Bränström 2019 — corrective update

In 2019, Bränström and Pachankis published a Swedish population study in The American Journal of Psychiatry whose abstract concluded that gender-affirming surgery was associated with a reduction in mental health care utilization.

Original claim

In 2019, Bränström and Pachankis published a Swedish population study in The American Journal of Psychiatry whose abstract concluded that gender-affirming surgery was associated with a reduction in mental health care utilization.

2020 correction

Following a reanalysis by independent researchers and at the request of the journal's editors, the authors published a correction in 2020. The corrected analysis found no statistically significant difference between the treated and untreated groups in mental health outcomes.

Meaning

The case is often cited as an illustration of the difficulty of making causal claims about the effectiveness of gender-affirming procedures based on observational data. The question of who bears the burden of proof when outcomes are uncertain is discussed on transethiek.nl.

Study design

The researchers used Swedish population registers. They selected 2,679 people who had received a diagnosis of gender incongruence between 2005 and 2015 and examined how often they received care for mood and anxiety disorders in 2015, were prescribed medication for these conditions, or were admitted to hospital following a suicide attempt. For hormone treatment, they found no association with lower care utilization. For surgery, such an association did appear to exist: the longer ago the surgery had taken place, the less care was used.

What went wrong

After publication, the journal received a series of letters from researchers. They pointed out that the study had not compared people who had undergone surgery with people with the same diagnosis who had not undergone surgery. Such a comparison is necessary to say anything about the effect of the surgery. At the journal's request, the authors subsequently carried out the analysis. The difference was not demonstrable. In the August 2020 correction, they wrote that the conclusion that surgery reduced care utilization had been too strong.

Aftermath

The original conclusion received considerable media attention and was cited as evidence that surgery improves mental health. The correction received far less attention, and the original version is still regularly cited. The course of events shows why a single study, and especially its abstract, says little without examining the underlying analysis. See also bias in gender research and the earlier Swedish study by Dhejne from 2011.

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