What’s in a mechanism? Development of a key concept in realist evaluation

Background: The idea that underlying, generative mechanisms give rise to causal regularities has become a guiding principle across many social and natural science disciplines. A specific form of this enquiry, realist evaluation is gaining momentum in the evaluation of complex social interventions. It focuses on ‘what works, how, in which conditions and for whom’ using context, mechanism and outcome configurations as opposed to asking whether an intervention ‘works’. Realist evaluation can be difficult to codify and requires considerable researcher reflection and creativity. As such there is often confusion when operationalising the method in practice. This article aims to clarify and further develop the concept of mechanism in realist evaluation and in doing so aid the learning of those operationalising the methodology. Discussion: Using a social science illustration, we argue that disaggregating the concept of mechanism into its constituent parts helps to understand the difference between the resources offered by the intervention and the ways in which this changes the reasoning of participants. This in turn helps to distinguish between a context and mechanism. The notion of mechanisms ‘firing’ in social science research is explored, with discussions surrounding how this may stifle researchers’ realist thinking. We underline the importance of conceptualising mechanisms as operating on a continuum, rather than as an ‘on/off’ switch. Summary: The discussions in this article will hopefully progress and operationalise realist methods. This development is likely to occur due to the infancy of the methodology and its recent increased profile and use in social science research. The arguments we present have been tested and are explained throughout the article using a social science illustration, evidencing their usability and value

Friend or foe? The current epidemiologic evidence on selenium and human cancer risk.

Scientific opinion on the relationship between selenium and the risk of cancer has undergone radical change over the years, with selenium first viewed as a possible carcinogen in the 1940s then as a possible cancer preventive agent in the 1960s-2000s. More recently, randomized controlled trials have found no effect on cancer risk but suggest possible low-dose dermatologic and endocrine toxicity, and animal studies indicate both carcinogenic and cancer-preventive effects. A growing body of evidence from human and laboratory studies indicates dramatically different biological effects of the various inorganic and organic chemical forms of selenium, which may explain apparent inconsistencies across studies. These chemical form-specific effects also have important implications for exposure and health risk assessment. Overall, available epidemiologic evidence suggests no cancer preventive effect of increased selenium intake in healthy individuals and possible increased risk of other diseases and disorders

Inhibin secretion during the rat estrous cycle: Relationships to FSH secretion and FSH beta subunit mRNA concentrations

Serum inhibin and FSH and FSH beta subunit mRNA levels were measured at 3h intervals throughout the 4 day estrous cycle in female rats and hourly between 1000 and 2400 h of proestrus. On proestrus, serum inhibin concentrations fell during the late morning-early afternoon, then increased transiently during the late afternoon gonadotropin surges. Inhibin levels decreased during the late evening of proestrus, coincident with the FSH surge-related rise in FSH beta mRNA levels. Serum inhibin remained relatively stable during estrus and early metestrus, but rose during the late evening of metestrus and remained elevated until early diestrus. FSH beta mRNA levels were elevated on late estrus and early metestrus and declined during the evening of metestrus as serum inhibin levels increased. These data show that concetrations of serum inhibin change during the estrous cycle and that a general inverse relationship exist between serum inhibin and FSH levels and FSH beta mRNA concentrations in the pituitary. This suggests that inhibin may inhibit FSH beta gene expression and FSH secretion during the 4 day cycle in female rats.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28957/1/0000794.pd

The influence of contextual factors on healthcare quality improvement initiatives:what works, for whom and in what setting? Protocol for a realist review

Background  Context shapes the effectiveness of knowledge implementation and influences health improvement. Successful healthcare quality improvement (QI) initiatives frequently fail to transfer to different settings, with local contextual factors often cited as the cause. Understanding and overcoming contextual barriers is therefore crucial to implementing effective improvement; yet context is still poorly understood. There is a paucity of information on the mechanisms underlyinghowandwhyQI projects succeed or fail in given settings. A realist review of empirical studies of healthcare QI initiatives will be undertaken to examine the influence and impact of contextual factors on quality improvement in healthcare settings and explore whether QI initiatives can work in all contexts.  Methods  The review will explore which contextual factors are important, and how, why, when and for whom they are important, within varied settings. The dynamic nature of context and change over time will be explored by examining which aspects of context impact at key points in the improvement trajectory. The review will also consider the influence of context on improvement outcomes (provider- and patient-level), spread and sustainability. The review process will follow five iterative steps: (1) clarify scope, (2) search for evidence, (3) appraise primary studies and extract data, (4) synthesise evidence and draw conclusions and (5) disseminate findings. The reviewers will consult with experts and stakeholders in the early stages to focus the review and develop a programme theory consisting of explanatory ‘context–mechanism–outcome’ configurations. Searches for primary evidence will be conducted iteratively. Data will be extracted and tested against the programme theory. A review advisory group will oversee the review process. Review findings will follow RAMESES guidelines and will be disseminated via a report, presentations and peer-reviewed publications.  Discussion  The review will update and consolidate evidence on the contextual conditions for effective improvement and distil new knowledge to inform the design and development of context-sensitive QI initiatives. This review ties in with the study of improvement programmes as vehicles of change and the development of an evidence base around healthcare improvement by addressing whether QI initiatives can work in all contexts.  Systematic review registration  PROSPERO CRD4201706213

Policymakers\u27 experience of a capacity-building intervention designed to increase their use of research: A realist process evaluation

Background: An intervention’s success depends on how participants interact with it in local settings. Process evaluation examines these interactions, indicating why an intervention was or was not effective, and how it (and similar interventions) can be improved for better contextual fit. This is particularly important for innovative trials like Supporting Policy In health with Research: an Intervention Trial (SPIRIT), where causal mechanisms are poorly understood. SPIRIT was testing a multi-component intervention designed to increase the capacity of health policymakers to use research. Methods: Our mixed-methods process evaluation sought to explain variation in observed process effects across the six agencies that participated in SPIRIT. Data collection included observations of intervention workshops (n = 59), purposively sampled interviews (n = 76) and participant feedback forms (n = 553). Using a realist approach, data was coded for context-mechanism-process effect configurations (retroductive analysis) by two authors. Results: Intervention workshops were very well received. There was greater variation of views regarding other aspects of SPIRIT such as data collection, communication and the intervention’s overall value. We identified nine inter-related mechanisms that were crucial for engaging participants in these policy settings: (1) Accepting the premise (agreeing with the study’s assumptions); (2) Self-determination (participative choice); (3) The Value Proposition (seeing potential gain); (4) ‘Getting good stuff’ (identifying useful ideas, resources or connections); (5) Self-efficacy (believing ‘we can do this!’); (6) Respect (feeling that SPIRIT understands and values one’s work); (7) Confidence (believing in the study’s integrity and validity); (8) Persuasive leadership (authentic and compelling advocacy from leaders); and (9) Strategic insider facilitation (local translation and mediation). These findings were used to develop tentative explanatory propositions and to revise the programme theory. Conclusion: This paper describes how SPIRIT functioned in six policy agencies, including why strategies that worked well in one site were less effective in others. Findings indicate a complex interaction between participants’ perception of the intervention, shifting contextual factors, and the form that the intervention took in each site. Our propositions provide transferable lessons about contextualised areas of strength and weakness that may be useful in the development and implementation of similar studies