus Provider Alert for feasibility and acceptability in primary care clinic settings in the San Francisco Bay Area, California in 2009-2010. RESULTS: Eighty participants (33 men and 47 women; more than half non-white) at 5 primary care clinics were included. After PRE-VIEW, 87% of women were definitely interested in mammography when due and 77% were definitely interested in a Pap test. 73% of participants were definitely interested in colorectal cancer screening when due, and 79% of men were definitely interested in a discussion about the PSA test. The majority indicated that they received an appropriate amount of information from PRE-VIEW and that the information presented helped them decide whether or not to be screened. CONCLUSIONS: PRE-VIEW was well received and accepted and potentially provides an innovative and practical way to support physicians' efforts to increase cancer screening.

The FLU-FOBT Program in community clinics: durable benefits of a randomized controlled trial.

The objective of the study was to determine the extent to which the FLU-FOBT Program, a colorectal cancer screening (CRCS) intervention linking the provision of fecal occult blood tests (FOBT) to the time of annual influenza vaccination, resulted in practice changes in six primary care clinics 1 year after it was introduced in a randomized controlled trial (RCT). We assessed CRCS rate changes for influenza vaccine recipients, administered brief serial clinic staff surveys and interviewed clinic leaders 1 year after the RCT. CRCS rates for influenza vaccination recipients between the ages of 50 and 75 years were 42.5% before the RCT, 54.5% immediately after the RCT and 55.8% 1 year after the RCT (P < 0.001 for difference between baseline and 1 year after RCT). Many FLU-FOBT Program components were maintained in most clinics at 1-year follow-up. Only 63% of clinic staff survey respondents (26 of 41) continued offering FOBT with influenza vaccines, but 85% (35 of 41) continued to provide mailing kits with FOBT. Many patient education materials were maintained and staff satisfaction with the intervention remained high. Clinic leaders acknowledged barriers to maintenance but also observed several beneficial practice changes. Many components of the FLU-FOBT Program were maintained, with beneficial outcomes for participating practices.

Willingness to use tamoxifen to prevent breast cancer among diverse women.

Use of chemoprevention to prevent development of breast cancer among high-risk women has been limited despite clinical evidence of its benefit. Our goals were to determine whether knowledge of the benefits and risks of tamoxifen affects a woman's willingness to take it to prevent breast cancer, to define factors associated with willingness to take tamoxifen, and to evaluate race/ethnic differences. Women, ages 50-80, who identified as African American, Asian, Latina, or White, and who had at least one visit to a primary care physician in the previous 2 years, were recruited from ambulatory practices. After a screening telephone survey, women completed an in-person interview in their preferred language. Multivariate regression models were constructed to examine the associations of demographic characteristics, numeracy, breast cancer history, and health knowledge with willingness to take tamoxifen. Over 40% of the women reported they would likely take tamoxifen if determined to be at high risk, and 31% would be somewhat likely to do so. Asian women, those with no insurance, and those with less than high school education were significantly more likely to be willing to take tamoxifen. Higher scores on numeracy and on breast cancer knowledge were also associated with willingness to take tamoxifen. A higher tamoxifen knowledge score was inversely related to willingness to take the drug. Factors affecting women's willingness to take breast cancer chemoprevention drugs vary and are not determined solely by knowledge of risk/benefit or risk perception.