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The long gestation of screening programmes for perinatal depressive disorders
Journal of Psychosomatic Research 77 (2014) 242–243
Contents lists available at ScienceDirect
Journal of Psychosomatic Research
Letter to the Editor The long gestation of screening programmes for perinatal depressive disorders The recent correspondence by Thombs and colleagues [1,2] and by Chaudron and Wisner [3] encapsulates the central dilemmas in the debate around the use of depression screening tools in the perinatal period. As a strategy, the fundamental attraction of screening for perinatal depression is the potential to increase identification and treatment rates and thereby reduce morbidity. Demonstrating such clinical effectiveness is central to the decision to implement population screening. Yet, despite the consensus that early treatment of depressive illness in the perinatal period is desirable to maximise recovery and to lessen the impact on infants, quality evidence for the clinical effectiveness of screening programmes is slow to appear. At the end of the last decade, there were essentially no published controlled trials of the effects (potential benefits and potential harms) of perinatal screening on depression-associated morbidity of even moderate quality. This has led to an extended period where we have been unable to make an informed judgement either for or against the benefits of screening — because there is insufficient evidence to weigh. The latest systematic review by Thombs et al. [1] tells us that, in hard-nosed evidence-based terms, the situation remains much unchanged since the Health Technology Assessment by Hewitt et al. [4] in 2009 and the comparative effectiveness review by the Agency for Healthcare Research and Quality (AHRQ) in 2013 [5]. Though a handful of other relevant randomised controlled trials (RCTs) and cluster trials have emerged and have shown positive results on women's outcomes, Thombs et al. had to exclude them from their review on methodological grounds and so the stack of evidence for effectiveness which we can reliably call “good quality” remains as thin as ever. Even including the material excluded by the latest review, we are left with the conclusions of the AHRQ's 2013 review basically unchanged — at best we have lowto-moderate strength of evidence for the effectiveness of programmes that combine screening with some enhancements to management. This continued lack of evidence for or against screening has had the somewhat paradoxical effect, as pointed out by Chaudron and Wisner [3], that various international institutions currently advise against formal screening tools while urging perinatal clinicians to “be alert” to the “signs” of depression or to make an assessment of “risk factors”. In other words, a heterogeneous assemblage of health professionals with widely divergent skills and experience are themselves to operate as informal, un-validated “screening tools”. To my knowledge there is no evidence from RCTs that can inform us of the balance of potential harms and benefits resulting from urging such a policy of non-systematic identification strategies for perinatal depression. This brings us back full circle to the question of whether deploying an established, formal screening tool, whose limitations, psychometric validity and test properties are well-known, might not be a safer bet in the meantime than relying on non-systematic ‘usual care’ methods.
http://dx.doi.org/10.1016/j.jpsychores.2014.06.017 0022-3999/© 2014 Elsevier Inc. All rights reserved.
As we wait for more evidence to emerge, it is worth remembering that all the available studies that come close to providing quality evidence in favour of the effectiveness of formal screening have involved screening tools being integrated as part of a well-resourced and coordinated overall programme with clear aims. We know that introducing a depression screening instrument in isolation, even in high income countries with relatively abundant health system resources, is likely to do zero good in the absence of accompanying system changes to support and optimise the screening effort [6]. Probably the most important one to stipulate is that every ‘positive’ screening result should be followed by a diagnostic procedure and only on the basis of a formal diagnosis should treatment be commenced. The aims here are minimising potential harms (such as stigma and inappropriate medical intervention) and maximising cost-effectiveness [7]. Perhaps the most important message of Thombs et al.'s review (like Hewitt et al. before them) is the central difficulty of isolating the clinical effect of screening itself from other enhancements to care that often accompany screening in the intervention groups of RCTs but not the control groups. In the context of an RCT, not only do sufficient, effective management resources need to be available when depression is identified, they need to be equally available whether depression is identified by the screening intervention or by non-systematic processes in the ‘usual care’ control groups. In delineating the central shortcomings of the available evidence, Thombs et al. have also provided a template for how a good quality RCT of perinatal depression screening should be configured to deliver some long overdue answers to questions around effectiveness. We should look forward to seeing such well-configured RCTs emerge more quickly and urgently now because, as Chaudron and Wisner point out, most of the other prerequisites for implementing population level perinatal screening are already supported by the evidence and awaiting the last pieces of the puzzle to fall into place. Lastly, even if a dozen high quality RCTs were published tomorrow, it may well be a mistake to expect that there will ever be a single unqualified answer to whether perinatal depression screening is effective or not. It may prove possible to reduce morbidity in some health jurisdictions via depression screening more easily than in others. Outside of RCTs, the utility of screening programmes in the ‘real world’ will continue to depend upon the setting, the population, the health resources available, system changes that maximise the impact of screening efforts and the quality of the programmes' aims, design and implementation. While the researchers debate and weigh the available evidence, the continuing reality in current practice is that most women suffering depression in the perinatal period go unidentified and receive no effective care at all [8]. The recent correspondence in this journal [1–3] should therefore serve as a catalyst for international collaborative efforts towards the systematic testing of integrated screening programmes in well-designed RCTs as a matter of urgency.
Letter to the Editor
Acknowledgments The author would like to thank to Professor Jeannette Milgrom for the useful discussions.
243
[6] Gilbody S, House A, Sheldon T. Screening and case finding instruments for depression. Cochrane Database Syst Rev 2009;4 [Art. No: CD002792]. [7] Paulden M, Palmer S, Hewitt C, Gilbody S. Screening for postnatal depression in primary care: cost effectiveness analysis. BMJ (Clin Res ed) 2009;339:b5203. [8] Bowen A, Bowen R, Butt P. Patterns of depression and treatment in pregnant and postpartum women. Can J Psychiatry 2012;57:161–7.
References [1] Thombs BD, Arthurs E, Coronado-Montoya S, Roseman M, Delisle VC, Leavens A. Depression screening and patient outcomes in pregnancy or postpartum: a systematic review. J Psychosom Res 2014;76:433–46. [2] Thombs BD, Stewart DE. Depression screening in pregnancy and postpartum: who needs evidence? J Psychosom Res 2014;76:492–3. [3] Chaudron LH, Wisner K. Perinatal depression screening: let's not throw the baby out with the bathwater! J Psychosom Res 2014;76:489–91. [4] Hewitt C, Gilbody S, Brealey S, Paulden M, Palmer S, Mann R, et al. Methods to identify postnatal depression in primary care: an integrated evidence synthesis and value of information analysis. Health Technol Assess 2009;13:1–145 [147–230]. [5] Myers E, Aubuchon-Endsley N, Bastian LA, Gierisch JM, Kemper AR, Swamy GK, et al. Efficacy and safety of screening for postpartum depression. Comparative effectiveness review, 106. Rockville, MD: Agency for Healthcare Research and Quality; 2013.
Alan W. Gemmill Parent–Infant Research Institute, Department of Clinical & Health Psychology, Heidelberg Repatriation Hospital, Austin Health, Heidelberg West, Vic, Australia Tel.: +61 3 9496 4468; fax: +61 3 9496 4148. E-mail address: [email protected].
3 June 2014
Contents lists available at ScienceDirect
Journal of Psychosomatic Research
Letter to the Editor The long gestation of screening programmes for perinatal depressive disorders The recent correspondence by Thombs and colleagues [1,2] and by Chaudron and Wisner [3] encapsulates the central dilemmas in the debate around the use of depression screening tools in the perinatal period. As a strategy, the fundamental attraction of screening for perinatal depression is the potential to increase identification and treatment rates and thereby reduce morbidity. Demonstrating such clinical effectiveness is central to the decision to implement population screening. Yet, despite the consensus that early treatment of depressive illness in the perinatal period is desirable to maximise recovery and to lessen the impact on infants, quality evidence for the clinical effectiveness of screening programmes is slow to appear. At the end of the last decade, there were essentially no published controlled trials of the effects (potential benefits and potential harms) of perinatal screening on depression-associated morbidity of even moderate quality. This has led to an extended period where we have been unable to make an informed judgement either for or against the benefits of screening — because there is insufficient evidence to weigh. The latest systematic review by Thombs et al. [1] tells us that, in hard-nosed evidence-based terms, the situation remains much unchanged since the Health Technology Assessment by Hewitt et al. [4] in 2009 and the comparative effectiveness review by the Agency for Healthcare Research and Quality (AHRQ) in 2013 [5]. Though a handful of other relevant randomised controlled trials (RCTs) and cluster trials have emerged and have shown positive results on women's outcomes, Thombs et al. had to exclude them from their review on methodological grounds and so the stack of evidence for effectiveness which we can reliably call “good quality” remains as thin as ever. Even including the material excluded by the latest review, we are left with the conclusions of the AHRQ's 2013 review basically unchanged — at best we have lowto-moderate strength of evidence for the effectiveness of programmes that combine screening with some enhancements to management. This continued lack of evidence for or against screening has had the somewhat paradoxical effect, as pointed out by Chaudron and Wisner [3], that various international institutions currently advise against formal screening tools while urging perinatal clinicians to “be alert” to the “signs” of depression or to make an assessment of “risk factors”. In other words, a heterogeneous assemblage of health professionals with widely divergent skills and experience are themselves to operate as informal, un-validated “screening tools”. To my knowledge there is no evidence from RCTs that can inform us of the balance of potential harms and benefits resulting from urging such a policy of non-systematic identification strategies for perinatal depression. This brings us back full circle to the question of whether deploying an established, formal screening tool, whose limitations, psychometric validity and test properties are well-known, might not be a safer bet in the meantime than relying on non-systematic ‘usual care’ methods.
http://dx.doi.org/10.1016/j.jpsychores.2014.06.017 0022-3999/© 2014 Elsevier Inc. All rights reserved.
As we wait for more evidence to emerge, it is worth remembering that all the available studies that come close to providing quality evidence in favour of the effectiveness of formal screening have involved screening tools being integrated as part of a well-resourced and coordinated overall programme with clear aims. We know that introducing a depression screening instrument in isolation, even in high income countries with relatively abundant health system resources, is likely to do zero good in the absence of accompanying system changes to support and optimise the screening effort [6]. Probably the most important one to stipulate is that every ‘positive’ screening result should be followed by a diagnostic procedure and only on the basis of a formal diagnosis should treatment be commenced. The aims here are minimising potential harms (such as stigma and inappropriate medical intervention) and maximising cost-effectiveness [7]. Perhaps the most important message of Thombs et al.'s review (like Hewitt et al. before them) is the central difficulty of isolating the clinical effect of screening itself from other enhancements to care that often accompany screening in the intervention groups of RCTs but not the control groups. In the context of an RCT, not only do sufficient, effective management resources need to be available when depression is identified, they need to be equally available whether depression is identified by the screening intervention or by non-systematic processes in the ‘usual care’ control groups. In delineating the central shortcomings of the available evidence, Thombs et al. have also provided a template for how a good quality RCT of perinatal depression screening should be configured to deliver some long overdue answers to questions around effectiveness. We should look forward to seeing such well-configured RCTs emerge more quickly and urgently now because, as Chaudron and Wisner point out, most of the other prerequisites for implementing population level perinatal screening are already supported by the evidence and awaiting the last pieces of the puzzle to fall into place. Lastly, even if a dozen high quality RCTs were published tomorrow, it may well be a mistake to expect that there will ever be a single unqualified answer to whether perinatal depression screening is effective or not. It may prove possible to reduce morbidity in some health jurisdictions via depression screening more easily than in others. Outside of RCTs, the utility of screening programmes in the ‘real world’ will continue to depend upon the setting, the population, the health resources available, system changes that maximise the impact of screening efforts and the quality of the programmes' aims, design and implementation. While the researchers debate and weigh the available evidence, the continuing reality in current practice is that most women suffering depression in the perinatal period go unidentified and receive no effective care at all [8]. The recent correspondence in this journal [1–3] should therefore serve as a catalyst for international collaborative efforts towards the systematic testing of integrated screening programmes in well-designed RCTs as a matter of urgency.
Letter to the Editor
Acknowledgments The author would like to thank to Professor Jeannette Milgrom for the useful discussions.
243
[6] Gilbody S, House A, Sheldon T. Screening and case finding instruments for depression. Cochrane Database Syst Rev 2009;4 [Art. No: CD002792]. [7] Paulden M, Palmer S, Hewitt C, Gilbody S. Screening for postnatal depression in primary care: cost effectiveness analysis. BMJ (Clin Res ed) 2009;339:b5203. [8] Bowen A, Bowen R, Butt P. Patterns of depression and treatment in pregnant and postpartum women. Can J Psychiatry 2012;57:161–7.
References [1] Thombs BD, Arthurs E, Coronado-Montoya S, Roseman M, Delisle VC, Leavens A. Depression screening and patient outcomes in pregnancy or postpartum: a systematic review. J Psychosom Res 2014;76:433–46. [2] Thombs BD, Stewart DE. Depression screening in pregnancy and postpartum: who needs evidence? J Psychosom Res 2014;76:492–3. [3] Chaudron LH, Wisner K. Perinatal depression screening: let's not throw the baby out with the bathwater! J Psychosom Res 2014;76:489–91. [4] Hewitt C, Gilbody S, Brealey S, Paulden M, Palmer S, Mann R, et al. Methods to identify postnatal depression in primary care: an integrated evidence synthesis and value of information analysis. Health Technol Assess 2009;13:1–145 [147–230]. [5] Myers E, Aubuchon-Endsley N, Bastian LA, Gierisch JM, Kemper AR, Swamy GK, et al. Efficacy and safety of screening for postpartum depression. Comparative effectiveness review, 106. Rockville, MD: Agency for Healthcare Research and Quality; 2013.
Alan W. Gemmill Parent–Infant Research Institute, Department of Clinical & Health Psychology, Heidelberg Repatriation Hospital, Austin Health, Heidelberg West, Vic, Australia Tel.: +61 3 9496 4468; fax: +61 3 9496 4148. E-mail address: [email protected].
3 June 2014