Author's response to reviews Title:A prospective cohort study of depression in pregnancy, prevalence and risk factors in a multiethnic population Authors: Nilam Shakeel MD (nilam.shakeel@medisin.uio.no) Malin Eberhard-Gran MD, Phd (malin.eberhard-gran@fhi.no) Line Sletner MD (line.sletner@medisin.uio.no) Kari Slinning Phd (kari.slinning@icloud.com) Egil Wilhelm Martinsen Phd (e.w.martinsen@medisin.uio.no) Ingar Holme Professor (UXGAHO@ous-hf.no) Anne Karen Jenum Dr.med., MHP, postdoc (a.k.jenum@medisin.uio.no) Version:2Date:14 October 2014 Author's response to reviews: see over
University of Oslo Faculty of Medicine Nilam Shakeel Institute of Health and Society, Department of General Practice, Faculty of Medicine, University of Oslo, P.O.Box 1130 Blinderen, 0318 Oslo, Norway Dear Mr Jason Pepito and Dr Robert Powers October 14 th, 2014 Editorial Office of BMC Pregnancy and Childbirth Thank you very much for your comments and those of the reviewers as well as the opportunity to revise the paper A prospective cohort study of depression in pregnancy; Prevalence and risk factors in a multi-ethnic population. The reviewers comments are greatly appreciated, and we are pleased to have the opportunity to revise and resubmit our work to BMC Pregnancy and Childbirth. This document lists each of the reviewers comments and how we have revised the manuscript in response to them. We have tracked our changes to the manuscript in red print. We believe the manuscript has benefitted considerably from the reviewers input, for which we are grateful, and we hope that it is now acceptable for publication. Kindly advise if additional revisions are required or if you have any questions regarding the manuscript. Thank you again for considering our work for publication in BMC Pregnancy and Childbirth. Yours sincerely Nilam Shakeel PhD student Anne Karen Jenum Professor, MD, PhD Faculty of Medicine, University of Oslo Postal address: E-mail: www.med.uio.no
2 Referee 1 1) The paper is well written and presented. The data certainly addresses factors associated with depression and takes into account ethnicity. The findings around factors associated with depression are not too surprising and confirm previous studies. However, the authors have attempted to include more socio-economic indicators. The findings around ethnic minorities and their greater risk of depression is interesting and important. Thank you for your positive comments. 2) The discussion section could be strengthened. How do these findings compare to published data from the countries that the ethnic minorities originate from - are they higher? Thank you for your important comment. Before submitting the paper, we searched PubMed for articles about the prevalence of depression in pregnancy in the same countries of origin as our ethnic minority populations. Generally, we found a lack of studies about depression in pregnancy in these countries. We restricted our search to studies using the EPDS and included most of the identified studies in the discussion. We have now repeated the search and have identified an additional study from Punjab, where most Pakistanis in Norway originally emigrated from, that we had previously missed; this study reported the prevalence to be 75.1 percent [1]. This reference has now been included in the discussion. All published studies from Pakistan report higher prevalence rates than our findings for South Asians, as was also the case for studies from the Middle East and Sri Lanka. Studies from Pakistan and Turkey using CES-D, HADS or the Beck Depression Inventory scale report even higher rates, with prevalence up to 11 percent and 80 percent [2-5]. The context is definitely different with other types of concerns reported such as not having any live births, participants roles in decision-making, domestic violence, unplanned pregnancy and pregnancy-related physical symptoms. We have not, however, included studies about the prevalence of depression in pregnancy in our paper using other instruments, such as CES-D, HADS or the Beck Depression Inventory scale, because this makes direct comparison difficult. 3) How are findings relevant to policy or intervention development in Norway and other European countries, in particular, addressing ethnic minority public health issues (social integration, use of health services, etc) Thank you for your important comment. We have now included this aspect in the last paragraph in the discussion.
3 Referee 2 This study deals with an important topic of the prevalence of depression in pregnancy and associations with ethnicity and other risk factors in a Norwegian sample of 749 pregnant women (59% ethnic minorities). Having completed my analysis of the manuscript, I must express a Negative judgment for the following reasons: 1) In the Background section, the literature review lacks significant and current bibliographic citations, such as: 1. Studies carried out in the UK, Canada and Australia regarding samples of women of diverse ethnicity who reside in those countries. We appreciate this point and have now added some references in the introduction and the discussion. See also our answer to referee 1, point 2. We have further added one Swedish study [6]. 2) Elements of the current scientific debate concerning the influence of cultural context of membership and/or origin on women s perinatal mental health. We are sorry that we are not quite sure we have understood which issues the referee wants us to discuss here. We have previously pointed to the stressors that immigrants are exposed to before and during migration and after resettlement, such as lack of social integration, language problems, exposure to racism, unhealthy nutrition and poor housing conditions. These factors may adversely affect their mental health, placing ethnic minorities at higher risk for mental health problems. Another aspect is a potential perceived tension between cultures more dominated by collective values and the individualistic Western societies. Bhugra [7, 8] has presented a model for evaluating mental distress in immigrants; when there is congruency between one s own preferences and the area of residence, living in neighbourhoods with many others from the same culture may be protective compared to living relatively alone in an affluent district. However, for an immigrant who does not share the collective values of his or her group, living among more traditionally oriented family members or neighbours may represent an extra burden due to social control mechanisms. In some ethnic groups, cultural practices related to care for women during pregnancy and the postpartum period [9] differ from contemporary values in Europe. For instance, it is common to take extra care for pregnant and postpartum women, such as making food for them, not allowing them to do housework or physical exercise and to place greater emphasis on rest for these women. In addition, some women move back to their mothers house to receive extra care. Not having all these facilities or being close to their extended family can act as an extra stressor that can affect mental and emotional health. Several sentences about these points have now been added to the introduction. 3) Beyond these aspects, the major criticism that arises, however, is the choice of the manuscript s authors with respect to the EPDS cut-off score used as a measure for depression. The study in
4 question detects the symptomatological level of depression of the PREGNANT women by administering the EPDS. In support of their use of that instrument however, the authors cite only the validation of the EPDS as used in a sample of POSTPARTUM Norwegian women (see Eberhard-Gran et al.2001; Berle et al., 2003). Has a validation of the EPDS in pregnant Norwegian women ever been carried out? In the manuscript, there is in fact no bibliographic citation that gives an adequate guarantee that the EPDS can be considered a reliable instrument when administrated during pregnancy, or even that the EPDS has been used in previous studies involving pregnant Norwegian women or pregnant women of different ethnicities resident in that Scandinavian country. Thank you for your comments and your question. The EPDS has previously been thoroughly validated for use in postnatal, non-postnatal [10] as well as in pregnant women [11-13]. The EPDS has shown good psychometric properties among postnatal Norwegian women, with satisfactory measures of reliability, including a Cronbach s alpha of 0.81 and a test-retest correlation of 0.74 [14]. High test-retest reliability (0.81) has also been demonstrated in other pregnant populations [11]. The EPDS has been used previously for pregnant women in numerous Norwegian studies [15-24], including one recently published in BMC Pregnancy and Childbirth [25]. We have also added these sentences in the method section. In that regard, it should be said, however, that at this time in the international scientific literature there is a dearth of reported studies carried out in other than Western cultures that address the validation of the use of the EPDS during pregnancy. The authors, meanwhile, have adopted an identical EPDS cut-off score of # 10 for all of the pregnant women in the study, notwithstanding the Arabic, Somali, Tamil, Turkish, Urdu and Vietnamese origin of some subjects. In some local studies published in international scientific journals it is possible, though, to find reference to the validity of the EPDS in postpartum Arabic women using an EPDS cut-off score of 12 (Ghubash et al., 1997; Agoub et al., 2005); of 13 (Al Hinai et al., 2014); as well as #13 (Green et al. 2006). At the same time, in validating the EPDS in British Pakistani pregnant women, Husain and colleagues (2014) used a cut-off point of 8; Shah and colleagues, meanwhile, used a score of 13 or greater on the EPDS to indicate depression status in pregnant women from Northern Pakistan, and in Caucasian and Aboriginal women from Saskatchewan, Canada. In conclusion, the use of a single EPDS cut-off score for all of the women involved in the study, and the numerous doubts regarding the suitability of using an EPDS cut-off score of 10 during pregnancy significantly weaken the methodology used in this research. It is my opinion, therefore, that the conclusions reported by the authors of the study are not sufficiently reliable, thus making this manuscript unsuitable for possible publication in BMC Pregnancy and Childbirth Thank you for the comment. We fully agree that the transcultural validity of the EPDS instrument, especially the specific cut points, cannot be taken for granted. We put a great deal of effort into identifying translated, validated versions of the instrument, as far as possible. We have carefully read and already used and discussed the validation papers to which the referee refers. We fully agree that the problem about the transcultural validity of the EPDS instrument cannot be resolved
5 by our study but would require a range of studies and would need to look into each group specifically. As this is one of the few papers attempting to address depression in pregnancy in Europe, we still consider it important to report the much higher risk of higher symptom load in several ethnic minority groups. We do not consider using different cut-off values for each ethnic group to be a good idea, since the aim was to compare the symptom load among different ethnic groups in Europe mainly with Asian and African origin, living in the same residential area in the capital of Norway. A cut-off value of 10 or greater has been found to have good psychometric properties for diagnosing depression among postnatal Norwegian women, and this cut-off has also been used in previous studies of pregnant women [15, 18, 24]. A comparable dichotomization was therefore chosen in the present study. We did, however, also perform analyses using an EPDS cut-off >12 in order to increase the specificity of the dependent variable. A higher cut-off did not change the results. In order to clarify, we have now added some more information in the discussion. 1. Humayun, A., et al., Antenatal depression and its predictors in lahore, Pakistan. Eastern Mediterranean Health Journal, 2013. 19(4): p. 327-332. 2. Ali, N.S., et al., Frequency and associated factors for anxiety and depression in pregnant women: A hospital-based cross-sectional study. The Scientific World Journal, 2012. 2012. 3. Zahidie, A., et al., Social environment and depression among pregnant women in rural areas of Sind, Pakistan. Journal of the Pakistan Medical Association, 2011. 61(12): p. 1183-1189. 4. Safi, F.N., et al., Antenatal depression: Prevalence and risk factors for depression among pregnant women in Peshawar. Journal of Medical Sciences (Peshawar), 2013. 21(4): p. 206-211. 5. Yanikkerem, E., et al., Antenatal depression: Prevalence and risk factors in a hospital based Turkish sample. Journal of the Pakistan Medical Association, 2013. 63(4): p. 472-477. 6. Wangel, A.M., et al., Mental health status in pregnancy among native and non-native Swedishspeaking women: a Bidens study. Acta Obstet Gynecol Scand, 2012. 91(12): p. 1395-401. 7. Bhugra, D., Cultural identities and cultural congruency: a new model for evaluating mental distress in immigrants. Acta Psychiatr Scand, 2005. 111(2): p. 84-93. 8. Bhugra, D. and M.A. Becker, Migration, cultural bereavement and cultural identity. World Psychiatry, 2005. 4(1): p. 18-24. 9. Eberhard-Gran, M., et al., Postnatal care: a cross-cultural and historical perspective. Arch Womens Ment Health, 2010. 13(6): p. 459-66. 10. Cox, J.L., et al., Validation of the Edinburgh Postnatal Depression Scale (EPDS) in non-postnatal women. J Affect Disord, 1996. 39(3): p. 185-9. 11. Bunevicius, A., et al., Screening for antenatal depression with the Edinburgh Depression Scale. J Psychosom Obstet Gynaecol, 2009. 30(4): p. 238-43. 12. Rubertsson, C., et al., The Swedish validation of Edinburgh Postnatal Depression Scale (EPDS) during pregnancy. Nord J Psychiatry, 2011. 65(6): p. 414-8. 13. Murray, D. and J.L. Cox, Screening for depression during pregnancy with the edinburgh depression scale (EDDS). Journal of Reproductive and Infant Psychology, 1990. 8(2): p. 99-107.
14. Eberhard-Gran, M., et al., The Edinburgh Postnatal Depression Scale: validation in a Norwegian community sample. Nord J Psychiatry, 2001. 55(2): p. 113-7. 15. Eberhard-Gran, M., et al., Depression during pregnancy and after delivery: a repeated measurement study. J Psychosom Obstet Gynaecol, 2004. 25(1): p. 15-21. 16. Garthus-Niegel, S., et al., The Wijma Delivery Expectancy/Experience Questionnaire: a factor analytic study. J Psychosom Obstet Gynaecol, 2011. 32(3): p. 160-3. 17. Nordeng, H., et al., Fear of childbirth, mental health, and medication use during pregnancy. Arch Womens Ment Health, 2012. 15(3): p. 203-9. 18. Dorheim, S.K., B. Bjorvatn, and M. Eberhard-Gran, Insomnia and depressive symptoms in late pregnancy: a population-based study. Behav Sleep Med, 2012. 10(3): p. 152-66. 19. Garthus-Niegel, S., et al., The impact of subjective birth experiences on post-traumatic stress symptoms: a longitudinal study. Arch Womens Ment Health, 2013. 16(1): p. 1-10. 20. Gjestland, K., et al., Do pregnant women follow exercise guidelines? Prevalence data among 3482 women, and prediction of low-back pain, pelvic girdle pain and depression. Br J Sports Med, 2013. 47(8): p. 515-20. 21. Dorheim, S.K., B. Bjorvatn, and M. Eberhard-Gran, Sick leave during pregnancy: a longitudinal study of rates and risk factors in a Norwegian population. Bjog, 2013. 120(5): p. 521-30. 22. Storksen, H.T., et al., Fear of childbirth; the relation to anxiety and depression. Acta Obstet Gynecol Scand, 2012. 91(2): p. 237-42. 23. Storksen, H.T., et al., The impact of previous birth experiences on maternal fear of childbirth. Acta Obstet Gynecol Scand, 2013. 92(3): p. 318-24. 24. Dorheim, S.K., B. Bjorvatn, and M. Eberhard-Gran, Can insomnia in pregnancy predict postpartum depression? A longitudinal, population-based study. PLoS One, 2014. 9(4): p. e94674. 25. Garthus-Niegel, S., et al., The influence of women's preferences and actual mode of delivery on posttraumatic stress symptoms following childbirth: a population-based, longitudinal study. BMC Pregnancy Childbirth, 2014. 14: p. 191. 6