Our activities
Survey of existing Campbell Coordinating Groups and Cochrane Collaborative Review Groups
We are conducting a survey to determine which Campbell Coordinating groups, and Cochrane Collaborative Review Groups, report outcomes by socioeconomic position in their reviews, (and how they do this), and why the others do not. We will also identify appropriate criteria for including evaluation of effectiveness by socioeconomic position in reviews. An assessment of the needs of Campbell and Cochrane Collaborative Review Groups from an equity perspective is also being conducted. This will help ensure that the Field's work is driven by the demands of Collaborative Review Groups.
Development of database of useful applications and organizations
We are developing a database of useful equity-applications of Campbell and Cochrane reviews with a clinical focus, and organizations to which reviews may make significant contributions. Examples of this may include Health Impact Assessment and cost-equity analyses. We hope to provide a link between these organizations and the Campbell and Cochrane Collaborations.
Development and assessment of new methodologies
We are working with Collaborative Review and Methods Groups to address the methodological issues outlined later in the document. We have been working on reviewers' checklists; these will be used by review authors who are considering equity and equity implications in their reviews. We will be testing the checklists with Collaborative Review and Methods Groups to evaluate their applicability and efficacy.
Search strategy
Based on the included studies from three published reviews of interventions to decrease inequalities in health (Arblaster 1996, Gepkens and Gunning Schepers 1996, Machenbach 2003), we have begun to develop a search strategy. We will evaluate this search strategy to determine its sensitivity and specificity.
Guideline development
We are reviewing the Campbell and Cochrane handbooks and methods guidance documents to identify changes that would need to be made in order to facilitate reviews on clinical interventions to reduce socioeconomic inequities in health. This will include recommendations on formulation of the question, collecting data, interpreting evidence across factors such as socioeconomic position and gender, and discussing the implications of research findings for clinicians, consumers and policy-makers.
Trial registry
We are developing a Specialised Register of studies related to equity, particularly with a clinical focus. We are collaborating with the EPPI-Centre (Evidence for Policy and Practice Information and Coordinating Centre, http://eppi.ioe.ac.uk/cms/) - who are responsible for maintaining the studies register of the Health Promotion and Public Health Field (http://eppi.ioe.ac.uk/webdatabases/Intro.aspx?ID=5) - to share experiences and avoid duplication in efforts. We propose developing our specialized register with the following:
- Randomised controlled trials (RCTs), defined as trials in which the participants (or other units) were definitely assigned prospectively to one or two (or more) alternative forms of health care using a process of random allocation (e.g. random number generation, coin flips).
- Controlled clinical trials (CCTs), defined as trials in which participants (or other units) were either:
o definitely assigned prospectively to one or two (or more) alternative forms of health care using a quasi-random allocation method (e.g. alternation, date of birth, patient identifier), or
o possibly assigned prospectively to one or two (or more) alternative forms of health care using a process of random or quasi-random allocation.
These will be forwarded to CENTRAL. Once the register is well-established with RCTs and CCTs, we will look at incorporating other observational study designs such as controlled before-after and interrupted time series studies.
Equity expertise in Campbell Coordinating Groups and Cochrane Collaborative Review Groups
We are working to increase the representation of equity experts in Campbell Coordinating groups and Cochrane Collaborative Review Groups as well as increase the awareness of equity issues in these groups. By promoting and supporting the consideration of equity issues within the research synthesis community and the wider research community, we hope to encourage involvement in the work of both collaborations. This will help increase capacity to produce high quality equity reviews, in ways that are appropriate, valid, reliable and unbiased.
The Cochrane Health Equity Field and Campbell Equity Methods Group will provide training and support to Collaborative Review Groups and to individual researchers as part of the overall program of methodological training provided by the Campbell and Cochrane collaboration. It is likely, that at least initially, this may involve short workshops or seminars as part of Campbell and Cochrane meetings.
We will also provide a forum for discussion around the role of equity in systematic reviews and the development of the relevant methods. A listserv will be set up as a medium for these discussions. We will also develop a website, annual newsletter, and conduct annual meetings at Campbell and Cochrane Colloquia.
When appropriate, members of the Health Equity Field may also support the production of equity reviews. This involvement may range from providing advice on the protocol, to assessing the quality of the review, to taking a more active role in the review process.
We will also offer to help Cochrane and Campbell Collaborative Review Groups to identify peer referees with equity expertise for relevant reviews.
Accessibility of Campbell and Cochrane reviews
We will promote the accessibility of Campbell and Cochrane reviews, particularly reviews reporting information on equity-relevant considerations or presenting data stratified by socioeconomic status. This will be achieved primarily through the groups listed previously, under the Links and Liaisons heading, and through the promotion of the Collaborations at international meetings and conferences to encourage the use of Campbell and Cochrane reviews as a source of evidence. We will also encourage and promote new reviews on health equity as well as consideration of equity in existing or ongoing reviews, where appropriate. We also hope to make presentations at relevant conferences and meetings.
Funding opportunities
We will assist Collaborative Review Groups in their efforts to obtain funding, whether this is through providing letters of support or identifying funding opportunities. We will also look for opportunities to support Cochrane and Campbell reviews at equity relevant international conferences and through our contacts with external individuals and organisations.
Priority-setting for low- and middle-income countries
A collaborative bid was successfully submitted for the Cochrane Collaboration Prioritization Projects grant in 2007; this was a joint effort by the Cochrane Health Equity Field, Cochrane Developing Countries Network, Cochrane Health Promotion and Public Health Field, and Cochrane Effective Practice and Organization of Care Oslo Satellite on LMIC.
We received funding for our project entitled “Prioritizing Cochrane review topics to reduce the know-do gap in low and middle income countries”. For this project, we will:
1) Identify what priority-setting approaches are underway by Cochrane entities already and whether/how these can inform priorities for systematic reviews of relevance to LMIC
2) Explore different methods of identifying priorities for systematic reviews for specific audiences, recognizing that priorities may be different (eg for policy-makers, for practitioners). We might convene small working groups of practitioners to identify priorities for systematic reviews at a national or regional level
3) Map existing systematic reviews to identified priorities to identify gaps/needs for new systematic reviews, as well as showing whether the Cochrane Database of Systematic Reviews already answers high-priority questions relevant to LMIC
Empirical research
We plan to conduct empirical methodological research on what equity data is needed in Campbell and Cochrane reviews and how to apply reviews for equity-oriented policy, but particularly for clinical decisions. We believe that advice given should be based on empirical research rather than opinion and so aim to further the methods development in this field.
Methodologic issues of interest are summarized below:
1.0 Methodological and related research, including:
1.1 Health impact assessment (HIA)
1.2 Equity-effectiveness
1.3 Knowledge translation strategies that work in the poor
1.4 Applicability of Campbell and Cochrane reviews to equity-relevant clinical
guidelines
2.0 Use of equity implications on effectiveness to inform policy development
3.0 Cost-equity
4.0 Differences in risk and response in disadvantaged groups
5.0 Measurement of equity factors in systematic reviews, including:
5.1 Validated definition of equity factors, and their measurement in reviews
5.2 Assessment of social gradients in health as an outcome in systematic reviews
5.3 Assessing the impact of social determinants of health on effectiveness
5.4 Development of outcome measures to assess equity of care
6.0 Modelling (statistical) techniques
7.0 Finding controlled studies on health equity
8.0 Statistical issues around socioeconomic subgroup analysis
1.0 Methodological and related research
The following applications are possible opportunities for the application of Campbell and Cochrane reviews. As noted, however, methods work is required to optimize their utilization (Kelly 2006).
1.1 Health impact assessment
There is a need to identify the impact of policy strategies on health inequalities within a population. Health Impact Assessment (HIA) has been defined as "a combination of procedures, methods and tools by which a policy, program or project may be judged as to its potential effects on the health of a population, and the distribution of those effects within the population" (WHO 1999). If given an equity focus, HIA could help raise awareness of the equity implications of policies and interventions (Mackenbach 2003). In the 1998 UK independent Inquiry into Inequality and Health, (Acheson Report 1998), the first recommendation was that "as part of health impact assessment, all policies to have a direct or indirect effect on health should be evaluated in terms of their impact on health inequalities, and should be formulated in such a way that by favouring the less well off they will, wherever possible, reduce such inequalities".
Campbell and Cochrane have the potential to be a major tool in equity focused HIA, by providing evidence with which to inform, develop and appraise policies (Williams 2003). Methods to facilitate the application of reviews in the HIA process however need to be developed, particularly as use of evidence in policy formulation is still widely controversial (Williams 2003). This is largely due to a belief that empirical evidence often fails to take into account the many factors at play in a community, and therefore fails to give accurate estimates of the effectiveness of an intervention.
Next steps: We propose to design and test methods for applying Campbell and Cochrane evidence to policy evaluation processes, in particular how to use reviews in HIA and what additional information is required in reviews to be helpful for HIA. We will draw on existing work in the area, such as Aldrich 2005 and Mindell 2004, for background material.
1.2 Equity effectiveness
A suggested equity-oriented application of Campbell and Cochrane reviews is as a "best source" of efficacy data, which can be used as an anchor for the calculation of the hypothetical equity-effectiveness of interventions. The calculation of equity-effectiveness, involves the application of an equity lens to four factors that are known to negatively impact the efficacy of an intervention or policy in the community: (i) awareness/access/coverage; (ii) screening/diagnosis/targeting; (iii) provider compliance; and (iv) consumer adherence (Tugwell, 2006). One example of a hypothetical community effectiveness described in this paper calculates the community effectiveness of treated bednets to decrease cases of malaria. This calculation required the absolute and relative risks for malaria in disadvantaged groups, compliance data from included trials, as well as information relating to the delivery of the intervention (coverage/access etc) in disadvantaged groups. Little of this information is routinely published in Campbell or Cochrane reviews.
Next steps: We will explore the appropriate description of this contextual information in Cochrane and Campbell reviews, including consumer adherence, awareness and coverage, provider compliance and the processes of implementation.
1.3 Knowledge translation strategies that work in the poor
The World Bank Health, Nutrition and Population program, Reaching the Poor, has developed and funded several case studies on interventions that are targeted to the poor. This program has been developed with the commitment of the World Bank to "taking action to reduce inequalities". There is tremendous potential for synergy between the Campbell and Cochrane Collaborations and this World Bank initiative. However, there is currently a lack of reviews on knowledge translation and implementation interventions that are designed to reach the poor. Furthermore, those reviews that deal with relevant interventions do not often discuss the different methods of implementation and their contribution to effectiveness. These methods of implementation such as social marketing, vouchers and advertising play a large role in achieving community uptake of programs, or interventions (e.g. bednets for malaria).
We were invited by Davidson Gwatkin to hold an Equity Interest Group meeting at the Washington Conference on the World Bank Reaching the Poor Program (February 2004). We have continued this collaboration by inviting Davidson Gwatkin to join our Equity Planning Group, including participation at the Ottawa methods workshop in February 2007.
Next steps: We aim to explore the methodological issues of conducting Cochrane/Campbell reviews to assess the role of different knowledge translation strategies.
1.4 Applicability of Campbell and Cochrane reviews to equity-relevant clinical guidelines
Clinical Practice Guidelines are recognized as one way to inform clinicians of the best available evidence, in a format that is useful in practice. With major funding from the Rockefeller Foundation, INCLEN is developing methods for creating equity-focused and locally relevant clinical practice guidelines. These methods include applying an equity lens to existing clinical practice guidelines (Dans 1998), as well as developing new recommendations using a modification of the GRADE Working Group methods (led by Andy Oxman). The GRADE Working Group has acknowledged the importance of equity factors by proposing that equity considerations be reflected in separate recommendations. The extent to which Campbell and Cochrane reviews can play a role as the source of evidence for these separate recommendations depends on the availability of equity information in reviews.
We have collaborated with Tamara Rader of the Cochrane Musculoskeletal Group and Nancy Santesso of the Cochrane Summary of Findings Test Project on summary of findings (SoF) tables and an equity lens. Based on the latest SoF from the Test Project, Jessie McGowan, our Trial Search Coordinator, has been developing a Health Professionals Template. The template is a tool which enables people to create Cochrane review summaries aimed at health professionals; it includes clear guidelines for use.
Next steps: We are working with the GRADE Working Group on methods for developing equity-focused and locally relevant recommendations. This will include an assessment of the information on equity factors that need to be reported in Campbell and Cochrane reviews in order to be used as part of these guidelines.
2.0 The use of equity implications to inform policy development
In order to inform evidence-based policy decisions (and be relevant to decision-makers), there is a need for consideration of equity factors in systematic reviews (Liberatos 1998, Mackenbach 2003). Most reviews present information on effectiveness in terms of averages, without providing any indication as to how effective interventions are for poor people, or how effective they might be in reducing the rich-poor gap. This gap was identified in several of our supporting letters. This gap is also important for Health Technology Assessment (HTA), as discussed earlier, and we have submitted for funding to develop these methods as a major refinement in HTA methodology.
Next steps: Conduct a needs assessment of health policy makers' decision-making needs with respect to making decisions about health equity, policies and programs and using systematic reviews. A proposal has been submitted for funding from the Canadian Coordinating Office of Health Technology Assessment. Leads: Peter Tugwell, Jan Hatcher-Roberts, Nadia Hamel.
3.0 Cost-equity
We will develop methods for assessing the cost-equity of interventions. Decision-makers need to take into account not only costs and effectiveness (as in traditional cost-effectiveness), but also whether the intervention will reduce the rich-poor gap in health. Miranda Mugford, from the Campbell and Cochrane Economics Methods Group has strongly supported this application, both with a supporting letter and by attending our meeting in Barcelona. The Economics Methods Group is keen to collaborate on assessing fair allocation of resources and efficiency. The economics group has not yet developed a special interest group to deal with this area.
Next steps: Develop methods for assessing public preferences for equity (ie reducing the rich-poor gap) and incorporating these into cost-effectiveness. We hypothesize that this will show that the general public is willing to pay extra money to help the poorest people. This will include developing methods for calculating cost-equity using Campbell and Cochrane reviews as the source of efficacy data.
4.0 Differences in risk and response in disadvantaged groups
The disadvantaged may be at a greater risk for poor health (greater baseline risk or burden of illness), and also are likely to have a poorer response to therapy or interventions.
Next steps: We propose to conduct empirical methods research on how differences in risk and response contribute to calculations of number needed to treat and impact. These methods will lead to innovations in the way the bottom-line or lay summary of reviews are formatted for different subgroups.
5.0 Measurement of equity factors in systematic reviews
How should Campbell and Cochrane reviewers consider equity factors in their systematic reviews? Definitions of equity and disadvantage vary. For example, disadvantage has been measured in many ways, including social class, education, dwelling size, income, consumption and ownership of certain assets (which can be represented in wealth indices) (Wagstaff 2003, Houweling 2003). There is some controversy whether different measures and different wealth/asset indices affect the calculation and description of inequities (Wagstaff 2003). In a review of intervention studies, Gepkens and Gunning Schepers (1996) found that there was little standardization of methodology and measures of health inequalities and the impact of interventions on health inequalities. This makes it difficult to compare results across studies. Campbell and Cochrane reviewers need advice on the appropriate methods for systematic reviews.
Ogilvie and Petticrew (2003) found that Cochrane reviews rarely present information on outcome stratified by socioeconomic position and suggest that differential effects are not often considered in the design of the review. We have also found that 62% of a random sample of Cochrane reviews reported one or more of a list of: place of residence, race/ethnicity, education, gender, religion, occupation, socioeconomic status and social capital (Tsikata 2003). However, only 1 out of 95 Cochrane reviews presented information on the different effects of interventions according to socioeconomic status.
Next steps: We are testing a method of collecting data on health equity using an acronym called "PROGRESS" for measuring disadvantage, developed by Hilary Brown and Tim Evans (Rockefeller Foundation). PROGRESS stands for Place of residence, Race/ethnicity, Occupation, Gender, Religion, Education, Socioeconomic Status (income or composite measures), and Social capital. Empirical methods work is underway on the feasibility of collecting this data, and its usability and usefulness as part of Campbell and Cochrane reviews.
6.0 Modelling (statistical techniques)
Complex interactions of environment, society, culture and biology contribute to health inequalities. Mathematical and statistical models provide one way to test the impact of varying individual or combinations of factors, and how they are affected by policy decisions, such as implementing a new program or intervention. Campbell and Cochrane reviews are an excellent source of the efficacy of interventions in these models. However, information on the population, environment, setting, context and interventions, that are required from reviews for modelling, is often not presented.
Next steps: We are developing a policy model for osteoporosis and osteoarthritis that will include interactions of social, cultural, environmental factors on fractures and total joint replacement. This methods work will propose standards for data required on setting, context, and environment that relate to health equity.
7.0 Finding controlled studies on health equity
We have learned that it is difficult to determine whether studies report data by socioeconomic status from the abstracts retrieved by electronic literature searches, particularly when the focus is on clinical interventions. Relevant evidence will include not only RCTs but, as with the Cochrane Effective Practice and Organisation of Care Group, interrupted time series and controlled before and after studies. These latter types of study for equity-enhancing interventions are difficult to identify in electronic searches.
Next steps: We are conducting a methods study of which indexing terms are most likely to be associated with equity-relevant articles (McGowan 2003). We have also contacted the National Library of Medicine about the feasibility of developing new indexing terms that will help identify equity-relevant studies.
8.0 Statistical issues around socioeconomic subgroup analyses
Many of these social interventions are quite complex, and incorporate a number of different outcomes, study designs, and methods. There is therefore likely to be considerable heterogeneity. Qualitative analysis and process evaluation may help with data analysis and interpretation. Furthermore, many primary studies are small, and stratified analyses by socioeconomic position will often include only small numbers in each group limiting the power to detect differences between socioeconomic strata.
David Ogilvie and Mark Petticrew (MRC SPHSU), Amanda Sowden (CRD/York), and Margaret Whitehead (Liverpool) received funding to test the feasibility of methods for using existing systematic reviews and their primary studies to assess the effects on inequalities of macro-level tobacco control interventions. Their findings were presented at the Campbell Colloquium in London, England (May, 2007).