The evidence arena: a multilevel playing field

Abstract

Health problems are often perceived as problems of individuals who struggle to develop a healthier life style or to find effective treatment. But this is by far not the whole story. In promoting healthy living, contextual factors play an essential–and sometimes the most important - role. And for good prevention and care appropriate staff, knowledge and expertise, and state-of-the-art health care services must be available. Regarding lifestyle, obesity is a clear example of the complex interactions of many factors at various levels, such as: genetic predisposition, nurturing, individual behavior, food consumption patterns in people's social network, access to healthy food, income, education, the school and work environment, opportunities for physical mobility and sports, societal and subgroup-related norms and values, and the interests and policies of the food industry and governments [1Cunningham-Myrie C.A. Theall K.P. Younger N.O. Mabile E.A. Tulloch-Reid M.K. Francis D.K. et al.Associations between neighborhood effects and physical activity, obesity, and diabetes: the Jamaica Health and Lifestyle Survey 2008.J Clin Epidemiol. 2015; 68: 970-978Abstract Full Text Full Text PDF PubMed Scopus (21) Google Scholar, 2Mazarello Paes V. Ong K.K. Lakshman R. Factors influencing obesogenic dietary intake in young children (0-6 years): systematic review of qualitative evidence.BMJ Open. 2015; 5: e007396Crossref PubMed Scopus (84) Google Scholar, 3Mackenbach J.D. Lakerveld J. Van Lenthe F.J. Teixeira P.J. Compernolle S. De Bourdeaudhuij I. et al.Interactions of individual perceived barriers and neighbourhood destinations with obesity-related behaviours in Europe.Obes Rev. 2016; 17: 68-80Crossref PubMed Scopus (15) Google Scholar]. With respect to treatment and care, a self-evident example of a key contextual factor is the inequality in available healthcare services within and between countries, depending on individual and national incomes, types of healthcare and insurance systems [[4]GBD 2016 Healthcare Access and Quality CollaboratorsMeasuring performance on the Healthcare Access and Quality Index for 195 countries and territories and selected subnational locations: a systematic analysis from the Global Burden of Disease Study 2016.Lancet. 2018; 391: 2236-2271Abstract Full Text Full Text PDF PubMed Scopus (477) Google Scholar]. In such a complex whole of factors, actors and interests, well-targeted input of the best available evidence is a necessary condition for achieving optimal health outcomes for individuals and populations. Researchers in the field of clinical and applied health sciences should therefore not only have the skills to make the reductions needed to thoroughly study specific questions related to specific mosaic pieces, but must also be able to connect new evidence with the whole picture, from clinical guidelines to health policy. But this is not a sufficient condition. First, because evidence will never cover the complex reality of decision making in full. And second, since multiple other influences at various societal levels play a role and will continue to do so. In this connection, one could speak about the ‘evidence arena’: the complex multilevel context of factors, actors and interests in which evidence has to be produced, disseminated, and optimally utilized. The commentary by Van der Heide et al., published in this issue, is an excellent demonstration of how this evidence arena can be approached. They focus on the importance of health literacy in chronic disease management, increasingly recognized as a much more frequent phenomenon than many of us would have expected today. The authors especially elaborate health literacy as ‘a matter of interaction’, and emphasize that health literacy is ‘not merely a matter of individual skills but that it is highly dependent on the accessibility of health-care systems, the communication skills of health-care professionals, and the level of complexity of the health information’. At the same time, they show that the literature indicates that research health literacy is mainly handled as an individual attribute, rather than also including the health-care context. Van der Heide et al. underline ‘the importance of interpreting the concept of health literacy as a dynamic construct that emerges from the interaction between patients/citizens and health-care systems, organizations, and professionals.’ They make the case that understanding the link between health literacy and chronic disease management is important for the development of comprehensive measurement instruments and interventions to enhance health literacy. Another element of the evidence arena is the ongoing debate on research methods. A good example is the debate on how qualitative and quantitative research methods relate to each other, given the different traditions and strengths of these approaches. Related to this is the importance of mixed methods approaches getting more mainstream than currently seems the case, to tackle the complex problems in health and healthcare [[5]Tugwell P. Knottnerus J.A. McGowan J. Tricco A.C. Systematic Review Qualitative Methods Series reflect the increasing maturity in qualitative methods.J Clin Epidemiol. 2018; 97: vii-viiiAbstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar], and the question of how different sources of evidence should be best summarized in order to optimally serve patient decision making. Sale and colleagues argue that qualitative inquiry is essential to the scientific process. They propose that qualitative research should be considered a fundamental scientific enterprise, which implies a broad perspective on the systematic accumulation of knowledge. In their view, qualitative research ‘generates meaning through a systematic approach to induction and deduction, and thus is essential to the scientific method in the pursuit of knowledge’. As editors, we find it both important and fruitful to combine the strengths of well-designed and performed qualitative and quantitative research. We think of these in the context of a continuum, or a spectrum, rather than being separate worlds. One could say that there is no quantity without quality (e.g., identical quantitative data have completely different meanings when different topics are addressed), and there is no quality without quantity (since qualitative observations will always have some comparative components, at least implicitly related to e.g., volume or frequency). These two aspects have often complementary or combined roles through the various phases of research. For example, in a phase of creation of ideas or in the process of hypothesis generation, detailed individual clinical observations and descriptions of the first few cases are crucial. If these lead to promising ideas or hypotheses, large and costly studies can be developed, financed and performed to quantitatively test them. Furthermore, in applying quantitative findings in practice, individual patient-related, qualitative considerations again play a prominent role. Indeed, during the whole research process combining and integrating qualitative and qualitative aspects is important, e.g., when it comes to patient-centered observations, measurements, outcomes, and perceptions. In an era of taking steps forward in personalized prevention, medicine and care, these insights should not be a surprise. An example of successful mixed methods research, published in this issue, is the work of Dela Vega c.s. on the status of dementia care services in hospitals and geriatric care facilities, in which interviews, focus group discussions, and a survey of health care workers were used. This approach ‘helped identify service and health workforce needs and elucidate understanding of health workers’ attitude and perceptions toward a disease of which there is low knowledge and awareness'. Indeed, this type of research is highly relevant to support appropriate health services policies focused on organizing and improving patient care. Also in achieving evidence summarization to support patient decisions. multiple evidence sources are being used. This is demonstrated in the study of Dannenberg et al., who evaluated the evidence summarization process of organizations that develop patient decision aids and assessed whether their processes justify confidence that these patient decision aids are trustworthy. Based on a survey among 23 organizations, they found that most of these use multiple approaches for identifying evidence, such as systematic reviews, clinical practice guidelines, nonsystematic reviews, primary studies, and clinical consensus statements. Many also ask patients about their experience of living with their illness and treatments, and include this information in the decision aids. But while using multiple sources is important, there is also concern: the authors found that the processes that organizations use to summarize the evidence to be included in the decision aids are not standardized. They emphasize that, since patient decision aids can have substantial impact on patients’ treatment or screening decisions, it is important that their information content is accurate, free from bias and up to date as much as possible. This certainly needs much more attention in the evidence arena, in which healthcare providers and patients must effectively collaborate to optimize health care, based on the best possible evidence. Speaking about collaboration in the evidence arena: the importance of integrating stakeholders' views in prioritizing the work of scientific professionals is increasingly recognized. Scott c.s. report the results of a prioritization project to identify highest priority systematic review topics in the field of treatment and prevention of acute respiratory infections. For this purpose, they analyzed the gap between existing randomized controlled trials and Cochrane systematic reviews, and performed a two-round international prioritization survey among clinicians, researchers, systematic reviewers, allied health, patients, and careers. This process generated a list of priority systematic review topics. The authors conclude that stakeholder involvement enhanced the transparency of the process and expect increased relevance of their Cochrane review group's work to stakeholders. Indeed, this approach can help to ensure that the available capacity to produce reviews is utilized as efficiently as possible.