Long term mental health outcomes of Finnish children evacuated to Swedish families during the second world war and their non-evacuated siblings: cohort study
BMJ 2015; 350 doi: https://doi.org/10.1136/bmj.g7753 (Published 05 January 2015) Cite this as: BMJ 2015;350:g7753
- Torsten Santavirta, assistant professor1,
- Nina Santavirta, associate professor2,
- Theresa S Betancourt, associate professor3,
- Stephen E Gilman, associate professor4
- 1Swedish Institute for Social Research, Stockholm University, SE-10691, Stockholm, Sweden
- 2Institute of Behavioural Sciences, University of Helsinki, Helsinki, Finland
- 3Department of Global Health and Population, Harvard School of Public Health, Boston, MA, USA
- 4Department of Social & Behavioral Sciences and Department of Epidemiology, Harvard School of Public Health, Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
- Correspondence to: T Santavirta torsten.santavirta{at}sofi.su.se
- Accepted 23 November 2014
Abstract
Objectives To compare the risks of admission to hospital for any type of psychiatric disorder and for four specific psychiatric disorders among adults who as children were evacuated to Swedish foster families during the second world war and their non-evacuated siblings, and to evaluate whether these risks differ between the sexes.
Design Cohort study.
Setting National child evacuation scheme in Finland during the second world war.
Participants Children born in Finland between 1933 and 1944 who were later included in a 10% sample of the 1950 Finnish census ascertained in 1997 (n=45 463; women: n=22 021; men: n=23 442). Evacuees in the sample were identified from war time government records.
Main outcome measure Adults admitted to hospital for psychiatric disorders recorded between 1971 and 2011 in the Finnish hospital discharge register.
Methods We used Cox proportional hazards models to estimate the association between evacuation to temporary foster care in Sweden during the second world war and admission to hospital for a psychiatric disorder between ages 38 and 78 years. Fixed effects methods were employed to control for all unobserved social and genetic characteristics shared among siblings.
Results Among men and women combined, the risk of admission to hospital for a psychiatric disorder did not differ between Finnish adults evacuated to Swedish foster families and their non-evacuated siblings (hazard ratio 0.89, 95% confidence interval 0.64 to 1.26). Evidence suggested a lower risk of admission for any mental disorder (0.67, 0.44 to 1.03) among evacuated men, whereas for women there was no association between evacuation and the overall risk of admission for a psychiatric disorder (1.21, 0.80 to 1.83). When admissions for individual psychiatric disorders were analyzed, evacuated girls were significantly more likely than their non-evacuated sisters to be admitted to hospital for a mood disorder as an adult (2.19, 1.10 to 4.33).
Conclusions The Finnish evacuation policy was not associated with an increased overall risk of admission to hospital for a psychiatric disorder in adulthood among former evacuees. In fact, evacuation was associated with a marginally reduced risk of admission for any psychiatric disorder among men. Among women who had been evacuated, however, the risk of being admitted to hospital for a mood disorder was increased.
Footnotes
We thank Lauri Hirvonen and Minna Maier (University of Helsinki) for their assistance with the research; Sanna Malinen, Jukka Mattila, and Satu Nurmi (Statistics Finland); and Jouni Rasilainen (National Institute for Health and Welfare) for help during the data acquisition phase.
Contributors: NS and TS acquired the data. TS designed the study and conducted the statistical analyses. All authors contributed to the interpretation of data and preparation of the manuscript, and approved the final version. TS is guarantor.
Funding: This work was supported by the Academy of Finland, National Institutes of Health (grant MH087544), and the Signe and Ane Gyllenberg Foundation. TS received additional support from the Tore Browaldh Foundation and the Siamon Foundation.
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: this work was supported by the Academy of Finland, the National Institutes of Health (grant MH087544), and the Signe and Ane Gyllenberg Foundation. TS received additional support from the Tore Browaldh Foundation and the Siamon Foundation; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.
Ethical approval: This study was approved by the ethics committees of the National Institute of Health and Welfare (THL/1653/5.05.00/2012) and of Statistics Finland (TK53-1500-10). Data were linked with the permission of the appropriate authorities.
Data sharing: The analytic dataset and statistical code are available at Statistics Finland but permission to use the data must be granted by Statistics Finland. Permission applications to access data are available at www.tilastokeskus.fi/meta/tietosuoja/kayttolupa_en.html.
Transparency: The lead (TS) affirms that this manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned have been explained.
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