Skip to main content Accessibility help
×
Home
Hostname: page-component-55b6f6c457-rfl4x Total loading time: 0.425 Render date: 2021-09-26T13:43:52.926Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "metricsAbstractViews": false, "figures": true, "newCiteModal": false, "newCitedByModal": true, "newEcommerce": true, "newUsageEvents": true }

Abortion and mental health: guidelines for proper scientific conduct ignored

Published online by Cambridge University Press:  02 January 2018

Louise M. Howard
Affiliation:
Section of Women's Mental Health, PO31, Institute of Psychiatry, King's College London, UK. Email: louise.howard@kcl.ac.uk
Melissa Rowe
Affiliation:
Section of Women's Mental Health and Women's Health Academic Centre KHP, Institute of Psychiatry, King's College London, UK
Kylee Trevillion
Affiliation:
Section of Women's Mental Health and Women's Health Academic Centre KHP, Institute of Psychiatry, King's College London, UK
Hind Khalifeh
Affiliation:
Mental Health Sciences Unit, Faculty of Brain Sciences, University College London, UK
Trine Munk-Olsen
Affiliation:
National Center for Register-Based Research, Faculty of Social Sciences, Aarhus University, Denmark
Rights & Permissions[Opens in a new window]

Abstract

Type
Columns
Copyright
Copyright © Royal College of Psychiatrists, 2012 

We have serious concerns about the methodology of the quantitative synthesis by Coleman Reference Coleman1 and want to highlight these to prevent readers and policy makers drawing erroneous conclusions, in particular the incorrect statement that ‘nearly 10% of the incidence of mental health problems was shown to be attributable to abortion’.

This quantitative synthesis and meta-analysis did not follow the robust methodologies now generally accepted for systematic reviews. Reference Stroup, Berlin, Morton, Olkin, Williamson and Rennie2 There is no detail of the search strategy including search terms; the strategy is not comprehensive (only two databases included); other strategies to search the literature, including citation tracking, hand searching and contacting authors and experts in the field to try to minimise publication bias, were not carried out; and there was no assessment or rating of the quality of included studies, so that only those of at least reasonable quality are included in the meta-analysis. This is particularly important here as many of the primary studies included in this review have significant methodological limitations, including non-prospective design, non-standardised measures of mental disorders, lack of adjustment for pre-existing mental illness, lack of adjustment for other key confounders (e.g. social deprivation), non-comparability of exposed and non-exposed groups, and selection bias. This is especially concerning, given that previous reviews raised serious methodological concerns about some of the included studies, and came to different conclusions when these were excluded from analyses. Reference Major, Appelbaum, Beckman, Dutton, Russo and West3Reference Robinson, Stotland, Russo, Lang and Occhiogrosso5 Furthermore, results from several of the included studies linking abortion to mental health problems have since been re-analysed by other researchers. These studies, using the same data, have less biased sample selection techniques and control for pre-pregnancy factors known to influence poor mental health outcomes (i.e. rape history) and have found no significant links between abortion and subsequent poor mental health. Reference Schmiege and Russo6,Reference Steinberg and Russo7

A recent population-based cohort study conducted in Denmark published in the New England Journal of Medicine this year confirmed this. Munk-Olsen et al Reference Munk-Olsen, Laursen, Pedersen, Lidegaard and Mortensen8 reported no difference between the incidence of first psychiatric contact before and after abortion. Importantly, the incidence of psychiatric contact is higher among women who underwent abortion; this is the result of a selection phenomenon and not a causal association because this relationship is evident before the abortion occurred. Reference Munk-Olsen, Laursen, Pedersen, Lidegaard and Mortensen8 This is evidence that women having induced abortions constitute a population with higher pre-existing psychiatric morbidity.

Study selection and evaluation should be carried out by two independent raters; the Coleman review was carried out by one author only. Of the 22 papers included, 11 were authored by Coleman, the author of the review. This is a conflict of interest, and undermines the author’s ability to critically review the primary studies.

Finally, the synthesis of the data and the summary statistics are flawed. The criteria for synthesising data meant that several effect measures were included from the same study. Eleven of the included studies contributed more than one effect measure, with two studies contributing four measures each. Despite the clustering of effect measures by study, they are analysed as independent measures. This is an important limitation, since the use of several effect measures from a flawed study can magnify the bias.

Most importantly for readers of this study to know, is the erroneous conclusions drawn by the author regarding the population attributable risk (PAR). The underlying assumptions for estimating PAR include that there is a causal relationship between the risk factor (abortion) and the disease (mental ill health) and that there is independence of the considered risk factor from other factors that influence disease risk. Reference Rockhill, Newman and Weinberg9 These assumptions are clearly not met in this review and therefore it is completely inappropriate to calculate a PAR from these data.

Abortion and mental health is a politicised issue – it is therefore essential that research in this field is methodologically robust.

Footnotes

Declaration of interest

T.M.-O. was the lead author of the population-based cohort study cited in this letter.

References

1 Coleman, PK. Abortion and mental health: quantitative synthesis and analysis of research published 1995–2009. Br J Psychiatry 2011; 199: 180–6.CrossRefGoogle ScholarPubMed
2 Stroup, DF, Berlin, JA, Morton, SC, Olkin, I, Williamson, GD, Rennie, D, et al. Meta-analysis of observational studies in epidemiology: a proposal for reporting. JAMA 2000; 283: 2008–12.CrossRefGoogle Scholar
3 Major, B, Appelbaum, M, Beckman, L, Dutton, MA, Russo, NF, West, C. Report of the APA Task Force on Mental Health and Abortion. American Psychological Association, 2008.Google Scholar
4 Charles, VE, Polis, CB, Sridhara, SK, Blum, RW. Abortion and long-term mental health outcomes: a systematic review of the evidence. Contraception 2008; 78: 436–50.CrossRefGoogle Scholar
5 Robinson, GE, Stotland, NL, Russo, NF, Lang, JA, Occhiogrosso, M. Is there an ‘abortion trauma syndrome'? Critiquing the evidence. Harv Rev Psychiatry 2009; 17: 268–90.CrossRefGoogle Scholar
6 Schmiege, S, Russo, NF. Depression and unwanted first pregnancy: longitudinal cohort study. BMJ 2005; 331: 1303.CrossRefGoogle ScholarPubMed
7 Steinberg, JR, Russo, NF. Abortion and anxiety: what's the relationship? Soc Sci Med 2008; 67: 238–52.CrossRefGoogle ScholarPubMed
8 Munk-Olsen, T, Laursen, TM, Pedersen, CB, Lidegaard, Ø, Mortensen, PB. Induced first-trimester abortion and risk of mental disorder. N Engl J Med 2011; 364: 332–9.CrossRefGoogle ScholarPubMed
9 Rockhill, B, Newman, B, Weinberg, C. Use and misuse of population attributable fractions. Am J Public Health 1998; 88: 15–9.CrossRefGoogle ScholarPubMed
Submit a response

eLetters

No eLetters have been published for this article.
You have Access
6
Cited by

Send article to Kindle

To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Abortion and mental health: guidelines for proper scientific conduct ignored
Available formats
×

Send article to Dropbox

To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

Abortion and mental health: guidelines for proper scientific conduct ignored
Available formats
×

Send article to Google Drive

To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

Abortion and mental health: guidelines for proper scientific conduct ignored
Available formats
×
×

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *