期刊更正标志性瑞典研究：重新分析发现性别手术对心理健康没有益处

一项关键研究的更正：没有证据表明“性别确认”手术可以改善心理健康

Authors: Society for Evidence-Based Gender Medicine (SEGM)
Journal: Society for Evidence-Based Gender Medicine (SEGM)
Year: 2020
Source: segm.org/ajp_correction_2020

Summary

A 2019 Swedish study by Bränström and Pachankis in the American Journal of Psychiatry was widely reported as showing that gender surgery improves mental health. People whose surgery was longer ago were less likely to be getting mental health care in 2015; hormones showed no such link. After critical letters, the journal asked statisticians to review it and asked the authors to compare 1,018 surgery patients with 1,018 similar people who had not had surgery. That comparison showed 'no advantage of surgery'. The 2020 correction called the pro-surgery conclusion 'too strong' and fixed a 48% vs 37.9% error. This SEGM (Society for Evidence-Based Gender Medicine) article explains the correction accurately. But the new comparison was an afterthought, not part of the original plan, the paper was not withdrawn, and SEGM is a side in the debate.

Key findings

2019年的原始研究使用了涵盖970万人的瑞典国家健康记录，其中包括2005年至2015年间被诊断为性别不一致的2,679人，并考察了单一年份（2015年）的心理健康治疗情况。
研究发现使用激素的年数与心理健康治疗之间没有关联，但自上次手术以来每过一年，接受治疗的几率约降低8%。作者称这支持提供手术。
在瑞典、挪威、美国和英国的研究人员写来批评信件之后，期刊编辑下令进行两次统计审查，并要求作者将1,018名手术患者与1,018名相似的未手术患者进行比较。
2020年8月的更正称，这一比较显示，在情绪或焦虑就诊、处方，或自杀未遂后的住院方面，“手术没有优势”。
更正称支持手术的结论“过于强烈”，因为该研究没有向前追踪人群，也没有随机分配治疗。它还把接受手术者的比例从48%更正为37.9%。
该论文没有被撤回。它被重新发布并附加了说明，作者在回复中为手术后时间的发现辩护，并认为未手术的患者是不合适的比较组。
在新的比较中，手术患者因焦虑接受治疗的可能性略高，自杀未遂后的住院为13次对7次。这一差异很可能是偶然的，SEGM表示这并不说明有危害。
大多数手术是近期进行的：1,018人中超过75%是在2015年前三年内手术，只有19人是10年或更早之前，因此该研究对长期结果几乎没有说明。

Abstract

In October 2019, the American Journal of Psychiatry (AJP) published a study from the Karolinska Institute in Sweden, and the Yale School of Public Health which reported that “gender-affirming" surgeries for gender dysphoric patients are associated with improved mental health outcomes. Looking at mental health utilization in the year 2015, a retrospective analysis showed that the more time passed since surgery, the fewer mental services were utilized by patients, with an average 8% reduction in mental health utilization for each year following surgery. From this, the study concluded that surgery has a beneficial effect on mental health, and that benefits continue to accrue over time. However, following a reanalysis of the data, this conclusion has now been officially corrected to indicate that there is “no advantage of surgery.”

Conclusion

After reanalysis with a control group comparing gender dysphoric patients who received surgery to those who did not, no statistically significant difference was found in mental health utilization measures. The AJP correction stated the original conclusion that 'the longitudinal association between gender-affirming surgery and lower use of mental health treatment lends support to the decision to provide gender-affirming surgeries' was too strong. The Society for Evidence-Based Gender Medicine (SEGM) concluded that no mental health benefit of gender-affirming surgery was demonstrated in the corrected analysis.

Methodological limitations

Written by a group with a position: This record is SEGM's explanation, not the correction itself. SEGM argues for caution in gender medicine and notes that some of its advisers wrote the critical letters, so its framing should be read with that in mind.
New comparison was an afterthought: The surgery vs no-surgery comparison was not part of the original question. The correction notes that the groups may differ in several other ways, so the 'no difference' result is also not strong proof either way.
Comparison group mixes different people: The authors argued that people diagnosed with gender incongruence who had not had surgery include many who never wanted it. So finding no difference does not show surgery has no benefit for those who seek it, a point SEGM accepts.
Corrected, not withdrawn: The journal corrected the conclusion and reposted the article, but did not withdraw the time-since-surgery link, which the authors stood by. Saying 'the study was wrong' goes further than the formal correction.
One-year snapshot: Both analyses looked at mental health treatment in 2015 only, comparing different people at different times since surgery rather than following the same people over time. They cannot show change in any one person.
Indirect measures: Visits, prescriptions and hospital stays measure use of services, not symptoms or quality of life. Required mental health assessments before surgery may have pushed up service use around the time of surgery.
Deaths and moves abroad missed: Only people alive and living in Sweden in 2015 were included. If people died, including by suicide, after surgery, those with surgery long ago would look healthier than they were. The authors admitted this.
Patients changed over time: More recent patients were younger, more often born female and more often had other mental health problems. This alone could explain why people with older surgeries used fewer services, regardless of surgery.
Many tests, one hit: The single positive result in the original was only just clear of chance, and came alongside several other measures tested without allowing for the extra chance of a fluke, as letter writers pointed out.
Doubtful 'lost patients' claim: SEGM suggests about 90% of patients were 'lost', because only 19 had surgery before 2005 compared with 324 in an earlier Swedish study. But the study only included people diagnosed from 2005 to 2015, so people treated earlier were mostly outside the study rather than lost.
Too few suicide-related cases: Hospital stays after suicide attempts (13 vs 7) are too few to support conclusions either way, and the new comparison was too small to test this properly.

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