An observational study in Transgender Individuals and Gender Incongruence, sponsored by University Hospital, Basel, Switzerland. Recruiting at 3 sites in Switzerland. Open to participants aged 16 Years and older. Per ClinicalTrials.gov, last updated 2026-06-30.
Sponsored by University Hospital, Basel, Switzerland · Observational
The goal of this observational study is to understand the factors influencing the well-being and health of transgender and gender-diverse (TGD) individuals undergoing gender-affirming therapies in Switzerland. The study population includes TGD individuals aged 16 and older, at various stages of their medical transition, including those who have discontinued or detransitioned.
The main question is:
What are the key factors influencing the well-being and health outcomes of transgender and gender-diverse individuals undergoing gender-affirming therapies?
Researchers will compare health outcomes across different subgroups, such as those at different stages of transition or detransition, to examine the effects of gender-affirming therapies.
Participants will:
Complete electronic questionnaires assessing gender congruence, quality of life, mental health, and other outcomes.
Provide biological samples (e.g., blood, urine, stool, and skin swabs) for laboratory analysis.
Undergo clinical evaluations related to endocrinology, fertility, dermatology, and urology as part of their routine follow-up.
85 studies on the registry are indexed under Gender Dysphoria; 38 are open to participants now.
This study's planned enrollment of 600 is above the median of 100 across 52 observational studies indexed under Gender Dysphoria.
Browse Gender Dysphoria studies →University Hospital, Basel, Switzerland is the lead sponsor of 990 studies on the registry; 189 are open to participants now.
Counted across the registry records on this site, refreshed daily.
The project population will consist of TGD individuals above age 16 who are diagnosed with gender incongruence and who wish medical transition or are on medical transition (at any stage of their transition, including individuals who interrupt/-ed medical transition or detransition/-ed). Recruitment for the study will initially take place at the University Hospital of Basel and the Cantonal Hospital of Luzern, with plans to expand to additional centers (e.g. University Hospital of Zurich, University Hospital of Geneva and Cantonal Hospital of St Gallen) as the study progresses. The study targets individuals at various stages of medical transition, including those initiating, continuing, or discontinuing gender-affirming therapies. Efforts will ensure inclusion of all gender identities to comprehensively address their unique healthcare needs.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Individuals who present before they start GAHT are included in group A
Other: Group A (start of GAHT)
Individuals who are already on GAHT are included in group B
Other: Group B (on-going GAHT)
Individuals who undergo gender affirming surgery are (additionally or exclusively) included in group C
Other: Group C (GAS)
The study program consists of assessments at baseline (before the start of GAHT) and subsequent follow-up visits scheduled at routine intervals which are typically every three months for the first year, every six months for the second year and every twelve months thereafter. Participants' data collection includes a mix of digital and in-person methods. Demographical information, clinical and laboratory parameters such as hormone levels which are part of standard clinical care
The study program consists of a yearly assessment as part of the long-term routine follow-up. Participants' data collection includes a mix of digital and in-person methods. Demographical information, clinical and laboratory parameters such as hormone levels which are part of standard clinical care
If GAS is administered, additional assessments are performed preoperatively, and postoperatively in analogy with routine clinical visits, e.g. one week after surgery and then three, six and twelve months later (then once yearly) (e.g. type of surgery, outcome, patient' satisfaction). If participants undergo gender-affirming genital surgery, a genital swab and urine analysis (from the urine sample taken for routine testing) will additionally be performed for microbiome analyses as part of the study assessment.
Gender Congruence as Assessed by Gender Congruence and Life Satisfaction Scale (GCLS)
The Gender Congruence and Life Satisfaction Scale (GCLS) is a validated outcome measure specifically developed for transgender individuals to assess distress and unhappiness with experienced gender and body, regardless of gender assigned at birth or gender identity. The scale ranges from \[insert range, e.g., 0-100\], with higher scores indicating greater gender congruence and life satisfaction, and lower scores reflecting greater distress and unhappiness. It is suitable for binary and nonbinary individuals seeking gender-affirming care.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Gender identity
The gender identity is assessed using a study-specific questionnaire to determine the percentage of different gender identities (e.g. binary, non-binary) and change of gender identity over time
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Difference in Gender Affirming Hormone Therapy (GAHT) regimens
The reported value will be the number and percentage of participants receiving each documented GAHT regimen category at each routine assessment, stratified by self-reported gender identity.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Decision regret scale
The Decision Regret Scale is a validated tool that is used in this study to measure the regret after detransition. The scale ranges from 0 to 100, with higher scores indicating greater regret and lower scores reflecting less or no regret. It is widely applicable across different healthcare contexts to assess the emotional impact of decision-making.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Body image states scale
The Body Image States Scale is a validated measure that is used in this study to assess an individual's momentary body image satisfaction after detransition. The scale ranges from 0 to X, with higher scores indicating greater body image satisfaction and lower scores reflecting greater dissatisfaction.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Quality of life score
The quality of life is meassured using the EuroQol 5-Dimension 5-Level (EQ-5D-5L) questionnaire.The EQ-5D-5L is a standardized measure, assessing mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. The scale provides a utility score ranging from 0 (equivalent to death) to 1 (perfect health), with higher scores indicating better health-related quality of life.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Treatment Satisfaction Questionnaire for Medication 1.4
To evaluate treatment satisfaction an adapted Treatment Satisfaction Questionnaire for Medication 1.4 (TSQM-1.4) is used. TSQM-1.4 is a validated tool, assessing patients' satisfaction with their treatments across four domains: effectiveness, side effects, convenience, and overall satisfaction. The scale provides scores ranging from 0 to 100 for each domain, with higher scores indicating greater satisfaction.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Beck Depression Inventory-II
The Beck Depression Inventory-II (BDI-II), a validated self-report measure, is used to assess depressive symptoms. The scale ranges from 0 to 63, with higher scores indicating greater severity of depressive symptoms and lower scores reflecting minimal or no depression.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Detransition rate
Detransition is assessed as the percentage of individuals who interrupt or stop therapy over time.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Reasons for stopping/reversing transition
The reasons for stopping/reversing transition is assessed using a questionnaire adapted from MacKinnon et al., 2024 (21 possible reasons for stopping/reversing transition).
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Gender Minority Stress and Resilience Measure
The Gender Minority Stress and Resilience Measure (GMSR) is a validated, assessing experiences of minority stress and resilience factors specific to transgender and gender-diverse individuals. The scale includes multiple subscales with scores reflecting the levels of stress (e.g., discrimination, internalized transphobia) and resilience (e.g., community connectedness, pride). Higher stress subscale scores indicate greater experiences of minority stress, while higher resilience subscale scores reflect stronger protective factors.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Endocrine profiling
Sex hormone are profiled on GAHT and in relation to the different outcome measures
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Blood pressure
Blood pressure is taken (by unattended automated office blood pressure measurement =UAOBPM)
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Body mass index
Body weight is measured and body mass index (BMI) calculated.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Dietary Approaches to Stop Hypertension (DASH) score
Dietary quality is assessed via Dietary Approaches to Stop Hypertension (DASH) scoring on a scale from 1-100, with higher score indicating healthier dietary habits.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Mediterranean Eating Pattern (MEPA) score
Dietary quality is assessed via Mediterranean Eating Pattern (MEPA) scoring on a scale from 1-100, with higher score indicating healthier dietary habits.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Lipid profile
Glucose homesostasis is assessed by measuring blood glucose, HOMA-Index, HbA1C.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Inflammation hsCRP
hsCRP concentration measured in venous blood as part of routine laboratory assessment and reported as a continuous variable
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Inflammation IL-6
Inflammatory markers are assessed including IL-6
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Health risk behaviors
National Health and Nutrition Examination Survey (NHANES) questionnaires assesses smoking, alcohol, physical activity.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Sleep quality
Pittsburgh Sleep Quality Index (PSQI) which ranges from 0 to 21. Higher scores indicate poorer sleep quality, with a score greater than 5 suggesting significant sleep difficulties.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Insomnia
Insomnia Severity Index (ISI) is a self-assessment questionnaire ranging from 0-28, while higher score worse sleep quality
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Scalp hair cortisol concentration measured by liquid chromatography-tandem mass spectrometry
Cortisol concentration measured in a proximal 3-cm scalp hair segment collected from the posterior vertex region
Time frame: Baseline and 12 months after initiation of GAHT
Urinary steroid profile
Steroid profile measured in a 24-hour urine sample to capture integrated steroid excretion over 24 hours.
Time frame: Baseline and 12 months after initiation of GAHT
Immunological parameters cytokine levels
IL-6, TNF-α, IL-1β, IL-10 concentration measured in stored blood samples and reported as a continuous variable.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Immunological parameters antibody levels
Assessment of antibody levels
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Fertility Self-Assessment Responses Assessed Using a SPECTRA-Specific Questionnaire
The reported value will be the number and percentage of participants selecting each response category for prespecified fertility-related items, including fertility intentions, prior fertility preservation, interest in future fertility preservation, and fertility-related counseling needs, as assessed using a SPECTRA-specific self-assessment questionnaire. This study-specific questionnaire is not summarized as a total score.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Tucking practices
The reported value will be the number and percentage of participants who report current tucking practices on the SPECTRA questionnaire.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Sexual Desire
Sexual Desire Inventory (SDI). The scores for the two dimensions of sexual desire are summed up separately. Dyadic sexual desire: Scores will range from 0 to 62; while there is no universally established cutoff score that applies across all populations, higher scores at around 50 and upward indicate hypersexuality in the dyadic dimension. Solitary sexual desire: Scores will range from 0 to 39; while there is no universally established cutoff score that applies across all populations, higher scores at around 31 and upward indicate hypersexuality in the solitary dimension.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Semen Quality Status
The reported value will be the number and percentage of eligible participants in each predefined semen quality category at each assessment time point. Semen quality status will be derived from standard semen analysis parameters according to prespecified laboratory criteria and categorized as normal semen quality, impaired semen quality, severe impairment, azoospermia, or not classifiable due to insufficient sample quality or missing parameters.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Dermatology life quality index
Dermatology life quality index (DLQI) is calculated by adding the score of each question, resulting in a maximum of 30 and a minimum of 0. The higher the score, the more quality of life is impaired. A score higher than 10 indicates that the patient's life is being severely affected by their skin disease.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Visual analogue scale disease activity
disease activity is assessed by Visual analogue scale (VAS)
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Percentage of scalp hairs
Percentage of hairs with reduced caliber assessed using TrichoScan software in a circular 1-cm² scalp area.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Skin aging assessed by VISIA skin analysis
For the detection of skin wrinkles Visia device will be used as standardized photography
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Skin microbiome
Skin swabs from defined sites to perform 16S rRNA amplicon based sequencing of the cutaneous bacterial microbiome
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Prosthesis outcome
In transmen, prosthesis outcome is assessed including complication rates, revision rates, survival rates, patient- and partner-related satisfaction rate e.g. with validated Questionnaire Quality of Life and Sexuality with Penile Prosthesis (QoLSPP)
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Urethral Complication Status Assessed by Clinical Examination
The reported value will be the number and percentage of eligible participants in each predefined urethral complication category at each assessment time point, as assessed by clinical examination and medical record review. Categories will include no urethral complication, urethral stricture, urethral fistula, both urethral stricture and fistula, and other urethral complication. For participants with urethral stricture or fistula, the type of management will be recorded descriptively according to predefined categories, including conservative management, catheter-based management, endoscopic treatment, surgical repair, or other management.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Lower Urinary Tract Symptom Questionnaire
Lower Urinary Tract Symptom Questionnaire is a self-assessment tool to grade lower urinary tract symptoms. It ranges from 0-35, while typically a score of 0-7 indicates mild symptoms, 8-19 moderate symptoms and 20-35 severe symptoms. Higher scores indicate more severe symptoms.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Gut microbiome
Alpha diversity, beta diversity, microbial richness and relative abundance diversity of the gut microbiome measured in stool samples and reported using a predefined diversity index.
Time frame: Baseline; 3, 6, 9, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, and 240 months
Started Apr 2026 (actual). Primary completion is estimated for Jan 2046, 237 months after the start.
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