Quantification of private information leakage from phenotype-genotype data: linking attacks.

Studies on genomic privacy have traditionally focused on identifying individuals using DNA variants. In contrast, molecular phenotype data, such as gene expression levels, are generally assumed to be free of such identifying information. Although there is no explicit genotypic information in phenotype data, adversaries can statistically link phenotypes to genotypes using publicly available genotype-phenotype correlations such as expression quantitative trait loci (eQTLs). This linking can be accurate when high-dimensional data (i.e., many expression levels) are used, and the resulting links can then reveal sensitive information (for example, the fact that an individual has cancer). Here we develop frameworks for quantifying the leakage of characterizing information from phenotype data sets. These frameworks can be used to estimate the leakage from large data sets before release. We also present a general three-step procedure for practically instantiating linking attacks and a specific attack using outlier gene expression levels that is simple yet accurate. Finally, we describe the effectiveness of this outlier attack under different scenarios.

On the Content of "Real-World" Sexual Fantasy: Results From an Analysis of 250,000+ Anonymous Text-Based Erotic Fantasies.

A recurring problem with the study of sexual fantasy is that of social desirability bias. Study participants may report fantasies that are consistent with general societal expectations of fantasy content, as opposed to themes characterized by their actual fantasies. The wide availability of erotic material on the Internet, however, facilitates the study of sexual fantasy narratives as they are anonymously expressed and viewed online. By extracting approximately 250,000 text-based erotic fantasies from a user-generated website, we sought to examine "real-world" sexual fantasies, determine the themes that were typical of these narratives, and explore the relationship between themes and story popularity (as assessed by story views per day). A principal components analysis identified 20 themes that commonly occurred across the massive corpus, and a path analysis revealed that these themes played a significant role in predicting the popularity of the sexual fantasy narratives. In particular, the empirically identified themes reflecting familial words (e.g., mother, father) and colloquial sexual words (e.g., cock, fuck) were predictive of story popularity. Other themes identified included those not obviously erotic, such as those consisting of words reflecting domesticity (e.g., towel, shower) and colors (e.g., brown, blue). By analyzing a sexual fantasy corpus of unprecedented size, this study offers unique insight into both the content of sexual fantasies and the popularity of that content.

Influence of anonymous HIV testing on national HIV surveillance in the Republic of Korea (2000 to 2015): a retrospective analysis.

BACKGROUND: Owing to the continuous increase in the number of new human immunodeficiency virus (HIV) infection in Korea, public health centers (PHCs) have performed anonymous tests since 1989. No study has examined the patterns of anonymous HIV testing performed at PHCs and the characteristics of HIV infection detected in those tests. We aimed to assess the influence of anonymous HIV testing on Korea's national HIV surveillance. METHODS: HIV screening test data from 253 PHCs over a 16-year period were classified into 13 groups based on reason for testing. For anonymous HIV test takers (Anonymous), the HIV positivity per 10,000 tests was calculated, as repetitions could not be distinguished. Those with suspected HIV infection voluntarily underwent HIV testing and revealed their identity (Suspected). HIV prevalence was calculated as the number of HIV-positive persons per 10,000 test takers. Analyses were performed using chi-square and Cochran-Armitage trend test with SAS 9.4. RESULTS: Approximately 400,000 HIV screening tests were performed at PHCs annually, which remained unchanged in the past 10 years. The proportion of anonymous testing increased from < 3.0% before 2014 to 4.8% in 2014 and 6.1% in 2015. While the number of HIV cases increased, the number of anonymous HIV-positive test results per 10,000 tests decreased from 68.8 in 2010 to 41.8 in 2015. The HIV prevalence among the suspected was approximately 20.0 per 10,000 test takers before 2014, which steeply increased to 71.6 in 2015. Those with suspected HIV were predominantly men, aged 20 years, foreigners, and metropolitan city dwellers in the last 6 years. The high prevalence of persons with suspected HIV resulted in a doubling of HIV prevalence at PHCs between 2014 and 2015. CONCLUSIONS: Anonymous and Suspected, which were driven by similar motives, impacted each other. Increase in HIV prevalence among the suspected led to a higher HIV prevalence among all test takers in PHCs and higher proportions of HIV infection nationwide, which could be attributed to the increase in the number of anonymous tests performed in PHCs. HIV positivity among the anonymous and HIV prevalence among the suspected are key indexes of the national HIV surveillance in Korea.

Feasibility of an internet-based HIV testing service: anonymous urine collection from men who have sex with men.

A large proportion of people who are HIV positive do not know their serostatus because facility-based provider-initiated HIV testing and counseling, and voluntary counseling and testing, have not been efficiently implemented in China. Therefore, a new HIV testing strategy must be developed to improve testing services so that more HIV infections can be detected earlier. In this study, we established an anonymous internet-aided urine-based HIV testing service for men who have sex with men (MSM) from 1 April 2016 to 20 January 2017. In total, 3092 urine sample collection packs were distributed by grassroots organizations to MSM; 1977 (69.3%) packs were mailed back to the laboratory; and 1911 (96.7%) eligible samples were tested for HIV antibody. The rate of HIV antibody positivity was 7.1% (135/1901), excluding 10 previously-identified HIV infections. Of those tested, 65.4% (1243/1901) participants obtained their results from our website, 94 (69.6%) of 135 newly-identified urine HIV antibody-positive participants were contacted by CDC staff, and 61.7% (58/94) reported undergoing blood HIV antibody confirmation testing after learning of their urine HIV antibody test results. Of those who were tested for venous HIV antibody, 84.5% (49/58) reported being confirmed HIV antibody positive. Thirty-six of the newly diagnosed participants were successfully referred to a hospital to receive antiretroviral therapy. The rate of confirmed HIV antibody positivity was estimated to be 72.8-89.2 times of that of routine HIV antibody testing. In conclusion, this approach offers an alternative efficient HIV testing strategy to identify HIV positive persons in vulnerable populations.

Transforming classroom questioning using emerging technology.

Classroom questioning is a common teaching and learning strategy in postgraduate nurse education. Technologies such as audience response systems (ARS) may offer advantage over traditional approaches to classroom questioning. However, despite being available since the 1960s, ARSs are still considered novel in many postgraduate nurse education classroom settings. This article aims to explicate the attitudes of postgraduate nursing students in an Irish academic teaching hospital towards classroom questioning (CQ) and the use of ARSs as an alternative to traditional CQ techniques. The results of this small-scale study demonstrate that ARSs have a role to play in CQ in the postgraduate setting, being regarded by students as beneficial to learning, psychological safety and classroom interaction.

Addiction: an underestimated problem in psoriasis health care.

BACKGROUND: Psoriasis is a disease of enormous socio-economic impact. Despite approval of numerous highly efficient and costly therapies, a minor proportion of severely affected patients actually receives sufficient treatment. OBJECTIVE: To investigate whether addictions are associated with psoriasis and to develop evidence-based recommendations for dermatologists in their daily clinical practice in order to improve medical assessment of psoriasis and patients' quality of life. PATIENTS AND METHODS: Psoriasis patients at the University Department of Dermatology were asked to fill out a paper-based self-reported anonymous questionnaire with 92 questions of validated screening tests for the six most common addictions in Germany (alcohol, nicotine, drugs and illegal drugs, gambling, food). Body weight and height as well as current Psoriasis Area and Severity Index (PASI) were documented as well. RESULTS: Between October 2015 and February 2016, 102 patients (65 males, 37 females; mean age 49.7 years (SD 13.4), range 18-83 years) participated in the study. Fifty-seven of the 102 patients showed addictive behaviour. Of these, 23.8% were high-risk drinkers, 41% regular smokers, 11% at risk of drug abuse, 4.1% at risk of food dependency and 19% compulsive gamblers. Compared with the general population, these results are significantly higher for alcohol abuse (P < 0.005), nicotine (P < 0.001) and gambling (P < 0.001). Body mass index was significantly higher in the study population (P < 0.001). CONCLUSION: Addictions and gambling are more prevalent in patients with psoriasis compared with the general population. Respective screening measures are recommended in daily practice for doctors treating psoriasis patients, and PeakPASI is suggested as a score to document patients' lifetime highest PASI. Parallel to new drug approvals and even more detailed insights into the pathomechanism of psoriasis, public health strategies and interdisciplinary approaches are essential for a general sustained psoriasis treatment.

Beyond Condoms: Risk Reduction Strategies Among Gay, Bisexual, and Other Men Who Have Sex With Men Receiving Rapid HIV Testing in Montreal, Canada.

Gay, bisexual, and other men who have sex with men (MSM) have adapted their sexual practices over the course of the HIV/AIDS epidemic based on available data and knowledge about HIV. This study sought to identify and compare patterns in condom use among gay, bisexual, and other MSM who were tested for HIV at a community-based testing site in Montreal, Canada. Results showed that while study participants use condoms to a certain extent with HIV-positive partners and partners of unknown HIV status, they also make use of various other strategies such as adjusting to a partner's presumed or known HIV status and viral load, avoiding certain types of partners, taking PEP, and getting tested for HIV. These findings suggest that MSM who use condoms less systematically are not necessarily taking fewer precautions but may instead be combining or replacing condom use with other approaches to risk reduction.

Can we use postal surveys with anonymous testing to monitor chlamydia prevalence in young women in England? Pilot study incorporating randomised controlled trial of recruitment methods.

OBJECTIVES: Chlamydia prevalence in the general population is a potential outcome measure for the evaluation of chlamydia control programmes. We carried out a pilot study to determine the feasibility of using a postal survey for population-based chlamydia prevalence monitoring. METHODS: Postal invitations were sent to a random sample of 2000 17-year-old to 18-year-old women registered with a general practitioner in two pilot areas in England. Recipients were randomised to receive either a self-sampling kit (n=1000), a self-sampling kit and offer of £5 voucher on return of sample (n=500) or a self-sampling kit on request (n=500). Participants returned a questionnaire and self-taken vulvovaginal swab sample for unlinked anonymous Chlamydia trachomatis testing. Non-responders were sent a reminder letter 3 weeks after initial invitation. We calculated the participation rate (number of samples returned/number of invitations sent) and cost per sample returned (including cost of consumables and postage) in each group. RESULTS: A total of 155/2000 (7.8%) samples were returned with consent for testing. Participation rates varied by invitation group: 7.8% in the group who were provided with a self-sampling kit, 14% in the group who were also offered a voucher and 1.0% in the group who were not sent a kit. The cost per sample received was lowest (£36) in the group who were offered both a kit and a voucher. CONCLUSIONS: The piloted survey methodology achieved low participation rates. This approach is not suitable for population-based monitoring of chlamydia prevalence among young women in England. STUDY REGISTRATION NUMBER: (UKCRN ID 10913).

Occult hepatitis B virus coinfection in HIV-positive African migrants to the UK: a point prevalence study.

OBJECTIVES: Occult (surface antigen-negative/DNA-positive) hepatitis B virus (HBV) infection is common in areas of the world where HBV is endemic. The main objectives of this study were to determine the prevalence of occult HBV infection in HIV-infected African migrants to the UK and to determine factors associated with occult coinfection. METHODS: This anonymized point-prevalence study identified Africans attending three HIV clinics, focussing on patients naïve to antiretroviral therapy (ART). Stored blood samples were tested for HBV DNA. Prevalence was calculated in the entire cohort, as well as in subpopulations. Risk factors for occult HBV coinfection were identified using logistic regression analysis. RESULTS: Among 335 HIV-positive African migrants, the prevalence of occult HBV coinfection was 4.5% [95% confidence interval (CI) 2.8-7.4%] overall, and 6.5% (95% CI 3.9-10.6%) and 0.8% (95% CI 0.2-4.6%) in ART-naïve and ART-experienced patients, respectively. Among ART-naïve anti-HBV core (anti-HBc)-positive patients, the prevalence was 16.4% (95% CI 8.3-25.6%). The strongest predictor of occult coinfection was anti-HBc positivity [odds ratio (OR) 7.4; 95% CI 2.0-27.6]. Median HBV DNA and ALT levels were 54 IU/mL [interquartile range (IQR) 33-513 IU/mL] and 22 U/L (IQR 13-27 U/L), respectively. CONCLUSIONS: Occult HBV coinfection remains under-diagnosed in African HIV-infected patients in the UK. Given the range of HBV DNA levels observed, further studies are warranted to determine its clinical significance and to guide screening strategies and ART selection in these patients.

Policy recommendations for addressing privacy challenges associated with cell-based research and interventions.

BACKGROUND: The increased use of human biological material for cell-based research and clinical interventions poses risks to the privacy of patients and donors, including the possibility of re-identification of individuals from anonymized cell lines and associated genetic data. These risks will increase as technologies and databases used for re-identification become affordable and more sophisticated. Policies that require ongoing linkage of cell lines to donors' clinical information for research and regulatory purposes, and existing practices that limit research participants' ability to control what is done with their genetic data, amplify the privacy concerns. DISCUSSION: To date, the privacy issues associated with cell-based research and interventions have not received much attention in the academic and policymaking contexts. This paper, arising out of a multi-disciplinary workshop, aims to rectify this by outlining the issues, proposing novel governance strategies and policy recommendations, and identifying areas where further evidence is required to make sound policy decisions. The authors of this paper take the position that existing rules and norms can be reasonably extended to address privacy risks in this context without compromising emerging developments in the research environment, and that exceptions from such rules should be justified using a case-by-case approach. In developing new policies, the broader framework of regulations governing cell-based research and related areas must be taken into account, as well as the views of impacted groups, including scientists, research participants and the general public. SUMMARY: This paper outlines deliberations at a policy development workshop focusing on privacy challenges associated with cell-based research and interventions. The paper provides an overview of these challenges, followed by a discussion of key themes and recommendations that emerged from discussions at the workshop. The paper concludes that privacy risks associated with cell-based research and interventions should be addressed through evidence-based policy reforms that account for both well-established legal and ethical norms and current knowledge about actual or anticipated harms. The authors also call for research studies that identify and address gaps in understanding of privacy risks.

Overview and Methodology of the National HIV Behavioral Surveillance Among Transgender Women - Seven Urban Areas, United States, 2019-2020.

Transgender women, especially transgender women of color, are disproportionately affected by HIV. However, no surveillance system collects data on HIV risk factors among this population. To address this gap, CDC developed a surveillance system entitled National HIV Behavioral Surveillance Among Transgender Women (NHBS-Trans) to assess behavioral and contextual data through systematic biobehavioral surveillance to monitor behavioral risk factors, prevention usage, and HIV prevalence among transgender women. NHBS-Trans used respondent-driven sampling in seven urban areas in the United States. Trained interviewers used a standardized, anonymous questionnaire to collect information on HIV-related behavioral risk factors, HIV testing, and use of prevention services. Each of the seven participating project areas recruited approximately 200 eligible transgender women and offered anonymous HIV testing. Overall, in the seven project areas, 1,757 participants completed the eligibility screener for NHBS-Trans during 2019-2020; of these, 6.6% were seeds (i.e., a limited number of initial participants who were chosen by referrals from persons and community-based organizations who knew or were part of the local population of transgender women). A total of 1,637 (93.2%) participants were eligible, consented, and completed the interview. Of these, 1,624 (99.2%) agreed to HIV testing. Of the total 1,637 participants, 29 participants did not report identity of woman or transgender woman, resulting in a final sample of 1,608 transgender women. NHBS-Trans project area staff members (n = 14) reported that the survey was timely and addressed a critical need for HIV surveillance in a population that is often overlooked. The MMWR supplement includes this overview report on NHBS-Trans, which describes the methods (history, participant eligibility criteria, questionnaire, data collection, and HIV testing) as well as evaluation of project implementation and the performance of the questionnaire content, specifically the acceptability for transgender women. The other NHBS-Trans reports in the supplement include information on pre-exposure prophylaxis use, psychosocial syndemic conditions and condomless anal intercourse, nonprescription hormone use, homelessness, discrimination and the association between employment discrimination and health care access and use, and social support and the association between certain types of violence and harassment (gender-based verbal and physical abuse or harassment, physical intimate partner abuse or harassment, and sexual violence) and suicidal ideation. NHBS-Trans provides important data related to the goals of the Ending the HIV Epidemic in the U.S. initiative. Findings from NHBS-Trans can help guide community leaders, clinicians, and public health officials in improving access to and use of HIV prevention and treatment services by transgender women.

HIV risk profiles differed by gender and experience of men who had sex with men among attendees of anonymous voluntary counseling and testing in Taiwan.

Free voluntary counseling and testing (VCT) has been available in Taiwan as a part of HIV surveillance and prevention program since 1999, but related data were seldom reported. We aimed to examine characteristics of individuals who attended anonymous client-initiated VCT service and factors associated with HIV infection. The study population consisted of clients at two large VCT sites located in northern and southern Taiwan in 2004- 2008. Information on socio-demographic factors and potential risk behaviors was obtained by a questionnaire. Of 5671 clients, 65.1% were younger than 30 years; 42.0%, 41.2%, and 16.8% were men who ever had sex with men (MSM), non-MSM males, and women with HIV seropositivity of 8.0%, 1.2%, and 1.5%, respectively. The proportion of clients who confirmed having a prior HIV test was 66.5% in MSM, followed by 43% in non-MSM, and 30.2% in women. Correlates of HIV seropositivity differed between genders: ever engaging in commercial sex, being married or less educated were associated with increased risks among women but not for men. Different independent predictors were revealed among three groups of clients by multivariable analyses: illicit drug use, anal sex behavior, sexual partner(s) with HIV, and one-night stand in MSM; injection drug use and history of sexually transmitted infections in non-MSM; and injection drug use, sexual partner(s) with HIV and trading sex in women. Of all three groups, illicit drug or injection drug use was associated with the highest risks among all independent predictors. In this population of VCT clients in Taiwan, risk profiles of HIV infection differed according to gender and MSM experience, and different prevention strategies are needed to target different risk groups. In women, risk factors related to low social demographic and relationship power deserves attention in planning future prevention efforts.

Attitudes of UK psychiatrists to the diagnosis of MCI in clinical practice.

BACKGROUND: Mild cognitive impairment (MCI) may represent a transitional stage between normal functioning and dementia. Following the initial criteria developed by Petersen et al. in 1999, which focused on memory deficit in the context of otherwise normal cognition and general functioning, the concept has evolved with the introduction of subtypes of MCI and improved understanding of etiology. Our aim was to investigate current practice as well as familiarity with and attitudes toward the concept of MCI amongst UK old age psychiatrists. METHOD: We sent an anonymized postal survey to all clinicians on the Royal College of Psychiatrists Old Age Psychiatry register. Questions covered attitudes toward the concept of MCI in addition to diagnostic criteria and assessment tools used. RESULTS: The response rate was 39% (453 of 1,154 questionnaires returned completed). The majority of respondents were consultants (83%) and 91% diagnosed MCI. Only 4.4% of the respondents thought that the concept of MCI was not useful and 79% of them required a memory complaint from either the patient or an informant for a diagnosis, but the majority did not have a specific cut-off on cognitive testing. Eighty-two percent reported that they required no or minimal impairment in activities of daily living for a diagnosis of MCI. The two most frequently used tools for assessment were the Mini-Mental State Examination and the Addenbrooke's Cognitive Examination-Revised. CONCLUSIONS: Our survey shows that in the United Kingdom, the term MCI has become part of everyday clinical practice in psychiatry, suggesting that clinicians find it a useful term to conceptualize the transitional stage between normal aging and dementia. However, there is variability in diagnostic practice.

Anonymization of electronic medical records for validating genome-wide association studies.

Genome-wide association studies (GWAS) facilitate the discovery of genotype-phenotype relations from population-based sequence databases, which is an integral facet of personalized medicine. The increasing adoption of electronic medical records allows large amounts of patients' standardized clinical features to be combined with the genomic sequences of these patients and shared to support validation of GWAS findings and to enable novel discoveries. However, disseminating these data "as is" may lead to patient reidentification when genomic sequences are linked to resources that contain the corresponding patients' identity information based on standardized clinical features. This work proposes an approach that provably prevents this type of data linkage and furnishes a result that helps support GWAS. Our approach automatically extracts potentially linkable clinical features and modifies them in a way that they can no longer be used to link a genomic sequence to a small number of patients, while preserving the associations between genomic sequences and specific sets of clinical features corresponding to GWAS-related diseases. Extensive experiments with real patient data derived from the Vanderbilt's University Medical Center verify that our approach generates data that eliminate the threat of individual reidentification, while supporting GWAS validation and clinical case analysis tasks.

'Once the stuff's left my body, it's not me': service users' views on unlinked anonymous testing of blood for HIV.

This paper reports on the qualitative component of a mixed-methods study on unlinked anonymous testing for HIV in genitourinary medicine (GUM) clinics in two English cities. Unlinked anonymous testing is a system of monitoring population prevalence by testing residual blood samples taken for diagnostic purposes after they have been unlinked and anonymised from their source. Little is known about how individuals feel about their blood being tested in this way without their explicit consent, nor is it clear whether the process of unlinking blood affects how people feel about the use of their bodily material for public health surveillance purposes. We report participants' views on these issues, drawing on in-depth interviews with 20 GUM clinic users. The majority thought it preferable for blood samples to be used for population surveillance rather than being discarded. For most, blood and bodily tissue were not seen to represent personal identity even though participants understood that information about them could be gleaned from their analysis. The provision of information, rather than a strict consent process, was advocated as many felt that transactions between health professionals and patients should be as transparent as possible.

Foreign students' experience during a time of war.

BACKGROUND: Due to the war in Gaza in 2009, Ben-Gurion University's Medical School for International Health with a student body of 165 international multicultural students canceled a week of classes. Third-year students continued clerkships voluntarily and fourth-year students returned to Israel before departing for electives in a developing country. A debriefing session was held for the entire school. OBJECTIVES: To assess the academic and psychological effects of political conflict on students. METHODS: We asked all students to fill out an anonymous Google electronic survey describing their experience during the war and evaluating the debriefing. A team of students and administrators reviewed the responses. RESULTS: Sixty-six students (40% of the school) responded (first year 26%, second year 39%, third year 24%, fourth year 8%, taking time off 3%, age 23-40 years old). Eighty-three percent were in Israel for some portion of the war and 34% attended the debriefing. Factors that influenced individuals' decision to return/stay in the war zone were primarily of an academic and financial nature. Other factors included family pressure, information from peers and information from the administration. Many reported psychological difficulties during the war rather than physical danger, describing it as "draining" and that it was difficult to concentrate while studying. As foreigners, many felt their role was undefined. Although there is wide variation in the war's effect on daily activities and emotional well-being during that time, the majority (73%) reported minimal residual effects. CONCLUSIONS: This study lends insight to the way students cope during conflict and highlights academic issues during a war. Open and frequent communication and emphasis on the school as a community were most important to students.

Under-reporting of alcohol and substance use versus other psychiatric symptoms in individuals living with HIV.

Substance use is known to negatively impact outcomes in patients living with HIV by decreasing adherence to and effectiveness of antiretroviral therapies. Alcohol and other drug abuse and dependence are widespread among HIV-positive individuals, though reported rates vary greatly by study, suggesting the possibility of under-reporting. The extent to which patients minimize symptoms and the factors that influence reporting remain to be determined. The present study sought to gauge the degree to which substance use is under-reported in a primary care HIV clinic by evaluating the influence of anonymity versus confidentiality of self-report on endorsement rates. Patients (n = 55) currently receiving medical treatment completed a confidential questionnaire assessing the presence of alcohol abuse, other drug misuse, and Generalized Anxiety Disorder (GAD). Another group of 55 patients completed a comparable survey, but did so anonymously. The two groups were similar in terms of demographic characteristics, but self-report of substance use differed depending on how symptoms were assessed, with anonymous questionnaires yielding significantly (p<0.05) higher rates, compared to confidential surveys. Under-reporting appeared specific to alcohol and substance use, with no statistically significant differences between anonymous and confidential surveys in the proportion of patients endorsing symptoms of GAD. The fact that the screener specifically designed to identify patients in need of further evaluation produced lower rates of reported alcohol and drug use suggests that more work is needed to identify appropriate tools for accurately assessing substance use in HIV-positive patients so that adequate referrals and services can be offered to those in need.

How anonymous is 'anonymous'? Some suggestions towards a coherent universal coding system for genetic samples.

So-called 'anonymous' tissue samples are widely used in research. Because they lack externally identifying information, they are viewed as useful in reconciling conflicts between the control, privacy and confidentiality interests of those from whom the samples originated and the public (or commercial) interest in carrying out research, as reflected in 'consent or anonymise' policies. High level guidance documents suggest that withdrawal of consent and samples and the provision of feedback are impossible in the case of anonymous samples. In view of recent developments in science and consumer-driven genomics the authors argue that such statements are misleading and only muddle complex ethical questions about possible entitlements to control over samples. The authors therefore propose that terms such as 'anonymised', 'anonymous' or 'non-identifiable' be removed entirely from documents describing research samples, especially from those aimed at the public. This is necessary as a matter of conceptual clarity and because failure to do so may jeopardise public trust in the governance of large scale databases. As there is wide variation in the taxonomy for tissue samples and no uniform national or international standards, the authors propose that a numeral-based universal coding system be implemented that focuses on specifying incremental levels of identifiability, rather than use terms that imply that the reidentification of research samples and associated actions are categorically impossible.