Table 2.

Key findings from peer-reviewed articles

Authors/title/method	Research question/aim	Main process(es)	Definitions	Mechanisms involved in spread/scale-up/sustainability	Factors that facilitate or impede spread/scale-up/sustainability
Greenhalgh et al., Diffusion of innovations in service organizations: systematic review and recommendations (United Kingdom) [63]	Propose an evidence-based conceptual framework for sustaining innovations	Spread Sustainability	Diffusion: passive spread of innovation Sustainability: making an innovation routine until it reaches obsolescence	Natural, emergent Social Technical Managerial	Innovation system fit Receptive capacity Support and advocacy Dedicated time and resources Opinion leaders and champions Receptive context Interorganisational network, collaboration and boundary spanners
Ferlie et al., The non-spread of innovations: the mediating role of professional (United Kingdom) [64] Two qualitative studies drawing on eight comparative and longitudinal case studies of innovation careers (healthcare and other)	Develops a new theory to explain barriers to spread by asking (1) Are innovation pathways in healthcare linear or messy? (2) Is robust scientific evidence sufficient to lead to successful diffusion? (3) What impact does greater innovation complexity have?	Spread	Spread of healthcare innovations: a slow, complex and contested process, which can be enacted within and across geographical, professional and sectoral boundaries	Crossing boundaries Spreading innovation in multi-professional organisations as a non-linear process	Social and cognitive boundaries between professionals
Slaghuis et al., A framework and a measurement instrument for sustainability of work practices in long-term care (Netherlands) [65]	Develop a theoretical framework and measurement instrument for sustainability	Sustainability	Sustainability: a dynamic process in which actors in a targeted work practice develop and/or adapt organisational routines to a new work method Lacks a theoretical definition and conceptualisation	Routinising Institutionalising	Fit between innovation and work practices, internal structures and dynamics, organisational contexts and institutional orders Dynamism of the process Interorganisational relationships
Norton et al., A stakeholder-driven agenda for advancing thescience and practice of scale-up and spread in health (United States of America) [66] Recommendations from a state-of-the-art conference and follow-up activity to operationalise and prioritise recommendations	Identify gaps and galvanise interest and activity in scale-up and spread of effective health programmes	Spread Scale	Spread and scale: interchangeable terms – deliberate efforts to increase the impact of innovations successfully tested in pilot or experimental projects to benefit more people and to foster policy and programme development on a lasting basis Lack universally accepted definitions	Tracking and sharing information regarding ongoing policy, practice and research in scale-up supported by database and means (e.g. email groups, conference calls, meetings); evidence on when, where and how particular methods are more or less effective, and standardised measures of scale-up and spread	Institutional Review Board regulations of healthcare organisations and systems Funding opportunities and financial incentives to support spread and scale Human resources, capacity and expertise Learning activities that link stakeholders together to share new concepts, critique ongoing scale-up activities Real-time collection of qualitative and quantitative data to guide ongoing adaptations
Lanham et al., How complexity science can inform scale-up and spread in health care: Understanding the role of self-organization in variation across local contexts (Kenya) [24]	Examine the role of self-organisation in the scale-up and spread of effective healthcare practices	Scale-up Spread	Scale-up and spread: efforts (concept, process or practice) to disseminate and implement a successful intervention across systems	Sense-making and interdependencies among stakeholders can facilitate self-organisation processes that increase the probability of spreading effective practices across diverse settings, while acknowledging unpredictability	Understanding of how local context shapes intervention implementation in healthcare contexts Recognition of challenges of behaviour change in healthcare delivery Infrastructure Real-time insights Focus on reproducing interventions with total fidelity, overlooking the unique attributes of local contexts Assumption that innovation is static during the adoption process Connectedness or interrelatedness among project team members
Ploeg et al., Spreading and sustaining best practices for home care of older adults: a grounded theory study (Canada) [67] Development of research-based model	What is the process used to spread best practices related to caring for older adults within home care agencies? What factors influence spread or non-spread?	Spread Scale-up	Spread: process through which new working methods developed in one setting are adopted, perhaps with appropriate modifications, in other organisational contexts Scale-up: no definition mentioned Absence of widely agreed definitions of the terms ‘spread’ and ‘scale-up’	Committing to change Implementing on a small scale, adapting locally, addressing potential barriers Spreading internally to multiple users and sites, then disseminating externally along pathways that are elusive and non-linear with erratic, circular or abrupt processes	Passionate and committed leadership: project leads, champions, managers and steering committees Manager turnover Time and resources Feedback to see benefits
Brewster et al., Integrating new practices: a qualitative study of how hospital innovations become routine (United States of America) [68] Study of hospitals participating in the STAAR initiative in Massachusetts, Michigan (2009–2013)	Examine the process of integrating newly adopted practices into routine hospital operations in order to characterise the mechanisms through which integration occurs	Sustainability	None mentioned	Integrating mechanisms that correspond to different innovation characteristics Innovations that are intrinsically rewarding to the staff, by making their jobs easier or more gratifying, become integrated through shifts in attitudes and norms over time. Innovations with lower innovation-value fit require a different set of integrating mechanisms. Automation of innovation decouples the innovation from staff behaviour when staff did not perceive benefits to themselves Careful monitoring, proactive reminders and problem solving	Visible improvements in outcomes and concrete benefits to staff Passive or active resistance Organisational commitment signalled by senior leaders Continuity of key personnel who can train others and sustain effort while more permanent integrating mechanisms began to work Revised performance standards
Milat et al. (2015) Narrative review of models and success factors for scaling up public health interventions (Australia) Synthesise evidence on scaling up public health interventions into population-wide policy and practice	Define and describe frameworks, processes and methods of scaling up public health initiatives	Scale-up	Scale-up: process by which health interventions shown to be efficacious on a small scale and or under controlled conditions are expanded under real world conditions into broader policy or practice The terms scaling up and scalability have been applied in different ways and contexts with little consistency	Costing and economic modelling of intervention approaches Monitoring implementation of innovation based on data that is linked to decision-making throughout the scaling up process, and a range of implementers and the target community are involved in tailoring the scaled-up approach to the local context	Systematic use of evidence Simplicity of the intervention Ease with which individual intervention components are understood and adopted by key stakeholders and target audiences Infrastructure to support implementation, monitoring and evaluation Political will Clear strategy and strong advocacy Strong leadership and governance Participatory approaches and active engagement of a range of implementers and of the target community
Milat et al. (2014) Increasing the scale and adoption of population health interventions: experiences and perspectives of policy makers, practitioners, and researchers (Australia) Delphi technique	Articulate the processes of how decisions to scale up interventions are made, the role of evidence, and contribution of different professional groups Present perspectives of senior researchers and policy-makers regarding concepts of ‘scaling Generate an agreed definition of ‘scalability’ Identify intervention and research design factors perceived to increase the potential for interventions to be ‘scaled up’	Scale-up	Scalability: the ability of a system, network or process, to handle growing amounts of work in a graceful manner Scale has not been adequately defined in the health promotion literature	Focussing on individual scalability considerations will vary according to intervention attributes, context and the stage of an intervention’s strategic development	Effectiveness, reach and adoption Workforce, technical and organisational resources required Cost considerations Intervention delivery Contextual factors Appropriate evaluation approaches
Milat et al., A guide to scaling up population health interventions (Australia) [69] Systematic review and Delphi technique to offer a four-step guide to scale up an innovation	Develop a guide on how to scale up health interventions, balancing desirability and feasibility	Scale-up	Scale-up: deliberate efforts to increase the impact of successfully tested health interventions to benefit more people and to foster policy and programme development on a lasting basis	Assessing the suitability of the intervention for scaling up includes effectiveness, potential reach and adoption, alignment with the strategic context, acceptability and feasibility Planning scale-up while outlining a vision and compelling case for action, determines who could be involved and what their role will be, considers options for evaluation and monitoring, estimates resources required, secures resources, and builds a foundation of legitimacy	Effect size of the intervention given that effects are likely to be smaller as they are scaled up Local context and the organisational, financial and human resources Formative evaluation to test appropriateness Acceptability of the scaled-up intervention with the target audience and other stakeholders Resources for specific data collection efforts: evaluation and monitoring efforts to show effectiveness over time, rates of reach and adoption, acceptability, compatibility with existing interventions and costs Validity of performance measures and understanding of the limitations of using performance data to inform decision-making Effort to strengthen organisations Coordinated action and governance
Gupta et al., Promoting development and uptake of health innovations: The Nose to Tail Tool [version 1; referees: 3 approved, 1 approved with reservations] (Canada) [70] Scoping review on development of the Nose to Tail Tool	Identify articles that described the scale-up process conceptually or that described an instance in which a healthcare innovation was scaled up Help stakeholders identify the stage of maturity of their innovation, consider each major stakeholder group and contextual barriers	Scale-up	Scale-up: the expansion and extension of delivery or access to an innovation for all end users in a jurisdiction that will benefit from it	Scale-up requires two steps – first spreading to similar settings (expansion) followed by spreading to different settings (extension) Commonly described stages of scaling innovation: identify the problem; develop the innovation; design, conduct, evaluate the pilot test; implementation planning, implementation and evaluation; test for extensibility; scale-up evaluation and monitoring; institutionalisation	Stage of maturity of the innovation and nature of the innovation (discrete, multicomponent or paradigmatic) Clear view of resources required Clear view of the importance of politics and policy Simultaneous attention to vertical or horizontal spread of innovations Opportunity to redesign the innovation at an early stage or cease work on the project before too much has been invested Testing for extensibility Understanding of the interests of key stakeholders, including innovators, end users and decision-makers The social, physical, regulatory, political and economic environment
Greenhalgh et al., Beyond adoption: a new framework for theorizing and evaluating non-adoption, abandonment, and challenges to the scale-up, spread, and sustainability of health and care technologies (United Kingdom) [13] Longitudinal ethnography and action research across more than 20 organisations	Produce an evidence-based, theory-informed, accessible and usable framework Enable those seeking to design, develop, implement, scale up, spread and sustain technology-supported health or social care programmes to identify and address key challenges in different domains and the interactions between them Inform design of new technology, identify technology that has limited chance of scale-up, plan and roll out a technology plan, and learn from programme failures	Scale-up Spread Sustainability	Scale-up: business as usual locally Spread: transferable to new settings Sustainability: maintained long term through adaptation to context over time	Acting collectively and reflexive monitoring help fill crucial gap between the nuanced, flexible and often unpredictable nature of human activity and what it is possible to deliver technically	Complexity of the innovation, clear view of its value proposition and dependability Complexity of the organisation(s) and the wider (institutional and societal) context: degree of readiness, absorptive capacity Technology fit with existing organisational routines Ability to adapt and evolve over time: interaction and mutual adaptation over time between technology, patient, staff and team, with opportunities for sense making of the innovation Complexity in external issues (financial, governance, regulatory, legal, policy), especially reimbursement Devolved organisational structure (with each department or unit able to make semiautonomous decisions) Organisational slack (spare resources available for new projects) Strong leadership, good managerial relations, a risk-taking climate (staff are rewarded rather than punished for trying things out) Resistance or rejection by intended users Ability to shift to new ways of working, or support the extensive work needed to implement and sustain the change
Lennox et al., What makes a sustainability tool valuable, practical and useful in real world healthcare practice? A mixed methods study on the development of the Long Term Success Tool in Northwest London (United Kingdom) [71] A scoping review, group discussion, stakeholder event, interviews and small pilot project	How do sustainability factors identified in the literature resonate with the experience of those in improvement projects in healthcare? Design and test the usability of the tool with healthcare improvement teams	Sustainability	Sustainability: a dynamic process where staff and others involved have the capacity and capability to monitor and modify activities and interventions in relation to the health benefits they wish to achieve and in response to threats and opportunities that emerge over time Several definitions of sustainability in the literature and little consensus on what constitutes ‘achieving sustainability’	Identifying risks to sustainability can create an environment for team members to receive ongoing feedback, highlight specific actions to be taken and comment on ways to influence sustainability over time Acknowledging that sustainability is a process and not an end point, and does not include a specific time frame	Understanding of the relationship between achieving initial ‘successful’ implementation and achieving long-term sustainability Tool design and content Construct design: adequate coverage of items and clear definitions Practical usefulness in real-world healthcare settings Commitment to and support for the improvement Leadership Team functioning Resources, involvement, skills and capabilities Monitoring for feedback and learning: evidence of benefits Process adaptability and robustness Alignment with organisational culture and priorities Alignment with external political and financial environment
Charif et al., Effective strategies for scaling up evidence-based practices in primary care: a systematic review (Canada) [9]	Identify effective strategies for scaling up evidence-based practices in primary care	Scale-up	Scale up: a systematic approach often used in the context of rolling out a successful local programme to regional, national or international levels The term ‘spread’ is commonly used interchangeably with ‘scale up’ Spread: organic process of the diffusion of a local improvement within a health system There is a lack of consensus within the field regarding terminology	Reporting of both a denominator (number of targeted units) and a numerator (number of units covered by the evidence-based practice), in combination with impact measurements Involving strategies related to human resources (policy-makers/managers, providers, external medical consultants and community healthcare workers), infrastructure (new buildings, linkages between different clinical sites), policy/regulation and financing (paying bonuses to healthcare workers), and patient involvement	Human resources Lack of theories, frameworks or strategies to support implementation
Shaw et al., Studying scale-up and spread as social practice: theoretical introduction and empirical case study (United Kingdom) [12]	At an empirical level, what explains the difficulties with spread and scale-up for a particular technology? At a more theoretical level, what kind of insights can a social practice approach provide that will inform the study of spread and scale-up for technological innovations in health and care more generally?	Scale up Spread	Scale up: increase local usage Spread: extend usage to new localities and settings	Balancing the needs of context-sensitivity with the realities of producing technologies that have potential for mass application Coordinating and stabilising shared practices and routines; adoption of a new technology requires changes in the practices adopted by both professional and lay caregivers, and in particular embedding health and care technologies within sociotechnical networks and through situated knowledge, personal habits and collaborative routines. A technology that ‘works’ for one individual in a particular set of circumstances is unlikely to work in the same way for another in a different set of circumstances	Creativity and compassion to generate individual solutions Human relationships and situated knowledge Deep understanding of the complex and situated nature of technology use Clash between the innovation and the actual social practices of real actors