Swiss ProspectivE Cohort of TRAnsgender and Gender Diverse Individuals - The SPECTRA Study (SPECTRA)

Swiss Prospective Cohort of TRAnsgender and Gender Diverse Individuals - The SPECTRA Study

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.

Study Overview

• Status: Recruiting
• Conditions: Gender Incongruence; Transgender Individuals
• Intervention / Treatment: Other: Group A (start of GAHT); Other: Group B (on-going GAHT); Other: Group C (GAS)

• Study Type: Observational
• Enrollment (Estimated): 600

Contacts and Locations

• Study Contact: Name: Hüseyin Cihan, Dr.; Email: hueseyin.cihan@usb.ch
• Study Contact Backup: Name: Bettina Winzeler, PD Dr.; Phone Number: +41 61 556 50 75; Email: bettina.winzeler@usb.ch

Study Locations

• Switzerland
  • Basel, Switzerland, 4031
    • Recruiting
    • University Hospital of Basel
    • Contact: Bettina Winzeler, PD Dr. med.; Phone Number: +41 61 556 50 75; Email: bettina.winzeler@usb.ch
  • Lucerne, Switzerland, 6000
    • Not yet recruiting
    • Cantonal Hospital of Lucerne
    • Contact: Lea Slahor, KD Dr.; Phone Number: +41 205 51 03; Email: lea.slahor@luks.ch

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

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.

Description

Inclusion Criteria:

• Age 16 years and above.
• Established diagnosis of gender incongruence
• Indication for gender affirming therapy or ongoing or discontinued gender affirming therapy

Exclusion Criteria:

• Unable to give informed consent
• Missing commitment or ability to study protocol adherence

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Group A: Cohort of Transgender and Gender Diverse individuals in Switzerland; Individuals who present before they start GAHT are included in group A	Other: Group A (start of GAHT); 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
Group B: Cohort of Transgender and Gender Diverse individuals in Switzerland; Individuals who are already on GAHT are included in group B	Other: Group B (on-going GAHT); 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
Group C: Cohort of Transgender and Gender Diverse individuals in Switzerland; Individuals who undergo gender affirming surgery are (additionally or exclusively) included in group C	Other: Group C (GAS); 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	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

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
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	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.	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.	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.	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.	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.	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.	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.	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).	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.	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	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)	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.	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.	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.	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.	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	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	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.	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.	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	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	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.	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.	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	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.	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.	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.	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.	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.	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)	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.	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	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	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)	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.	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.	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.	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

Collaborators and Investigators

• Sponsor: University Hospital, Basel, Switzerland
• Collaborators: University of Luzern
• Investigators: Principal Investigator: Bettina Winzeler, PD Dr., University Hospital Basel, Department of Endocrinology

Study record dates

Study Major Dates

• Study Start (Actual): April 20, 2026
• Primary Completion (Estimated): January 1, 2046
• Study Completion (Estimated): January 1, 2046

Study Registration Dates

• First Submitted: January 8, 2025
• First Submitted That Met QC Criteria: January 8, 2025
• First Posted (Actual): January 14, 2025

Study Record Updates

• Last Update Posted (Actual): May 5, 2026
• Last Update Submitted That Met QC Criteria: April 28, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Gender Affirming Hormone Therapy (GAHT); Gender Affirming Surgery (GAS); Transgender and Gender Diverse (TGD)
• Additional Relevant MeSH Terms: Mental Disorders; Sexual Dysfunctions, Psychological; Gender Dysphoria
• Other Study ID Numbers: 2025-00514; kt24Winzeler

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No