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Cochrane Database of Systematic Reviews Editorial

A call to action to reshape evidence synthesis and use for nutrition policy

Dietary risk factors are among the leading contributors to the global burden of disease.[1] Recognizing the need for nutrition policies and interventions to tackle such risk factors, the United Nations General Assembly has proclaimed 2016 to 2025 the UN Decade of Action on Nutrition.[2] Cochrane has a strong track record of producing systematic reviews of the evidence supporting nutrition policies and interventions. For example, since 2010, Cochrane has been working with the World Health Organization (WHO) to produce systematic reviews and GRADE evidence profiles in support of WHO nutrition guidelines.[3] Nutrition reviews make up 8% (641/8486) (as of July 2015) of all active reviews published in the Cochrane Database of Systematic Reviews, featuring in the work of 47 of the 53 Cochrane Review Groups that contributed to the Cochrane Library.[4]

Nutrition policies and interventions to tackle dietary risk factors fall into two broad categories: nutrition‐specific, addressing the immediate causes of malnutrition (e.g. nutrient supplementation and fortification), and nutrition‐sensitive, addressing the underlying causes of malnutrition (e.g. agricultural or social support programmes).[5] The profile of nutrition reviews in the Cochrane Database of Systematic Reviews is dominated by nutrition‐specific interventions; 50% of nutrition reviews address nutrient supplementation alone.[4] Similar domination has been reported with the profiles of nutrition policies and guidelines recorded in the WHO e‐Library of Evidence for Nutrition Actions (eLENA), and with the implementation of nutrition actions listed in the WHO Global database on the Implementation of Nutrition Action (GINA).[6] Nutrition‐specific interventions may constitute appropriate responses for some micronutrient deficiency problems, but nutrition‐sensitive interventions may be equally, or more, effective in combating these problems, as well as being better suited to tackling dietary imbalances associated with diet‐related chronic diseases and obesity. Reviews of nutrition‐sensitive interventions can be particularly relevant and highly sought after. For example, the review by Liz Waters and her team on interventions for preventing obesity in children is one of the most downloaded reviews in the Cochrane Library and has been cited by 194 articles (as of November 2016).[7]

Although individual nutrition reviews may be providing high‐quality evidence, collectively they are likely to be skewing the body of evidence available to inform nutrition policies and interventions. A skewed body of evidence risks putting in motion a self‐perpetuating ‘evidence synthesis <‐> nutrition policy and intervention’ cycle. A relatively strong evidence base to inform nutrition‐specific policies and interventions could lead to nutrition‐specific interventions being more likely to be implemented and evaluated, compared with nutrition‐sensitive interventions, and the cycle would continue. There is a need to reshape evidence synthesis and its use in nutrition policy, particularly in relation to the following Cochrane activities:

  1. Priority‐setting: Research questions aligned with nutrition‐specific policies and interventions are receiving more attention than those aligned with nutrition‐sensitive policies and interventions.

  2. Methods: Conventional evidence synthesis approaches are based on reductionist methods, which are relatively well suited for specifying and measuring relationships between single nutrients and single physiological outcomes characteristic of nutrition‐specific interventions. Conversely, nutrition‐sensitive interventions require the development of methods for investigating complex nutrition interventions.[8, 9] Such methods need to take into account the conceptual, governance, and political challenges associated with the causes of these problems.[10, 11]

  3. Governance: The observed evidence synthesis dynamics are set against persistent concerns about potential conflicts of interest and how to manage relationships with the private sector, particularly in the context of concerns about research agenda distortion and framing effects.[12, 13, 14]

  4. Capacity: Capacity constraints in conducting nutrition systematic reviews and using evidence to inform policy are particularly apparent in low‐ and middle‐income countries.

Responding to the need to reshape evidence and its use and to ensure that nutrition polices are designed to tackle contemporary nutrition problems, a Symposium on Nutrition and Evidence for Policy and Practice was convened in Vienna, Austria, as part of the 23rd Cochrane Colloquium in 2015 (2015.colloquium.cochrane.org). The symposium explored how Cochrane might best take a proactive role in reforming evidence use in nutrition policy so as to be more relevant, transparent, and responsive to decision makers globally. Sixty people from a range of sectors and countries participated in the symposium, with presentations by members of the Cochrane Central Executive, the WHO, and national organizations, and by experts in systematic reviews and nutrition policy. The presentations led into an interactive workshop session during which symposium participants joined one of four groups to discuss an allocated question. The four overarching statements and priority actions prepared in response are documented in Table 1 and form the basis of this call to action.

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Table 1. Overarching statements and priority actions for Cochrane to reshape evidence synthesis and use for nutrition policy
original image

* e.g. causal mechanism, efficacy, effectiveness, cost, stakeholder considerations, potential for unintended consequences, sustainability, feasibility, researchability, and methodological developments

We call on Cochrane to implement the actions listed in Table 1. The recent establishment of a Cochrane Nutrition Field (nutrition.cochrane.org) provides an opportunity to progress this call to action. The Field's objectives are to:

  1. Increase the coverage, quality, and relevance of Cochrane Reviews of nutrition, through:

    • identifying priority topics and gaps in Cochrane nutrition evidence;

    • identifying and linking editors, peer reviewers, and authors with nutrition content and methodological expertise with groups conducting reviews; and

    • sourcing funding and technical resources to support review teams.

  2. Increase the impact of Cochrane nutrition reviews, through:

    • building strong relationships with other Cochrane entities and stakeholders;

    • increasing visibility of nutrition reviews in the Cochrane Library;

    • identifying Cochrane nutrition reviews that can be disseminated;

    • building capacity of researchers and decision‐makers to use evidence from reviews; and

    • promoting the use of Cochrane nutrition reviews to inform the primary research agenda and new reviews needed.

  3. Strengthen methods to conduct Cochrane nutrition reviews, through:

    • highlighting methodological strengths and limitations of existing reviews;

    • enhancing methodology; and

    • promoting activities to improve quality and reporting of primary nutrition research.

Members of Cochrane Nutrition have begun strengthening existing networks and partnerships to carry out this work. Cochrane Nutrition is based in South Africa and will seek input from within Cochrane as well as from partners outside of Cochrane. Those interested in participating in furthering this agenda are encouraged to visit nutrition.cochrane.org and get involved.

Information

DOI:
https://doi.org/10.1002/14651858.ED000118Copy DOI
Database:
  1. Cochrane Database of Systematic Reviews
Published:
  1. 21 November 2016
Copyright:
    Copyright © 2016 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.

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Authors

  • Mark Lawrence

    Public Health Nutrition, Institute for Physical Activity and Nutrition, Deakin University, Melbourne, Australia

    [email protected]

  • Celeste Naude

    Centre for Evidence‐based Health Care, Faculty of Medicine and Health Sciences, Stellenbosch University, Western Cape, South Africa

    Cochrane Nutrition

  • Rebecca Armstrong

    Jack Brockhoff Child Health & Wellbeing Program, Melbourne School of Population and Global Health, University of Melbourne, Australia

    Cochrane Public Health

  • Lisa Bero

    Medicines Use and Health Outcomes, Charles Perkins Centre and Faculty of Pharmacy, University of Sydney, Australia

    Cochrane Steering Group

  • Namukolo Covic

    Poverty, Health and Nutrition Division, International Food Policy Research Institute, Addis Ababa, Ethiopia

  • Solange Durao

    Cochrane South Africa, South Africa

    South African Medical Research Council, Cape Town, South Africa

    Cochrane Nutrition

  • Davina Ghersi

    Research Policy and Translation, National Health and Medical Research Council, Canberra, Australia

  • Geraldine Macdonald

    University of Bristol, UK

    Cochrane Developmental, Psychosocial and Learning Problems

  • Harriet MacLehose

    Cochrane Editorial Unit, Cochrane, London, UK

  • Barrie Margetts

    School of Medicine, University of Southampton, Southampton General Hospital, UK

  • David Tovey

    Cochrane, London, UK

  • Jimmy Volmink

    Centre for Evidence‐based Health Care, Faculty of Medicine and Health Sciences, Stellenbosch University, Western Cape, South Africa

    Cochrane South Africa, South Africa

    South African Medical Research Council, Cape Town, South Africa

  • Taryn Young

    Centre for Evidence‐based Health Care, Faculty of Medicine and Health Sciences, Stellenbosch University, Western Cape, South Africa

    South African Medical Research Council, Cape Town, South Africa

Declarations of interest

The authors have completed the ICMJE form for disclosure of potential conflicts of interest (form available upon request). The University of Sydney received remuneration for LB's role as Cochrane Co‐Chair. SD and CN are Directors of Cochrane Nutrition. The authors declare no additional conflicts.

Acknowledgements

This call to action is dedicated to Liz Waters, who was the driver of this reform agenda at Cochrane. Her leadership in, and passion for, evidence‐informed public health practice, and her generous support for colleagues are sadly missed.

Provenance and peer review

This editorial was commissioned and was not externally peer reviewed.

References

  1. Forouzanfar MH, Alexander L, Anderson HR, Bachman VF, Biryukov S, Brauer M, et al. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet 2015;365:2287–323. doi.org/10.1016/S0140‐6736(15)00128‐2
  2. World Health Organization. General Assembly proclaims the Decade of Action on Nutrition. www.who.int/nutrition/GA_decade_action (accessed 29 June 2016)
  3. Tovey D. The role of The Cochrane Collaboration in support of the WHO nutrition guidelines. Advances in Nutrition2014;5(1):35–9. doi.org/10.3945/an.113.004895
  4. Naude C, Durao S, Harper A, Volmink J. Scope and quality of Cochrane Reviews of nutrition‐related interventions (2016). Data on file.
  5. Unicef. Multi‐sectoral approaches to nutrition: nutrition‐specific and nutrition‐sensitive interventions to accelerate progress. www.unicef.org/eapro/Brief_Nutrition_Overview.pdf (accessed 17 June 2016)
  6. Lawrence M, Wingrove K, Naude C, Durao S. Evidence synthesis and translation for nutrition interventions to combat micronutrient deficiencies with particular focus on food fortification. Nutrients2016;8(9):555. doi.org/10.3390/nu8090555
  7. Waters E, de Silva‐Sanigorski A, Burford BJ, Brown T, Campbell KJ, Gao Y, et al. Interventions for preventing obesity in children. Cochrane Database of Systematic Reviews2011;(12):CD001871. doi.org/10.1002/14651858.CD001871.pub3
  8. Fardet A, Rock E. Toward a new philosophy of preventive nutrition: from a reductionist to a holistic paradigm to improve nutritional recommendations. Advances in Nutrition2014;5(4):430–46. doi.org/10.3945/an.114.006122
  9. Pelletier DL, Porter CM, Aarons GA, Wuehler SE, Neufeld LM. Expanding the frontiers of population nutrition research: new questions, new methods, and new approaches. Advances in Nutrition2013;4(1):92–114. doi.org/10.3945/an.112.003160
  10. Truswell A. Some problems with Cochrane reviews of diet and chronic disease. European Journal of Clinical Nutrition2005;59( suppl 1):S150–4. doi.org/10.1038/sj.ejcn.1602189
  11. Lodge M, Becker L, Van Binsbergen J, Van Weel C, Rosser W. Organisation of a proposed Cochrane Diet and Nutrition Field. European Journal of Clinical Nutrition2005;59( suppl 1):S162–6. doi.org/10.1038/sj.ejcn.1602191
  12. Marks JH. Toward a systemic ethics of public‐private partnerships related to food and health. Kennedy Institute of Ethics Journal2014;24(3):267–99. doi.org/10.1353/ken.2014.0022
  13. Moodie R, Stuckler D, Monteiro C, Sheron N, Neal B, Thamarangsi T, et al. Profits and pandemics: prevention of harmful effects of tobacco, alcohol, and ultra‐processed food and drink industries. Lancet2013;381(9867):670–9. doi.org/10.1016/S0140‐6736(12)62089‐3
  14. Stuckler D, Basu S, McKee M. Global health philanthropy and institutional relationships: how should conflicts of interest be addressed?PLOS Medicine2011;8(4):e1001020. doi.org/10.1371/journal.pmed.1001020
Table 1. Overarching statements and priority actions for Cochrane to reshape evidence synthesis and use for nutrition policy
original image

* e.g. causal mechanism, efficacy, effectiveness, cost, stakeholder considerations, potential for unintended consequences, sustainability, feasibility, researchability, and methodological developments

Figures and Tables -
Table 1. Overarching statements and priority actions for Cochrane to reshape evidence synthesis and use for nutrition policy