Gender dysphoria (GD) describes the distress a person experiences due to a mismatch between their gender identity and the sex they were assigned at birth. For decades, the primary treatment pathway for individuals with persistent GD has involved gender-affirming medical interventions, often including hormone therapy and surgery. Understanding the long-term well-being and health outcomes for this population is important for evidence-based care. Population-level studies with extensive follow-up periods are necessary to provide a complete picture of the post-treatment experience.
Identifying the Landmark Research
A highly influential piece of research that provided a long-term look at outcomes was a 2011 publication in the journal PLoS One by Cecilia Dhejne and colleagues. Titled “Long-Term Follow-Up of Transsexual Persons Undergoing Sex Reassignment Surgery: Cohort Study in Sweden,” the paper drew significant attention for its comprehensive data. The study’s ability to track individuals over many years is possible due to Sweden’s robust national registry system. This system allows researchers to link demographic data, medical records, and judicial information across the entire population, making the study a valuable resource for examining health trajectories.
Methodology and Cohort Definition
The study was structured as a population-based, matched cohort analysis utilizing data collected from Swedish national registers. The researchers identified 324 individuals who were diagnosed with transsexualism, had undergone sex reassignment surgery, and had received a legal change of sex status between 1973 and 2003. This treated cohort included 191 male-to-females and 133 female-to-males.
The core of the methodology involved comparing the outcomes of this cohort to those of the general Swedish population. For each sex-reassigned individual, the researchers selected ten age- and birth-sex-matched controls from the population registers, creating a comparison group of 3,240 people. The average follow-up time for the treated group was approximately 11.4 years for all-cause mortality, though some individuals were tracked for up to 30 years. Reliance on national registers allowed for the adjustment of pre-existing factors, such as prior psychiatric morbidity, which is a common confounder in studies of this population.
Key Findings on Long-Term Outcomes
The analysis provided specific statistical measures, comparing the post-treatment cohort to the general population controls. The primary finding indicated that the overall mortality rate for sex-reassigned individuals was significantly higher than for the population controls. The adjusted Hazard Ratio (aHR) for all-cause mortality was 2.8, meaning the risk was almost three times greater.
A disproportionate component of this increased mortality risk was linked to death by suicide. The study reported a highly elevated adjusted Hazard Ratio for death by suicide at 19.1 when compared to their birth-sex controls. This suggests a nearly twenty-fold increase in the risk of completed suicide within the cohort post-treatment.
Individuals in the treated cohort also showed substantially higher rates of psychiatric morbidity. The risk of being hospitalized for any psychiatric disorder was almost three times higher than the control population (aHR 2.8). Furthermore, the risk for non-fatal suicide attempts was also greatly increased (aHR 4.9), indicating the risk was nearly five times higher. These statistical findings persisted even after the researchers accounted for pre-existing psychiatric conditions and immigrant status.
Interpretation and Contextual Limitations
The study authors acknowledged that the elevated risks for mortality and psychiatric morbidity persisted in the sex-reassigned group despite having received treatment. A significant limitation is that the study could not compare the outcomes of the treated cohort to a similar group of individuals with GD who did not receive medical intervention. Therefore, the study design could not determine whether the treatment itself was effective, only that the risks remained high after treatment.
The temporal context of the data is also an important consideration. The cohort includes individuals treated between 1973 and 2003, a period when diagnostic criteria, surgical techniques, and post-operative care protocols were significantly different from contemporary standards. The authors suggested that discrimination, marginalization, and social stigma likely contribute to the persistently high rates of adverse outcomes.
The researchers concluded that while gender reassignment may alleviate gender dysphoria for many, it was not sufficient to reduce the high rates of morbidity and mortality to that of the general public. The findings highlight that post-treatment individuals remain a vulnerable group requiring long-term psychiatric and somatic follow-up care. This suggests that the vulnerability associated with the condition and its social context continues long after medical intervention.