Diana M. Tordoff, PhD, MPH is a postdoctoral scholar with The PRIDE Study ( at the Stanford School of Medicine. She is an epidemiologist whose research focuses on LGBTQ+ health equity. Prior to joining The PRIDE Study, Diana was awarded an NIH Kirschstein National Research Service Fellowship for her doctoral dissertation, which examined the heterogeneity in HIV/STI prevalence, testing, and PrEP use among transgender and non-binary people and their partners in the US. Her interests include barriers and facilitators of healthcare access for LGBTQ+ communities, sexual and reproductive health, molecular epidemiology, the vaginal microbiome, and community-engaged research methods.

Honors & Awards

  • Mentored Research Scientist Career Development Award (K01AI182507), National Institutes of Allergy and Infectious Diseases (2024-2029)
  • Ruth L. Kirschstein National Research Service Award Individual Predoctoral Fellowship (F31AI152542), National Institutes of Allergy and Infectious Diseases (2020-2022)

All Publications

  • A Quantitative Intersectionality Analysis of HIV/STI Prevention and Healthcare Access Among Transgender and Nonbinary People. Epidemiology (Cambridge, Mass.) Tordoff, D. M., Fernandez, A., Perry, N. L., Heberling, W. B., Minalga, B., Khosropour, C. M., Glick, S. N., Barbee, L. A., Duerr, A. 2023; 34 (6): 827-837


    Transgender and nonbinary people experience substantial barriers to accessing healthcare, including prevention of HIV and other sexually transmitted infections (HIV/STI), due to structural inequities. We examined differences in insurance, HIV/STI prevalence, testing, and preexposure prophylaxis use among transgender and nonbinary people living in Washington State by race and ethnicity and gender.We pooled data from five 2019-2021 Washington State HIV/STI surveillance data sources to obtain a large and diverse sample of 1648 transgender and nonbinary participants. We calculated the risk difference (RD) for each outcome and used Poisson regression to estimate a surrogate measure of additive interaction-attributable proportion (AP)-that measures the proportion of the excess prevalence of the outcome observed at the intersection of gendered and racialized experience, beyond that expected from gender or race and ethnicity alone.Participants reported overall high levels of poverty (29% incomes <$15,000 and 7% unstable housing). Certain groups, especially racial/ethnic minority transgender women, were disproportionately impacted by HIV/STIs (RDs from 20% to 43% and APs from 50% to 85%) and less likely to currently have insurance (RDs from 25% to 39% and APs from 74% to 93%) than that expected based on gendered or racialized experience alone.Our findings highlight the heterogeneity in insurance access, HIV/STI positivity, and prevention utilization within transgender communities. We observed that a large proportion of increased HIV/STI prevalence among racial/ethnic minority transgender women was attributable to the intersection of gender and race and ethnicity. Our findings highlight the importance of trans-inclusive models of HIV/STI prevention that address multilevel barriers rooted in cissexism and structural racism.

    View details for DOI 10.1097/EDE.0000000000001669

    View details for PubMedID 37756272

    View details for PubMedCentralID PMC10539029

  • Testosterone Use and Sexual Function among Transgender Men and Gender Diverse People Assigned Female at Birth. American journal of obstetrics and gynecology Tordoff, D. M., Lunn, M. R., Chen, B., Flentje, A., Dastur, Z., Lubensky, M. E., Capriotti, M., Obedin-Maliver, J. 2023


    Testosterone use among transgender people likely impacts their experience of sexual function and vulvovaginal pain via several complex pathways. Testosterone use is associated with decreased estrogen in the vagina and atrophic vaginal tissue, which may be associated with decreased vaginal lubrication and/or discomfort during sexual activity. At the same time, increased gender affirmation through testosterone use may be associated with improved sexual function. However, data on pelvic and vulvovaginal pain among transgender men and nonbinary people assigned female at birth is scarce.To assess the association between testosterone and sexual function, with a focus on symptoms that are commonly associated with vaginal atrophy.We conducted a cross-sectional analysis of 1,219 participants ages 18-72 years old using 2019-2021 data from an online, prospective, longitudinal, cohort study of sexual and/or gender minority people in the US (The PRIDE Study). Our analysis included adult transgender men and gender diverse participants assigned female at birth who were categorized as never, current, and former testosterone users. Sexual function was measured across eight Patient-Reported Outcomes Measurement Information System (PROMIS) Sexual Function and Satisfaction (SexFS) domains.Overall, 516 (42.3%) had never used testosterone and 602 (49.4%) currently used testosterone. Median duration of use was 37.7 months (range 7 days to >27 years). Most participants (64.6%) reported genital pain/discomfort during sexual activity in the past 30 days, most commonly in the vagina/frontal genital opening (52.2%), followed by the clitoris (29.1%) and labia (24.5%). Current testosterone use was associated with higher interest in sexual activity (β=6.32, 95% CI: 4.91-7.74) and more vaginal pain/discomfort during sexual activity (β=1.80, 95% CI: 0.61-3.00). No associations were observed between current testosterone use and satisfaction with sex life, lubrication, labial pain/discomfort, or orgasm pleasure.Testosterone use among transgender men and gender diverse people was associated with a higher interest in sexual activity and ability to orgasm as well as vaginal pain/discomfort during sexual activity. Notably, the available evidence demonstrates that >60% of transgender men experience vulvovaginal pain during sexual activity. The causes of pelvic and vulvovaginal pain are poorly understood but are likely multifactorial and include physiological (e.g., testosterone-associated vaginal atrophy) and psychological factors (e.g., gender affirmation). Given this high burden, there is an urgent need to identify effective and acceptable interventions for this population.

    View details for DOI 10.1016/j.ajog.2023.08.035

    View details for PubMedID 37678647

  • Mental Health Outcomes in Transgender and Nonbinary Youths Receiving Gender-Affirming Care. JAMA network open Tordoff, D. M., Wanta, J. W., Collin, A., Stepney, C., Inwards-Breland, D. J., Ahrens, K. 2022; 5 (2): e220978


    Transgender and nonbinary (TNB) youths are disproportionately burdened by poor mental health outcomes owing to decreased social support and increased stigma and discrimination. Although gender-affirming care is associated with decreased long-term adverse mental health outcomes among these youths, less is known about its association with mental health immediately after initiation of care.To investigate changes in mental health over the first year of receiving gender-affirming care and whether initiation of puberty blockers (PBs) and gender-affirming hormones (GAHs) was associated with changes in depression, anxiety, and suicidality.This prospective observational cohort study was conducted at an urban multidisciplinary gender clinic among TNB adolescents and young adults seeking gender-affirming care from August 2017 to June 2018. Data were analyzed from August 2020 through November 2021.Time since enrollment and receipt of PBs or GAHs.Mental health outcomes of interest were assessed via the Patient Health Questionnaire 9-item (PHQ-9) and Generalized Anxiety Disorder 7-item (GAD-7) scales, which were dichotomized into measures of moderate or severe depression and anxiety (ie, scores ≥10), respectively. Any self-report of self-harm or suicidal thoughts over the previous 2 weeks was assessed using PHQ-9 question 9. Generalized estimating equations were used to assess change from baseline in each outcome at 3, 6, and 12 months of follow-up. Bivariate and multivariable logistic models were estimated to examine temporal trends and investigate associations between receipt of PBs or GAHs and each outcome.Among 104 youths aged 13 to 20 years (mean [SD] age, 15.8 [1.6] years) who participated in the study, there were 63 transmasculine individuals (60.6%), 27 transfeminine individuals (26.0%), 10 nonbinary or gender fluid individuals (9.6%), and 4 youths who responded "I don't know" or did not respond to the gender identity question (3.8%). At baseline, 59 individuals (56.7%) had moderate to severe depression, 52 individuals (50.0%) had moderate to severe anxiety, and 45 individuals (43.3%) reported self-harm or suicidal thoughts. By the end of the study, 69 youths (66.3%) had received PBs, GAHs, or both interventions, while 35 youths had not received either intervention (33.7%). After adjustment for temporal trends and potential confounders, we observed 60% lower odds of depression (adjusted odds ratio [aOR], 0.40; 95% CI, 0.17-0.95) and 73% lower odds of suicidality (aOR, 0.27; 95% CI, 0.11-0.65) among youths who had initiated PBs or GAHs compared with youths who had not. There was no association between PBs or GAHs and anxiety (aOR, 1.01; 95% CI, 0.41, 2.51).This study found that gender-affirming medical interventions were associated with lower odds of depression and suicidality over 12 months. These data add to existing evidence suggesting that gender-affirming care may be associated with improved well-being among TNB youths over a short period, which is important given mental health disparities experienced by this population, particularly the high levels of self-harm and suicide.

    View details for DOI 10.1001/jamanetworkopen.2022.0978

    View details for PubMedID 35212746

    View details for PubMedCentralID PMC8881768

  • Misclassification of Sex Assigned at Birth in the Behavioral Risk Factor Surveillance System and Transgender Reproductive Health: A Quantitative Bias Analysis. Epidemiology (Cambridge, Mass.) Tordoff, D., Andrasik, M., Hajat, A. 2019; 30 (5): 669-678


    National surveys based on probability sampling methods, such as the Behavioral Risk Factor and Surveillance System (BRFSS), are crucial tools for unbiased estimates of health disparities. In 2014, the BRFSS began offering a module to capture transgender and gender nonconforming identity. Although the BRFSS provides much needed data on the this population, these respondents are vulnerable to misclassification of sex assigned at birth.We applied quantitative bias analysis to explore the magnitude and direction of the systematic bias present as a result of this misclassification. We use multivariate Poisson regression with robust standard errors to estimate the association between gender and four sex-specific outcomes: prostate-specific antigen testing, Pap testing, hysterectomy, and pregnancy. We applied single and multiple imputation methods, and probabilistic adjustments to explore bias present in these estimates.Combined BRFSS data from 2014, 2015, and 2016 included 1078 transgender women, 701 transgender men, and 450 gender nonconforming individuals. Sex assigned at birth was misclassified among 29.6% of transgender women and 30.2% of transgender men. Transgender and gender nonconforming individuals excluded due to sex-based skip patterns are demographically distinct from those who were asked reproductive health questions, suggesting that there is noteworthy selection bias present in the data. Estimates for gender nonconforming respondents are vulnerable to small degrees of bias, while estimates for cancer screenings among transgender women and men are more robust to moderate degrees of bias.Our results demonstrate that the BRFSS methodology introduces substantial uncertainty into reproductive health measures, which could bias population-based estimates. These findings emphasize the importance of implementing validated sex and gender questions in health surveillance surveys. See video abstract at,

    View details for DOI 10.1097/EDE.0000000000001046

    View details for PubMedID 31162292

  • Family building and pregnancy experiences of cisgender sexual minority women. AJOG global reports Tordoff, D. M., Moseson, H., Ragosta, S., Hastings, J., Flentje, A., Capriotti, M. R., Lubensky, M. E., Lunn, M. R., Obedin-Maliver, J. 2024; 4 (1): 100298


    Although 10% to 20% of cisgender women aged 18 to 40 years have a sexual minority identity (eg, bisexual, lesbian, and queer), there is limited research on the family building and pregnancy experiences of sexual minority cisgender women. Improving our understanding of the family building and pregnancy experiences of cisgender sexual minority women is critical for improving the perinatal health of this population.This study aimed to compare the mode of family building, past pregnancy experiences, and future pregnancy intentions among cisgender sexual minority women by sexual orientation.This is an observational study which was conducted using cross-sectional data collected in 2019 from a national sample of 1369 cisgender sexual minority women aged 18 to 45 years.Most participants (n=794, 58%) endorsed multiple sexual orientations, most commonly queer (n=641, 47%), lesbian (n=640, 47%), and/or bisexual (n=583, 43%). There were 243 (18%) cisgender sexual minority women who were parents. Pregnancy was used by 74% (181/243) of women to build their families. Among participants who used pregnancy, 60% (108/181) became pregnant through sexual activity with another parent of the child, whereas 27% (64/243) of women used donor sperm. An additional 10% (n=24) became parents through second-parent adoption, 10% (n=25) through adoption, and 14% (n=35) through step-parenting. Bisexual women more often used sexual activity to become parents (61/100, 61%) compared with queer (40/89, 45%) and lesbian women (40/130, 31%). In contrast, lesbian (50/130, 39%) and queer (25/89, 27%) women more often used donor sperm to become parents compared with bisexual women (11/100, 11%). Among the 266 (19%) cisgender sexual minority women who had ever been pregnant, there were 545 pregnancies (mean, 2.05 pregnancies per woman). Among those pregnancies, 59% (n=327) resulted in live birth, 23% (n=126) resulted in miscarriage, 15% (n=83) resulted in abortion, and 2% (n=9) resulted in ectopic pregnancy. A quarter of women had future pregnancy intentions, with no differences by sexual orientation. Overall, few participants (16%) reported that all of their healthcare providers were aware of their sexual orientation.Cisgender sexual minority women primarily built their families through pregnancy and a quarter have future pregnancy desires. In addition, there were important differences in family building methods used by sexual orientation. Providers should be aware of the pregnancy and family-building patterns, plans, and needs of cisgender sexual minority women.

    View details for DOI 10.1016/j.xagr.2023.100298

    View details for PubMedID 38269079

    View details for PubMedCentralID PMC10806344

  • Lessons learned from community engagement regarding phylodynamic research with molecular HIV surveillance data JOURNAL OF THE INTERNATIONAL AIDS SOCIETY Tordoff, D. M., Minalga, B., Trejo, A., Shook, A., Kerani, R. P., Herbeck, J. T. 2023; 26: e26111


    The widespread implementation of molecular HIV surveillance (MHS) has resulted in an increased discussion about the ethical, human rights and public health implications of MHS. We narrate our process of pausing our research that uses data collected through MHS in response to these growing concerns and summarize the key lessons we learned through conversations with community members.The original study aimed to describe HIV transmission patterns by age and race/ethnicity among men who have sex with men in King County, Washington, by applying probabilistic phylodynamic modelling methods to HIV-1 pol gene sequences collected through MHS. In September 2020, we paused the publication of this research to conduct community engagement: we held two public-facing online presentations, met with a national community coalition that included representatives of networks of people living with HIV, and invited two members of this coalition to provide feedback on our manuscript. During each of these meetings, we shared a brief presentation of our methods and findings and explicitly solicited feedback on the perceived public health benefit and potential harm of our analyses and results.Some community concerns about MHS in public health practice also apply to research using MHS data, namely those related to informed consent, inference of transmission directionality and criminalization. Other critiques were specific to our research study and included feedback about the use of phylogenetic analyses to study assortativity by race/ethnicity and the importance of considering the broader context of stigma and structural racism. We ultimately decided the potential harms of publishing our study-perpetuating racialized stigma about men who have sex with men and eroding the trust between phylogenetics researchers and communities of people living with HIV-outweighed the potential benefits.HIV phylogenetics research using data collected through MHS data is a powerful scientific technology with the potential to benefit and harm communities of people living with HIV. Addressing criminalization and including people living with HIV in decision-making processes have the potential to meaningfully address community concerns and strengthen the ethical justification for using MHS data in both research and public health practice. We close with specific opportunities for action and advocacy by researchers.

    View details for DOI 10.1002/jia2.26111

    View details for Web of Science ID 001022572700001

    View details for PubMedID 37408448

    View details for PubMedCentralID PMC10323319

  • Randomized-controlled trials are methodologically inappropriate in adolescent transgender healthcare INTERNATIONAL JOURNAL OF TRANSGENDER HEALTH Ashley, F., Tordoff, D. M., Olson-Kennedy, J., Restar, A. J. 2023
  • Gender and Sexual Health-Related Knowledge Gaps and Educational Needs of Parents of Transgender and Non-Binary Youth. Archives of sexual behavior Kantor, L. Z., Tordoff, D. M., Haley, S. G., Crouch, J. M., Ahrens, K. R. 2023


    Parents can have a substantial impact on adolescent sexual decision-making, but few studies have explored the role of parents in providing sexual health information to transgender and non-binary (TNB) youth, a population that experiences significant sexual and mental health disparities and lower levels of perceived family support compared with other youth. This study aimed to elucidate existing knowledge gaps and content deemed important for a sexual health curriculum and educational materials for parents of TNB youth. We conducted 21 qualitative interviews with five parents of TNB youth, 11 TNB youth aged 18+, and five healthcare affiliates to identify parents' educational needs. We analyzed the data using theoretical thematic analysis and consensus coding. Parents self-reported multiple knowledge deficits regarding gender/sexual health for TNB individuals and were primarily concerned with long-term impacts of medical interventions. Youth goals for parents included greater understanding of gender/sexuality and sufficient knowledge to support youth through social transition to their affirmed gender identity. Content areas suggested for a future curriculum for parents of TNB youth included: basics of gender/sexuality, diverse narratives of TNB experiences/identities, gender dysphoria, non-medical gender-affirming interventions, medical gender-affirming interventions, and resources for peer support. Parents desired access to accurate information and wanted to feel equipped to facilitate affirming conversations with their child, something that could combat health disparities among TNB youth. An educational curriculum for parents has the potential to provide a trusted information source, expose parents to positive representations of TNB individuals, and help parents support their TNB child through decisions about potential gender-affirming interventions.

    View details for DOI 10.1007/s10508-023-02611-9

    View details for PubMedID 37233838

    View details for PubMedCentralID 10204642

  • Heterogeneity in HIV/Sexually Transmitted Infection Prevalence and Prevention Among the Partners of Transgender and Nonbinary People Tordoff, D. M., Minalga, B., Perry, N., Gross, B. M., Khosropour, C. N., Glick, S. A., Barbee, L. A., Duerr, A. LIPPINCOTT WILLIAMS & WILKINS. 2023: 280-287


    Transgender and nonbinary (TNB) people are diverse in their sexual orientation and partnerships. We describe the epidemiology of HIV/sexually transmitted infection (STI) prevalence and prevention utilization among the partners of TNB people in Washington State.We pooled data from five 2017 to 2021 cross-sectional HIV surveillance data sources to generate a large sample of TNB people and cisgender people who had a TNB partner in the past year. We described characteristics of recent partners of trans women, trans men, and nonbinary people and used Poisson regression to assess if having a TNB partner was associated with self-reported HIV/STIs prevalence, testing, and preexposure prophylaxis (PrEP) use.Our analysis included 360 trans women, 316 trans men, 963 nonbinary people, 2896 cis women, and 7540 cis men. Overall, 9% of sexual minority cis men, 13% of sexual minority cis women, and 36% of TNB participants reported having any TNB partners. There was significant heterogeneity in HIV/STI prevalence, testing, and PrEP use among the partners of TNB people by study participant gender and the gender of their sex partners. In regression models, having a TNB partner was associated with a higher likelihood of HIV/STI testing and PrEP use but was not associated with higher HIV prevalence.We observed significant heterogeneity in HIV/STI prevalence and preventative behaviors among the partners of TNB people. Given that TNB people are diverse in their sexual partnerships, there is a need to better understand individual-, dyad-, and structural-level factors that facilitate HIV/STI prevention across these diverse partnerships.

    View details for DOI 10.1097/OLQ.0000000000001796

    View details for Web of Science ID 000970797300006

    View details for PubMedID 36881439

  • Telemedicine Utilization Among Transgender and Gender-Diverse Adolescents Before and After the COVID-19 Pandemic. Telemedicine journal and e-health : the official journal of the American Telemedicine Association Lucas, R., Kahn, N., Bocek, K., Tordoff, D. M., Karrington, B., Richardson, L. P., Sequeira, G. M. 2023


    Introduction: Little is known about how expansion of telemedicine services during the COVID-19 pandemic has affected access to gender-affirming care for transgender and gender-diverse (TGD) youth. The purpose of this study was to explore differences in demographic characteristics and visit completion rates at a multidisciplinary gender clinic before and after telemedicine implementation in March 2020 and among telemedicine users and nonusers. Methods: Data were from electronic health records of Seattle Children's Gender Clinic (SCGC) patients seen between April 2019 and February 2021. We assessed differences in demographic characteristics and care utilization (i.e., encounter type and status) between April 2019 and February 2020 (pre-telemedicine) and April 2020 and February 2021 (post-telemedicine). Results: Of the 1,051 unique patients seen at SCGC during this time period, majority groups were as follows: 62% identified as transmasculine/male, 68% were non-Hispanic White, and 76% resided within 50 miles of the clinic. Statistically significant differences were observed in patient pronouns and insurance type when comparing the pre- and post-telemedicine periods (p < 0.01). Half (52%) of post-telemedicine period encounters were conducted through telemedicine, and telemedicine encounters were significantly more likely to be completed (72% vs. 50%) and less likely to be canceled (21% vs. 46%) compared with in-person encounters. Conclusions: Telemedicine services facilitated continued access to gender-affirming care services for TGD youth during the COVID-19 pandemic. Although the introduction of telemedicine did not exacerbate demographic disparities in access to this care, further research and interventions are warranted to address the ongoing disparities in access to gender-affirming care for youth of color and rural youth.

    View details for DOI 10.1089/tmj.2022.0382

    View details for PubMedID 36791325

  • Trans Youth Talk Back: A Foucauldian Discourse Analysis of Transgender Minors' Accounts of Healthcare Access QUALITATIVE HEALTH RESEARCH Shook, A. G., Tordoff, D. M., Clark, A., Hardwick, R., St. Pierre Nelson, W., Kantrowitz-Gordon, I. 2022; 32 (11): 1672-1689


    Contemporary transgender youth in the U.S. today face increasing stigmatization as extraordinary legislative attacks intensify discrimination and exclusion of these young people in healthcare, recreation, and school life. These attacks reflect broader political, religious, and cultural ideologies embedded in systems of power that regulate the provision of healthcare for American transgender youth. We apply Foucauldian discourse analysis and a theory-driven conceptual framework for structural analysis of transgender health inequities-Intersectionality Research for Transgender Health Justice-to identify discourses youth encounter within healthcare practice. We analyzed data from interviews conducted in Western Washington State with youth ages 13-17 (n =11) and asked how transgender subjectivity was constructed in their accounts and in what ways youth made use of the discursive resources available to them when navigating systems of care. Three sets of discourses-discourses of normativity, discourses of temporality, and discourse of access-characterized participants' narratives. We discuss how participants negotiated discursively situated systems of power in order to ensure their safety and access to care.

    View details for DOI 10.1177/10497323221114801

    View details for Web of Science ID 000823629400001

    View details for PubMedID 35818038

  • Trans-inclusive Sexual Health Questionnaire to Improve HIV/STI Care for Transgender Patients: Anatomic-site Specific STI Prevalence & Screening Rates. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America Tordoff, D. M., Dombrowski, J. C., Ramchandani, M. S., Barbee, L. A. 2022


    In 2018, the municipal Sexual Health Clinic in Seattle implemented trans-inclusive questions about sexual behavior, anatomy, gender-affirming surgeries, and STI symptoms in the clinic's computer-assisted self-interview (CASI) to improve care for transgender and non-binary (TNB) patients.We calculated test positivity and the proportion of TNB patient visits that received testing for HIV, syphilis, pharyngeal, rectal and urogenital gonorrhea (GC) and chlamydia (CT) before (5/2016-12/2018) and after (12/2018-2/2020) implementation of new CASI questions. We then calculated the proportion of asymptomatic patients who received anatomic-site specific screening based on reported exposures.There were 434 TNB patients with 489 and 337 clinic visits during the two periods, respectively. Non-binary patients assigned male at birth (AMAB) had the highest prevalence of GC (10% pharyngeal, 14% rectal, 12% urogenital). Transgender women, transgender men, and non-binary people AMAB had a high prevalence of rectal CT (10%, 9%, and 13%, respectively) and syphilis (9%, 5%, and 8%). Asymptomatic transgender women, transgender men and non-binary patients AMAB who reported exposures were more likely to receive extragenital GC/CT screening compared to non-binary patients assigned female at birth. After implementing trans-inclusive medical history questions, there was a 33% increase in the number of annual TNB patient visits, but no statistically significant increase HIV/STI testing among TNB patients.TNB people at our clinic had a high prevalence of extragenital STIs and syphilis. Implementation of trans-inclusive medical history questions at a clinic that serves cisgender and transgender patients was feasible and important for improving the quality of affirming and inclusive sexual healthcare.

    View details for DOI 10.1093/cid/ciac370

    View details for PubMedID 35594554

  • Factors Associated with Time to Receiving Gender-Affirming Hormones and Puberty Blockers at a Pediatric Clinic Serving Transgender and Nonbinary Youth TRANSGENDER HEALTH Tordoff, D. M., Sequeira, G. M., Shook, A. G., Williams, F., Hayden, L., Kasenic, A., Inwards-Breland, D., Ahrens, K. 2022
  • Geographic Variation in HIV Testing Among Transgender and Nonbinary Adults in the United States. Journal of acquired immune deficiency syndromes (1999) Tordoff, D. M., Zangeneh, S., Khosropour, C. M., Glick, S. N., McClelland, R. S., Dimitrov, D., Reisner, S., Duerr, A. 2022; 89 (5): 489-497


    Transgender and nonbinary (TNB) populations are disproportionately affected by HIV and few local health departments or HIV surveillance systems collect/report data on TNB identities. Our objective was to estimate the prevalence of HIV testing among TNB adults by US county and state, with a focus on the Ending the HIV Epidemic (EHE) geographies.We applied a Bayesian hierarchical spatial small area estimation model to data from the 2015 US Transgender Survey, a large national cross-sectional Internet-based survey. We estimated the county- and state-level proportion of TNB adults who ever tested or tested for HIV in the last year by gender identity, race/ethnicity, and age.Our analysis included 26,100 TNB participants with valid zip codes who resided in 1688 counties (54% of all 3141 counties that cover 92% of the US population). The median county-level proportion of TNB adults who ever tested for HIV was 44% (range 10%-80%) and who tested in the last year was 17% (range 4%-44%). Within most counties, testing was highest among transgender women, black respondents, and people aged ≥25 years. HIV testing was lowest among nonbinary people and young adults aged <25 years. The proportion of TNB adults who tested within the last year was very low in most EHE counties and in all 7 rural states.HIV testing among TNB adults is likely below national recommendations in the majority of EHE geographies. Geographic variation in HIV testing patterns among TNB adults indicates that testing strategies need to be tailored to local settings.

    View details for DOI 10.1097/QAI.0000000000002909

    View details for PubMedID 35001041

    View details for PubMedCentralID PMC9058176

  • Erasure and Health Equity Implications of Using Binary Male/Female Categories in Sexual Health Research and Human Immunodeficiency Virus/Sexually Transmitted Infection Surveillance: Recommendations for Transgender-Inclusive Data Collection and Reporting. Sexually transmitted diseases Tordoff, D. M., Minalga, B., Gross, B. B., Martin, A., Caracciolo, B., Barbee, L. A., Balkus, J. E., Khosropour, C. M. 2022; 49 (2): e45-e49

    View details for DOI 10.1097/OLQ.0000000000001533

    View details for PubMedID 34407018

    View details for PubMedCentralID PMC8755589

  • HIV transmission patterns among transgender women, their cisgender male partners, and cisgender MSM in Lima, Peru: A molecular epidemiologic and phylodynamic analysis LANCET REGIONAL HEALTH-AMERICAS Long, J. E., Tordoff, D. M., Reisner, S. L., Dasgupta, S., Mayer, K. H., Mullins, J., Lama, J. R., Herbeck, J. T., Duerr, A. 2022; 6


    Transgender women (TW) in Peru are disproportionately affected by HIV. The role that cisgender men who have sex with TW (MSTW) and their sexual networks play in TW's risk of acquiring HIV is not well understood. We used HIV sequences from TW, MSTW, and cisgender men who have sex with men (MSM) to examine transmission dynamics between these groups.We used HIV-1 pol sequences and epidemiologic data collected through three Lima-based studies from 2013 to 2018 (n = 139 TW, n = 25 MSTW, n = 303 MSM). We identified molecular clusters based on pairwise genetic distance and used structured coalescent phylodynamic modeling to estimate transmission patterns between groups.Among 200 participants (43%) found in 62 clusters, the probability of clustering did not differ by group. Both MSM and TW were more likely to cluster with members of their own group than would be expected based on random mixing. Phylodynamic modeling estimated that there was frequent transmission from MSTW to TW (67·9% of transmission from MSTW; 95%CI = 52·8-83·2%) and from TW to MSTW (76·5% of transmissions from TW; 95%CI = 65·5-90·3%). HIV transmission between MSM and TW was estimated to comprise a small proportion of overall transmissions (4·9% of transmissions from MSM, and 11·8% of transmissions from TW), as were transmissions between MSM and MSTW (7·2% of transmissions from MSM, and 32·0% of transmissions from MSTW).These results provide quantitative evidence that MSTW play an important role in TW's HIV vulnerability and that MSTW have an HIV transmission network that is largely distinct from MSM.

    View details for DOI 10.1016/j.lana.2021.100121

    View details for Web of Science ID 000904622900013

    View details for PubMedID 35178526

    View details for PubMedCentralID PMC8849555

  • Phylogenetic estimates of SARS-CoV-2 introductions into Washington State LANCET REGIONAL HEALTH-AMERICAS Tordoff, D. M., Greninger, A. L., Roychoudhury, P., Shrestha, L., Xie, H., Jerome, K. R., Breit, N., Huang, M., Famulare, M., Herbeck, J. T. 2021; 1: 100018


    The first confirmed case of SARS-CoV-2 in North America was identified in Washington state on January 21, 2020. We aimed to quantify the number and temporal trends of out-of-state introductions of SARS-CoV-2 into Washington.We conducted a molecular epidemiologic analysis of 11,422 publicly available whole genome SARS-CoV-2 sequences from GISAID sampled between December 2019 and September 2020. We used maximum parsimony ancestral state reconstruction methods on time-calibrated phylogenies to enumerate introductions/exports, their likely geographic source (US, non-US, and between eastern and western Washington), and estimated date of introduction. To incorporate phylogenetic uncertainty into our estimates, we conducted 5,000 replicate analyses by generating 25 random time-stratified samples of non-Washington reference sequences, 20 random polytomy resolutions, and 10 random resolutions of the reconstructed ancestral state.We estimated a minimum 287 introductions (range 244-320) into Washington and 204 exported lineages (range 188-227) of SARS-CoV-2 out of Washington. Introductions began in mid-January and peaked on March 29, 2020. Lineages with the Spike D614G variant accounted for the majority (88%) of introductions. Overall, 61% (range 55-65%) of introductions into Washington likely originated from a source elsewhere within the US, while the remaining 39% (range 35-45%) likely originated from outside of the US. Intra-state transmission accounted for 65% and 28% of introductions into eastern and western Washington, respectively.The SARS-CoV-2 epidemic in Washington was continually seeded by a large number of introductions. Our findings highlight the importance of genomic surveillance to monitor for emerging variants due to high levels of inter- and intra-state transmission of SARS-CoV-2.None.

    View details for DOI 10.1016/j.lana.2021.100018

    View details for Web of Science ID 000904617400009

    View details for PubMedID 35013735

    View details for PubMedCentralID PMC8733893

  • "Talk about Bodies": Recommendations for Using Transgender-Inclusive Language in Sex Education Curricula SEX ROLES Tordoff, D. M., Haley, S. G., Shook, A., Kantor, A., Crouch, J. M., Ahrens, K. 2021; 84 (3-4): 152-165
  • Sex Education for Transgender and Non-Binary Youth: Previous Experiences and Recommended Content. The journal of sexual medicine Haley, S. G., Tordoff, D. M., Kantor, A. Z., Crouch, J. M., Ahrens, K. R. 2019; 16 (11): 1834-1848


    Transgender and non-binary (TNB) youth face disparities in sexual health risks compared with cisgender peers. Comprehensive sex education programs have the potential to result in delayed sexual debut, increased condom and contraceptive use, and reduced sexual risk-taking; however, little research has explored the specific sex education needs of TNB youth.To use insights from TNB youth, parents of TNB youth, and healthcare affiliates to understand deficits in sex education experienced by TNB youth, and to elicit recommended content for a comprehensive and trans-inclusive sex education curriculum.We conducted 21 in-depth interviews with non-minor TNB youth (n = 11) and with parents (n = 5) and healthcare affiliates (n = 5) of TNB youth recruited from Seattle Children's Gender Clinic and local TNB community listerv readerships. Data was analyzed using theoretical thematic analysis.Participants described prior sex education experiences and content needs of TNB youth.Participants described 5 key sources where TNB youth received sexual health information: school curricula, medical practitioners, peers, romantic partners, and online media. Inapplicability of school curricula and variable interactions with medical practitioners led youth to favor the latter sources. 8 content areas were recommended as important in sex education for TNB youth: puberty-related gender dysphoria, non-medical gender-affirming interventions, medical gender-affirming interventions, consent and relationships, sex and desire, sexually transmitted infection prevention, fertility and contraception, and healthcare access.Dependence on potentially inaccurate sex education sources leaves TNB youth vulnerable to negative outcomes, including sexually transmitted infections, pregnancy, unsanitary/unsafe sex toy use, and shame about their body or sexual desires.Strengths included capturing perspectives of an underserved population using open-ended interview questions, which allowed topics of greatest importance to participants to arise organically. Limitations included a sample size of 21 participants, and racial and geographic homogeneity of youth and parent participants. Only 1 author identifies as TNB. One-on-one interview methods may have omitted participants who would otherwise have been willing to share their perspective in a more impersonal format.This study demonstrates that TNB youth have unique sex education needs that are not well covered in most sexual health curricula. Recommended content for this population includes standard sex education topics that require trans-inclusive framing (eg, contraception), topics specific to TNB youth (eg, gender-affirming medical interventions), and topics absent from standard curricula that warrant universal teaching (eg, information on consent as it relates to sex acts aside from penile-vaginal sex). Haley SG, Tordoff DM, Kantor AZ, et al. Sex Education for Transgender and Non-Binary Youth: Previous Experiences and Recommended Content. J Sex Med 2019;16:1834-1848.

    View details for DOI 10.1016/j.jsxm.2019.08.009

    View details for PubMedID 31585806

  • Increased Ascertainment of Transgender and Non-binary Patients Using a 2-Step Versus 1-Step Gender Identity Intake Question in an STD Clinic Setting. Sexually transmitted diseases Tordoff, D. M., Morgan, J., Dombrowski, J. C., Golden, M. R., Barbee, L. A. 2019; 46 (4): 254-259


    Transgender inclusive and gender affirmative healthcare includes asking patients about gender identity and sex assigned at birth through what is known as the "2-step" methodology. In May 2016, the sexually transmitted disease (STD) clinic in Seattle, WA switched from using a 1-step to a 2-step gender identity question. We aimed to determine if the updated questions increased ascertainment of transgender and gender nonconforming (TGNC) patients and used the improved gender identity data to describe the human immunodeficiency virus/STD risk profile of TGNC patients.We conducted a pre-post analysis comparing the proportion of patients that identified as TGNC during the year before and after implementation of the 2-step questions. Gender identity and medical history questions were ascertained using a computer-assisted self-interview. The 2-step question included 2 new gender response options: non-binary/genderqueer and write-in.Institution of the 2-step question resulted in a 4.8-fold increase in patients who were identified as TGNC: 36 (0.5%) of 6635 to 172 (2.4%) of 7025 patients (P < 0.001). After implementation, 89 patients identified as non-binary/genderqueer (51.7% of TGNC patients). The proportion of patients identified as transgender men and women increased from 0.2% to 0.5% (P = 0.002) and 0.4% to 0.6% (P = 0.096), respectively. Non-binary patients' human immunodeficiency virus/sexually transmitted infection risk profile was distinct from that of transgender and cisgender men who have sex with men, suggesting that distinguishing subpopulations within the TGNC population is important for risk stratification.Using a 2-step gender identity question and including non-binary/genderqueer options increased our clinic's ascertainment of TGNC patients and more accurately captured gender identity among STD clinic patients.

    View details for DOI 10.1097/OLQ.0000000000000952

    View details for PubMedID 30516726