Identifying topics for future Cochrane Public Health reviews

Cochrane systematic reviews summarize evidence to support decision making about public health policy, practice and individual health behaviour.¹ The potential benefits of systematic reviews may be maximized when they address priority public health issues. This may include health risk factors of conditions of considerable burden of disease.

Cochrane is an international non-profit organization that publishes systematic reviews of the effects of health interventions, diagnostic test accuracy and prognosis questions. The conduct and publication of Cochrane reviews are supported by 53 Cochrane Review Groups, each of which supports the development of reviews in specific areas of health. Reviews of interventions targeting the social and economic determinants of health and chronic disease prevention fall within the scope of Cochrane Public Health (CPH) (see Box 1).

Box. 1 .

Scope of cochrane public health.²

Historically, the selection of research questions for Cochrane reviews has been driven by author teams based on their individual areas of interest or capacity. Such an approach has the potential to lead to a disconnect between the reviews undertaken and topics of importance to policy and health decision makers. To minimize this risk and help ensure Cochrane reviews meet the needs of end users, Cochrane has developed guidance on the prioritization of systematic review topics.³ The guidance document outlines recommended processes for undertaking priority setting, including ways in which priorities can be elicited via group governance arrangements and stakeholder engagement, and advises on documentation, dissemination of priorities, and how often these processes should be undertaken to maintain currency.³

In line with this Cochrane guidance, in 2019 and 2020, CPH undertook a review prioritization process to:

1. identify relevant current and potential stakeholders of CPH,

2. determine the priority review topics of identified CPH stakeholders,

3. collate and assess stakeholder-nominated review topics in terms of relevance to CPH scope,² need and potential impact,

4. determine a list of key review topics for CPH for the next five-year period (2021–2025), and

5. identify any stakeholders with an interest in direct involvement in the conduct of specific CPH reviews.

Identification of key CPH stakeholders

A stakeholder analysis was conducted to identify CPH stakeholder organizations working in public health policy or practice including potential funders of reviews; policy and guideline developers; organizations working in low- and middle-income countries; or public health organizations with regional or global reach. Stakeholder organizations were initially identified through CPH’s existing networks and targeted web searches of key organizations and agencies. Key contacts for the stakeholder organizations were initially identified from web searches. A list of 87 current and potential stakeholders of CPH was developed.

From December 2019 until April 2020, a survey of CPH stakeholders was conducted using REDCap, a web-based survey platform.⁴ Multiple methods and strategies were used to promote the survey and encourage completion. Initially, the survey link was emailed (using public domain email addresses) to the key contact of identified stakeholder organizations. Reminder emails and telephone calls were made to those stakeholders who had not responded within 1–2 months. A snowballing approach was taken, whereby invited participants were encouraged to forward the survey to their own networks. The survey was also publicly advertised on the CPH website and the Cochrane website (where current priority setting projects are routinely promoted).⁵ A ‘Tweet’ was posted from the CPH Twitter account tagging key members of the CPH editorial team, prompting them to share the Tweet with their broader networks and encourage participation. Finally, CPH editors, an international panel of senior public health researchers working in a variety of countries and fields, and contacts at Cochrane Geographic Groups (centres or hubs for Cochrane and evidence synthesis research in specific countries around the world)⁶ were invited by email to distribute the survey link to stakeholders in their regions.

Capturing the priorities of CPH stakeholders

The review prioritization survey asked participants to identify up to 10 priority systematic review topics addressing the effects of one or more interventions. For each priority topic or problem, participants were asked to consider: population group/s, intervention/s and setting/s of interest. Participants were also asked: if they were aware of any existing reviews on their suggested topic/s, and if so, why the existing reviews did not meet their need; and if there was a deadline or reason for a review on a suggested topic (e.g. planned guideline update). Finally, participants were asked if they would be interested in contributing to a review on their suggested topic/s, and how they would like to participate (i.e. in determining the review questions and outcomes, reviewing drafts of the review/s for appropriate language, interpretation and policy relevance, disseminating review findings, or funding a review). A copy of the survey can be found in Supplementary File A.

A total of 36 surveys were completed including 24 from stakeholder that were not on the initial list of identified stakeholders. The majority of completed surveys were from the UK (n = 11) and Australia (n = 7), with additional responses from Austria (n = 5), Germany (n = 3), Colombia (n = 2), Hong Kong (n = 1), Hungary (n = 1), Sweden (n = 1), Bosnia and Herzegovina (n = 1), and Canada (n = 1). Two survey responses were received from international agencies. There was one response from an unknown organization or location. The majority of surveys were completed by stakeholders located within high-income countries (n = 31). Fifteen participants indicated that their organizations would like to be involved in CPH reviews that were a priority to them, with 14 indicating they would be interested in determining the scope of the review; one indicating they would be interested in commissioning or funding reviews; 11 indicating they would be interested in reviewing drafts of reviews; and 10 indicated that they were interested in disseminating review findings.

Grouping and assessing the priorities of CPH stakeholders

Two authors (CB and ED) independently assessed and grouped the review topics received from the survey, with similar review topics collapsed into one topic area where appropriate. Two authors then independently assessed the suggested review topic areas against the following criteria. Disagreements were resolved via consensus, or a third author (MK) if required.

1. Relevance:

   1. Did the topics fall within CPH scope (see Box 1)?²

2. Need:

   1. Was the suggested review topic already addressed by an existing published systematic review (Cochrane Review or other)?

   2. If so, was the review published recently enough to be considered current (<5 years ago)?

3. Potential global impact:

   1. Global Burden of Disease: Was the topic relevant to the top 20 non-communicable disease (NCD) risk factors (based on DALYs)?^7,8 and/or

   2. World Health Organization (WHO) NCD Global Monitoring Framework: Was the topic relevant to the current 10 WHO NCD Global Monitoring Framework risk factor indicators?⁹

Based on the assessment of the proposed topics against these three criteria, a list of priority review topics for CPH was created based on those topics that satisfied each of the three criteria.

CPH priority topics areas for 2021–2025

The 36 survey participants suggested 69 review topics in total (range: 1–9 topics each) that were grouped into 13 topic areas. These topics were assessed against the abovementioned criteria and six were removed based on relevance, zero based on need and four were removed based on potential global impact. The responses received by stakeholders generally did not provide enough details in regards to population groups, interventions and settings to identify specific review questions.

Non-communicable disease prevention was identified as the broad priority area for CPH for the 2021–2025 period. Specifically, first-order priorities are:

• Dietary risks (N = 6 stakeholder respondents)—including the effectiveness of policy, regulation and taxation interventions on food production and supply (agriculture, manufacturing and retail), and the impact of such interventions on health equity.

• Obesity/high body mass index (N = 3 stakeholder respondents)—including the effectiveness of interventions in health settings and at the policy level in reducing population rates of obesity in adults and children.

• Physical activity (N = 5 stakeholder respondents)—including the effectiveness of interventions at the policy level and those that involve urban development planning and public transport strategies for increasing physical activity among adults and children.

Additionally, the following topics were identified as second-order priorities based on need and relevance:

• Health inequities—including the effectiveness of social policy on improving social determinants of health (e.g. poverty, homelessness) and public health outcomes; effectiveness of public health interventions for migrant populations.

• Mental health—including the effectiveness of interventions to encourage social connection and reduce loneliness on public health outcomes.

• Environmental hazards—including the effectiveness of regulatory interventions in reducing risk of domestic hazards.

• Knowledge translation—including the effectiveness of strategies to improve the translation of public health interventions into policy and practice, including for benefit of vulnerable groups.

The importance of the first-order CPH review priorities

Globally, in 2019, dietary risks, high body mass index and low physical activity were responsible for 188 million, 160 million and 16 million DALYs and 8 million, 5 million and 832 000 deaths among adults aged 25 and older.⁸ Recognizing this burden, the World Health Organization has established global targets and indicators for these risk factors.⁹ For dietary risk, a target of 30% relative reduction in mean population intake of salt/sodium has been set and indicators related to energy intake from saturated fatty acids and daily consumption of fruit and vegetables established. Halting the rise of obesity has been also been set as a target and indicators related to overweight and obesity in adolescents and persons aged 18+ years established. For physical activity, a target of 10% relative reduction in the prevalence of insufficient physical activity has been set and indicators for insufficient physical activity amongst adolescents and persons aged 18+ years have been established. Systematic reviews of effective public heath interventions are crucial for informing public health strategy and investment in address these global priorities and achieve these targets.

Limitations

We recognize that not all relevant stakeholders have been able to contribute to this process, and subsequently the listed priorities may not reflect the priorities of all of CPH’s global policy and practice stakeholders. Therefore, the priority list derived from this time-limited process will not negate CPH considering other important public health topics that emerge over time. It is also likely that there may be some overlap with the scope of other Cochrane review groups and some topics may be transferred to other groups depending on capacity.

Call to action

CPH calls for appropriately experienced author teams to develop specific review questions that align with these stakeholder-driven priority areas and submit review proposals to CPH for consideration (see https://ph.cochrane.org/review-authors for further information on process). Author teams are encouraged to continue to involve stakeholders in the process of refining, producing and disseminating their reviews in order to ensure that the questions asked, and outcomes measured, are relevant to stakeholder needs and maximize the impact of review findings.¹⁰ CPH will put author teams in contact with stakeholder organizations that expressed interest in participating in the production and dissemination of priority reviews. CPH provides ongoing support to author teams including methodological guidance and assistance to embed knowledge translation planning throughout the review process and develop translation products to improve the accessibility of findings for end-user stakeholders. Reviews currently in progress are listed on the CPH website (https://ph.cochrane.org/).

Funding

This work is supported by a National Health and Medical Research Council grant provided to Cochrane Public Health to support the production of systematic reviews.

Melanie Kingsland

Courtney Barnes

Emma Doherty

Sam McCrabb

Meghan Finch

Miranda Cumpston

Rebecca Armstrong

Lorainne Tudor Car

Jodie Doyle

Luke Wolfenden