By Professor Kevan Wylie on the 1 August 2009.
ABSTRACT
Gender dysphoria• An anxiety, uncertainty or persistently uncomfortable feelings experienced by an individual about their assigned gender which is in conflict with their internal gender identity.
• Gender dysphoria is a medical condition in which a person has been assigned one gender at birth but identifies as another gender, or does not conform to the gender role society ascribes to them. Gender dysphoria is not related to sexual orientation. Gender dysphoria has replaced gender identity disorder as the word disorder is seen as stigmatising.
• A person with gender dysphoria can experience anxiety, uncertainty or persistently uncomfortable feelings about their gender assigned at birth. This dysphoria may lead to a fear of expressing their feelings or of rejection and in some cases deep anxiety or chronic depression. It is effectively treated using methods such as counselling, hormone replacement therapy, surgery or simply social transition.
• Distress resulting from a difference between a person’s gender and the person’s assigned sex, associated gender role, and/or primary and secondary sex characteristics.
is a rare clinical condition that may present to the physician, requiring recognition and appropriate support. Clinical pathways have now been clarified and there are a number of interventions that can be affirmative and supportive for patients who may face considerable social and domestic challenges to their situation.
Atypical gender• However gender is far more complicated. It is the complex interrelationship between an individual’s sex (gender biology), one’s internal sense of self as male, female, both or neither (gender identity) as well as one’s outward presentations and behaviours (gender expression) related to that perception, including their gender role. Together, the intersection of these three dimensions produces one’s authentic sense of gender, both in how people experience their own gender as well as how others perceive it.
• Gender is expressed in terms of masculinity and femininity. It is largely culturally determined and is assigned at birth based on the sex of the individual. It affects how people perceive themselves and how they expect others to behave.
• Socially and culturally constructed roles, behaviours, expressions and identities of girls, women, boys, men, and trans people.
development can result in the experience of one’s self as a manA human being who self-identifies as a man, based on elements of importance to the individual, such as gender roles, behaviour, expression, identity, and/or physiology. or a womanA human being who self-identifies as a woman, based on elements of importance to the individual, such as gender roles, behaviour, expression, identity, and/or physiology. (gender identity• One’s innermost concept of self as male or female or both or neither – how individuals perceive themselves and what they call themselves. One’s gender identity can be the same or different than the sex assigned at birth. Individuals are conscious of this between the ages 18 months and 3 years. Most people develop a gender identity that matches their biological sex. For some, however, their gender identity is different from their biological or assigned sex. Some of these individuals choose to socially, hormonally and/or surgically change their sex to more fully match their gender identity.
• The gender to which one feels one belongs.
• Internal and psychological sense of oneself as a woman, a man, both, in between, or neither.
) that is incongruous with the body phenotype (physical sexTo what sex do the organs of the body match, i.e. male or female. Birth with ambiguous genitalia occurs in roughly 1:2000 live births (see Intersex Person). characteristics). This incongruence may result in gender dysphoria• An anxiety, uncertainty or persistently uncomfortable feelings experienced by an individual about their assigned gender which is in conflict with their internal gender identity.
• Gender dysphoria is a medical condition in which a person has been assigned one gender at birth but identifies as another gender, or does not conform to the gender role society ascribes to them. Gender dysphoria is not related to sexual orientation. Gender dysphoria has replaced gender identity disorder as the word disorder is seen as stigmatising.
• A person with gender dysphoria can experience anxiety, uncertainty or persistently uncomfortable feelings about their gender assigned at birth. This dysphoria may lead to a fear of expressing their feelings or of rejection and in some cases deep anxiety or chronic depression. It is effectively treated using methods such as counselling, hormone replacement therapy, surgery or simply social transition.
• Distress resulting from a difference between a person’s gender and the person’s assigned sex, associated gender role, and/or primary and secondary sex characteristics.
, which in its most persistent and profound state can cause individuals to seek assistance from their GP.
Gender dysphoria• An anxiety, uncertainty or persistently uncomfortable feelings experienced by an individual about their assigned gender which is in conflict with their internal gender identity.
• Gender dysphoria is a medical condition in which a person has been assigned one gender at birth but identifies as another gender, or does not conform to the gender role society ascribes to them. Gender dysphoria is not related to sexual orientation. Gender dysphoria has replaced gender identity disorder as the word disorder is seen as stigmatising.
• A person with gender dysphoria can experience anxiety, uncertainty or persistently uncomfortable feelings about their gender assigned at birth. This dysphoria may lead to a fear of expressing their feelings or of rejection and in some cases deep anxiety or chronic depression. It is effectively treated using methods such as counselling, hormone replacement therapy, surgery or simply social transition.
• Distress resulting from a difference between a person’s gender and the person’s assigned sex, associated gender role, and/or primary and secondary sex characteristics.
is a diagnosis that is essentially made by the patient. As such, the primary care clinician should aim to support patients through subsequent processes that are necessary if they are to secure relief from the dysphoria, including counselling, hormone therapy, surgical confirmation and other related changes.
Increasing awareness and tolerance of diversity in society has led to an increase in the number of patients seeking help with this relatively rare condition. The incidence is unknown, but figures of one trans• Trans is an umbrella term used to describe people whose lives appear to conflict with the gender norms of society. Whether this is in their clothing, in presenting themselves or undergoing hormone treatment and surgery. Being trans does not imply any specific sexual orientation.
• Trans is an umbrella term that describes a wide range of people whose gender and/or gender expression differ from their assigned sex and/or the societal and cultural expectations of their assigned sex; includes people who are androgyne, agender, bigender, butch, CAFAB, CAMAB, cross-dresser, drag king, drag queen, femme, FTM, gender creative, gender fluid, gender non-conforming, genderqueer, gender variant, MTF, pangender, questioning, trans, trans man, trans woman, transfeminine, transgender, transmasucline, transsexual, and two-spirit.
womanA human being who self-identifies as a woman, based on elements of importance to the individual, such as gender roles, behaviour, expression, identity, and/or physiology. per 12,000 of the population and one trans• Trans is an umbrella term used to describe people whose lives appear to conflict with the gender norms of society. Whether this is in their clothing, in presenting themselves or undergoing hormone treatment and surgery. Being trans does not imply any specific sexual orientation.
• Trans is an umbrella term that describes a wide range of people whose gender and/or gender expression differ from their assigned sex and/or the societal and cultural expectations of their assigned sex; includes people who are androgyne, agender, bigender, butch, CAFAB, CAMAB, cross-dresser, drag king, drag queen, femme, FTM, gender creative, gender fluid, gender non-conforming, genderqueer, gender variant, MTF, pangender, questioning, trans, trans man, trans woman, transfeminine, transgender, transmasucline, transsexual, and two-spirit.
manA human being who self-identifies as a man, based on elements of importance to the individual, such as gender roles, behaviour, expression, identity, and/or physiology. per 30,000 are likely to prove underestimates when techniques for calculating prevalence improve.
Initial steps in management
Guidelines for health organisations that commission treatment have been issued by the Parliamentary Forum of Transsexualism• This term is used to describe a person who has “transitioned”, or is in the process of “transitioning”, or intends to transition from male to female or female to male. For a transsexual person, the process of “transitioning”, may involve a variety of treatments including: hormone therapy, surgery and hair removal. People who have transitioned do not necessarily identify as trans any longer; they may identify as simply a man or a woman. Some transsexual people may not transition due to family or other social constraints.
• When people complete their transition, they may no longer regard themselves as part of the trans umbrella. They might consider having been transsexual to just be an aspect of their medical history which has now been resolved and so is no longer an issue in their life. In such cases, they simply describe themselves as men or as women and it is most disrespectful to insist on calling them trans, transgender or transsexual against their wishes.
and are available from the Gender Identity Research and Education Society. For care providers, the UK draft standards of care are available from the Royal College of Psychiatrists.
These documents provide important information about why care should be commissioned and the standards of care that should be provided by different staff members of gender• However gender is far more complicated. It is the complex interrelationship between an individual’s sex (gender biology), one’s internal sense of self as male, female, both or neither (gender identity) as well as one’s outward presentations and behaviours (gender expression) related to that perception, including their gender role. Together, the intersection of these three dimensions produces one’s authentic sense of gender, both in how people experience their own gender as well as how others perceive it.
• Gender is expressed in terms of masculinity and femininity. It is largely culturally determined and is assigned at birth based on the sex of the individual. It affects how people perceive themselves and how they expect others to behave.
• Socially and culturally constructed roles, behaviours, expressions and identities of girls, women, boys, men, and trans people.
teams or networks.
Patients who have made transition• The social, psychological, emotional and economic processes that a trans person undergoes to move from their assigned gender role into their chosen or acquired gender. The time this takes is variable and depends on the individual’s ability to embrace significant change in their life. If requiring genital surgery the individual will have to undergo a so called Real Life Test, i.e. living in their acquired gender role for a minimum of 1 year.
• Refers to the process during which trans people may change their gender expression and/or bodies to reflect their gender, including changes in physical appearance (hairstyle, clothing), behaviour (mannerisms, voice, gender roles), identification (name, pronoun, legal details), and/or medical interventions (hormone therapy, gender-affirming surgery).
can apply under the Gender Recognition Act (2004) for a gender recognition• The legal recognition of an individuals acquired gender as the opposite of the sex assigned at birth.
• Usually once a person has begun the process of transitioning, pronouns that are appropriate to the gender towards which he or she is transitioning should be used.
certificate, which entitles them to special protection of their privacy. This includes avoidance of unwarranted disclosure of information by healthcare professionals, with such disclosure amounting to a criminal offence.
The GP may act as the co-ordinator of care for a patient undergoing transition• The social, psychological, emotional and economic processes that a trans person undergoes to move from their assigned gender role into their chosen or acquired gender. The time this takes is variable and depends on the individual’s ability to embrace significant change in their life. If requiring genital surgery the individual will have to undergo a so called Real Life Test, i.e. living in their acquired gender role for a minimum of 1 year.
• Refers to the process during which trans people may change their gender expression and/or bodies to reflect their gender, including changes in physical appearance (hairstyle, clothing), behaviour (mannerisms, voice, gender roles), identification (name, pronoun, legal details), and/or medical interventions (hormone therapy, gender-affirming surgery).
, although they will more usually be the catalyst for referral to other specialist teams. The first referral should be to a local sector psychiatrist, for the exclusion of concurrent mental health problems (see box 1). The presence of any of these conditions does not necessarily preclude care for gender-related matters, which may coexist.
BOX 1: MENTAL HEALTH CONDITIONS TO CONSIDER
- Transvestism and fetishist conditions
- Anxiety states
- Social anxiety
- Depressive disorder
- Psychosis
- Alcohol dependence
- Schizophrenia
- Body dysmorphia
- Requests for cosmetic surgery
Concurrently, a patient can be referred to a gender identity• One’s innermost concept of self as male or female or both or neither – how individuals perceive themselves and what they call themselves. One’s gender identity can be the same or different than the sex assigned at birth. Individuals are conscious of this between the ages 18 months and 3 years. Most people develop a gender identity that matches their biological sex. For some, however, their gender identity is different from their biological or assigned sex. Some of these individuals choose to socially, hormonally and/or surgically change their sex to more fully match their gender identity.
• The gender to which one feels one belongs.
• Internal and psychological sense of oneself as a woman, a man, both, in between, or neither.
team, which may be based in one service or a wider network. A network of individuals (see box 2) may work independently but meet regularly to discuss the progress of patients under their care and to ensure supervision and governance of their work. The role of the psychiatrist and other gender• However gender is far more complicated. It is the complex interrelationship between an individual’s sex (gender biology), one’s internal sense of self as male, female, both or neither (gender identity) as well as one’s outward presentations and behaviours (gender expression) related to that perception, including their gender role. Together, the intersection of these three dimensions produces one’s authentic sense of gender, both in how people experience their own gender as well as how others perceive it.
• Gender is expressed in terms of masculinity and femininity. It is largely culturally determined and is assigned at birth based on the sex of the individual. It affects how people perceive themselves and how they expect others to behave.
• Socially and culturally constructed roles, behaviours, expressions and identities of girls, women, boys, men, and trans people.
specialists is fourfold. First is the differentiation of concurrent mental health problems. Second, diagnostic assessment confirming the diagnosis, as determined by the criteria of DSM-IV. These are a persisting conviction of belonging to the opposite biological sexBiological attributes and legal categories used to classify humans as male, female, intersex or other categories, primarily associated with physical and physiological features including chromosomes, genetic expression, hormone levels and function, and reproductive/sexual anatomy., duration at least two years, intensive psychological distress and the disorder not being a symptom of another disorder.
BOX 2: SPECIALISTS INVOLVED IN CARE
- Psychiatrist
- Psychologist
- Psychotherapist
- Specialist nurse practitioner
- EndocrinologistA medical doctor specially trained in the study of hormones and their actions and disorders in the body.
- GPSI
- Reproductive specialist (gamete storage)
- Electrolysis/laser hair specialist
- Breast surgeon
- Speech and language therapist
- ENT specialist (cricothyroid approximation)
- District nurse
Third is optimising the chance of a successful transformation and fourth is helping patients to gain self-insight, understand their options and develop coping strategies for changes to happen with appropriate medical and psychological support. After a minimum three months of living in the new gender role• This is the set of roles, activities, expectations and behaviors assigned to females and males by society. Our culture recognises two basic gender roles: Masculine (having the qualities attributed to males) and feminine (having the qualities attributed to females). People who step out of their socially assigned gender roles are sometimes referred to as transgender. Other cultures have three or more gender roles.
• Socially constructed and culturally behavioural norms, such as communication styles, careers and family roles, that are often expected of people based on their assigned sex.
or undergoing psychotherapy, the patient should be assessed for eligibility and readiness for hormone therapy, in line with international standards of care provided by the World Professional Association for Transgender Health
Eligibility is assessed by the practitioner. Readiness is an interactive exchange where the patient has made a decision based on sufficient knowledge and discussion of the benefits and consequences, as well as limitations of hormone therapy (see box 3). Full written informed consent should be obtained after detailed discussion.
BOX 3: QUESTIONS FOR THE PATIENT
- Do you have a clear mental picture of what you want life to be like after you start taking hormonesChemical substances that control and regulate the activity of certain cells or organs; see also: sex hormones.?
- How do you think you might feel if the results do not match your expectations?
- Are you hoping that taking hormone therapy will fix anything and if so, what?
- What part of your life might change after hormone therapy?
- What do you hope might change and what do you feel might change?
- Do you think your hopes are realistic and how can you tell if they are?
- How much do you know about hormone therapy?
- What more do you need to know for an informed decision?
- Who else in your life will be affected by your decision?
- How do you think they will feel about you taking hormonesChemical substances that control and regulate the activity of certain cells or organs; see also: sex hormones.?
- How will their reactions affect you?
- What do you think is a ‘wrong reason’ to take hormonesChemical substances that control and regulate the activity of certain cells or organs; see also: sex hormones.?
- What do you think are the ‘right reasons’?
Source: Transgender Health Program, Vancouver, Canada.
Prescribing hormone treatment
A full health assessment will have been undertaken and a recommendation for treatment provided by the specialist gender• However gender is far more complicated. It is the complex interrelationship between an individual’s sex (gender biology), one’s internal sense of self as male, female, both or neither (gender identity) as well as one’s outward presentations and behaviours (gender expression) related to that perception, including their gender role. Together, the intersection of these three dimensions produces one’s authentic sense of gender, both in how people experience their own gender as well as how others perceive it.
• Gender is expressed in terms of masculinity and femininity. It is largely culturally determined and is assigned at birth based on the sex of the individual. It affects how people perceive themselves and how they expect others to behave.
• Socially and culturally constructed roles, behaviours, expressions and identities of girls, women, boys, men, and trans people.
clinician, endorsed by the clinical team involved in assessment to that stage 1.
Health assessment, including physical examination, is important, particularly in the exclusion of intersex• This is a general term used for a variety of conditions in which a person is born with chromosomal, hormonal, and/or anatomical attributes that do not fit the “typical” definitions for female or male. Many intersex people are surgically “corrected” in infancy, and some grow up to feel like they have had an essential part of themselves taken away without their consent.
• A reproductive or sexual anatomy that does not closely resemble typical male or female reproductive or sexual anatomy, which may be related to genitalia, secondary sex characteristics, and/or chromosomal make-up; DSD replaced the outdated terms ‘hermaphrodite’; see also ‘disorders of sex development’; DSD is different from trans.
states. Examinations can be stressful for many patients who intensely dislike their genitals. There is a need to prepare the patient and provide necessary support, with either a chaperone or a limited examination, and this should be explained and documented.
Patients who are smokers are encouraged to give up before therapy begins. HormonesChemical substances that control and regulate the activity of certain cells or organs; see also: sex hormones. may be prescribed by the GP, gender• However gender is far more complicated. It is the complex interrelationship between an individual’s sex (gender biology), one’s internal sense of self as male, female, both or neither (gender identity) as well as one’s outward presentations and behaviours (gender expression) related to that perception, including their gender role. Together, the intersection of these three dimensions produces one’s authentic sense of gender, both in how people experience their own gender as well as how others perceive it.
• Gender is expressed in terms of masculinity and femininity. It is largely culturally determined and is assigned at birth based on the sex of the individual. It affects how people perceive themselves and how they expect others to behave.
• Socially and culturally constructed roles, behaviours, expressions and identities of girls, women, boys, men, and trans people.
specialist, endocrinologistA medical doctor specially trained in the study of hormones and their actions and disorders in the body., or in certain circumstances, nurse prescriber. It is not necessary for an endocrinologistA medical doctor specially trained in the study of hormones and their actions and disorders in the body. to initiate the prescription unless there is a concurrent hormone disorder.
The hormonesChemical substances that control and regulate the activity of certain cells or organs; see also: sex hormones. usually prescribed are listed in box 4. During hormone therapy, continuing physical assessment is necessary, with regular biochemical and heamatological measurements. Detailed guidance is available within standards of care documents and elsewhere 2 3.
BOX 4: OPTIONS FOR HORMONE TREATMENT
Trans women
- Estrogens, for example, estradiol
- Androgen antagonists, for example, spironolactone, finasteride, cyproterone
- Gonadotropin-releasing hormone (GnRH) agonists
- Topical hair removal creams, for example, eflornithine
Trans men
- Testosterone
- GnRH agonists
Transdermal estrogen is recommended for trans• Trans is an umbrella term used to describe people whose lives appear to conflict with the gender norms of society. Whether this is in their clothing, in presenting themselves or undergoing hormone treatment and surgery. Being trans does not imply any specific sexual orientation.
• Trans is an umbrella term that describes a wide range of people whose gender and/or gender expression differ from their assigned sex and/or the societal and cultural expectations of their assigned sex; includes people who are androgyne, agender, bigender, butch, CAFAB, CAMAB, cross-dresser, drag king, drag queen, femme, FTM, gender creative, gender fluid, gender non-conforming, genderqueer, gender variant, MTF, pangender, questioning, trans, trans man, trans woman, transfeminine, transgender, transmasucline, transsexual, and two-spirit.
women over 40 years of age 4. Minimum laboratory tests must be undertaken within three months of commencing treatment.
As patients prepare for surgical confirmation, it is necessary to withhold certain hormonal therapies because of the increased risk of thrombosis if estrogens are continued more than six weeks before surgery. Other factors, including high BMI and concurrent medical states, should be managed well in advance of the expected time for gender• However gender is far more complicated. It is the complex interrelationship between an individual’s sex (gender biology), one’s internal sense of self as male, female, both or neither (gender identity) as well as one’s outward presentations and behaviours (gender expression) related to that perception, including their gender role. Together, the intersection of these three dimensions produces one’s authentic sense of gender, both in how people experience their own gender as well as how others perceive it.
• Gender is expressed in terms of masculinity and femininity. It is largely culturally determined and is assigned at birth based on the sex of the individual. It affects how people perceive themselves and how they expect others to behave.
• Socially and culturally constructed roles, behaviours, expressions and identities of girls, women, boys, men, and trans people.
confirmation surgery.
Confirmation surgery
After a minimum of 12 months, during which the patient is supported through the real life experience, it is often the patient’s preference to proceed to genital confirmation surgery. To do so, an independent second affirmative recommendation is necessary, which may mean assessment at another clinic.
Once eligibility and readiness for surgery are confirmed, referral to a surgeon with specialist expertise should be undertaken without delay. This is usually done by the local gender• However gender is far more complicated. It is the complex interrelationship between an individual’s sex (gender biology), one’s internal sense of self as male, female, both or neither (gender identity) as well as one’s outward presentations and behaviours (gender expression) related to that perception, including their gender role. Together, the intersection of these three dimensions produces one’s authentic sense of gender, both in how people experience their own gender as well as how others perceive it.
• Gender is expressed in terms of masculinity and femininity. It is largely culturally determined and is assigned at birth based on the sex of the individual. It affects how people perceive themselves and how they expect others to behave.
• Socially and culturally constructed roles, behaviours, expressions and identities of girls, women, boys, men, and trans people.
team or the lead clinician in a network of patients. At least one of the two recommendations must be from a physician.
The involvement of a district nurse before and after surgery is invaluable, even if this is limited to liaison with the local district nursing team. Provision of postoperative care is necessary for psychological and physical health; sometimes, support continues beyond the time of surgical discharge.
In the past, many patients have abandoned services they found unhelpful during their transition• The social, psychological, emotional and economic processes that a trans person undergoes to move from their assigned gender role into their chosen or acquired gender. The time this takes is variable and depends on the individual’s ability to embrace significant change in their life. If requiring genital surgery the individual will have to undergo a so called Real Life Test, i.e. living in their acquired gender role for a minimum of 1 year.
• Refers to the process during which trans people may change their gender expression and/or bodies to reflect their gender, including changes in physical appearance (hairstyle, clothing), behaviour (mannerisms, voice, gender roles), identification (name, pronoun, legal details), and/or medical interventions (hormone therapy, gender-affirming surgery).
, owing to long periods between initial presentation and final surgery. Now, greater enlightenment among healthcare professionals and care commissioners will allow working relationships to develop between patients and care providers, which will improve the likelihood of engagement post-surgery. Discreet monitoring and follow-up could significantly improve outcome data.
- Professor Kevan Wylie is consultant in sexual medicine at the Porterbrook Clinic, Sheffield
- Bockting W, Knudson G, Goldberg JM. Counselling and mental health care of transgender• Sometimes used as an umbrella to describe anyone whose identity or behaviour falls outside of stereotypical gender norms. More narrowly defined, it refers to an individual whose gender identity does not match their assigned birth gender. Being transgender does not imply any specific sexual orientation (attraction to people of a specific gender). Therefore, transgender people may additionally identify with a variety of other sexual identities as well.
• An umbrella term used to include transsexual people, transvestites and cross-dressers, as in “the transgender community.”
• This is an umbrella term that applies to anyone who does not feel that their gender identity (e.g., identifying as male, female, or other) matches their anatomical/bio- logical sex.
• An umbrella term for people whose gender identity and/or expression differs from that of their sex assigned at birth. Transgender people may or may not alter their bodies to better fit with their gender identity through means such as hormones or surgery. Some intersex people identify as transgender but the two are not the same. Identities such as transsexual or transvestite are distinct sub-categories of transgender and should not be used as synonyms. Should only be used as an adjective e.g. ‘transgender people’. The word “Transgendered” is used by some people but its use is discouraged.
adults and loved ones. Vancouver Coastal Health Authority, Vancouver, Canada, 2006. ↩ - Futterweit W. Endocrine therapy of transsexualism• This term is used to describe a person who has “transitioned”, or is in the process of “transitioning”, or intends to transition from male to female or female to male. For a transsexual person, the process of “transitioning”, may involve a variety of treatments including: hormone therapy, surgery and hair removal. People who have transitioned do not necessarily identify as trans any longer; they may identify as simply a man or a woman. Some transsexual people may not transition due to family or other social constraints.
• When people complete their transition, they may no longer regard themselves as part of the trans umbrella. They might consider having been transsexual to just be an aspect of their medical history which has now been resolved and so is no longer an issue in their life. In such cases, they simply describe themselves as men or as women and it is most disrespectful to insist on calling them trans, transgender or transsexual against their wishes.
and potential complications of long-term treatment. Arch SexBiological attributes and legal categories used to classify humans as male, female, intersex or other categories, primarily associated with physical and physiological features including chromosomes, genetic expression, hormone levels and function, and reproductive/sexual anatomy. Behav 1998; 27: 209-26. ↩ - Moore E, Wisniewski A, Dobs A. Endocrine treatment of transsexualThis is typically used to describe people who identify as transgender who are transitioning toward the gender with which they identify. This may include socially presenting (e.g., clothing, hair, mannerisms, overall gender expression) as the gender with which they identify, or it may include more extensive changes like taking hormones and/or surgical procedures to modify their body. people: a review of treatment regimens, outcomes, and adverse effects. J Clin Endocrinol Metab 2003; 88: 3467-73. ↩
- Scarabin PY, Oger E, Plu-Bureau G. Differential association of oral and transdermal oestrogen-replacement therapy with venous thromboembolism risk. Lancet 2003; 362: 428-32. ↩