The Greenhalgh model – an easy summary

The following article contains a concise summary of the key components of an influential model developed by Greenhalgh, Robert, Macfarlane, Bate and Kyriakidou (2004). Greenhalgh and her colleagues conducted an extensive literature review to identify which factors play a role in spreading and sustaining innovations in health service delivery and organisations. The resulting article is a highly recommended read, and some of the main findings are summarised below.

Basic terminology Greenhalgh
  • Innovation: A novel set of behaviours, routines, and ways of working that are directed at improving health outcomes, administrative efficiency, cost effectiveness, or users’ experience and that are implemented by planned and coordinated actions.
  • Diffusion: Passive spread of an innovation (informal, unplanned). It’s a group phenomenon.
  • Dissemination: Active and planned efforts to persuade target groups to adopt an innovation.
  • Implementation: Active and planned efforts to mainstream an innovation within an organization.
  • Sustainability: Making an innovation routine until it reaches obsolescence.
  • Adoption: Adoption is an individual process detailing the series of stages one undergoes from first hearing about a product to finally adopting it.
  • Assimilation: When the unit of adoption is not an individual, but a more complex system/team/department/organization, we usually refer to this as assimilation instead of adoption.


Figure: Visualisation of Greenhalgh et al.’s (2004) model

From here on forward: bold, cursive terms are not directly represented in the model above, but are nevertheless important components of Greenhalgh et al.’s (2004) theory.

1. The innovation

An innovation will be more easily adopted, when the following characteristics apply:

  • Relative advantage: A clear, unambiguous advantage in either effectiveness or cost-effectiveness.
  • Compatibility: Compatible with the intended adopter’s values, norms, and perceived needs.
  • Low complexity: Perceived as being simple to use.
  • Trialability: The intended user has room to experiment to some extent with the innovation.
  • Observability: Benefits are visible to intended adopters.
  • Reinvention: The possibility to adapt, refine or modify an innovation to suit an adopter’s specific needs.
  • Fuzzy boundaries: A degree of adaptiveness of the “soft periphery” (organizational structures/systems required for fully implementing an innovation).
  • Low Risk: The innovation has a low level of perceived risk / low uncertainty in outcome.
  • Task issues: The innovation is relevant to the performance of work and task performance.
  • Nature of knowledge required: The knowledge required to use the innovation can be codified and transferred from one context to another.
  • Technical support: The innovations is supported by training, help desk and customization support.


2. Adopter
  • Needs
  • Motivation
  • Values and goals
  • Skills
  • Learning style
  • Social networks


  • General psychological antecedents: Individual traits associated with the propensity to try out and use innovations (e.g. tolerance for ambiguity, intellectual ability, motivation, values, learning style).
  • Context-specific psychological antecedents: An intended adopter who is motivated and able (in terms of values, goals, skills) to use a particular innovation is more likely to adopt it. If the innovation meets an identified need by the intended adopter, adoption is more likely.
  • Meaning: The meaning of an innovation for the intended adopter has a strong influence on the adoption decision. If the meaning attached to the innovation by individual adopters matches the meaning attached by top management, service users, and other stakeholders, the innovation is more likely to be assimilated.
    The meaning attached to an innovation can often be negotiated and reframed, through discourse within the organization or across organizational networks.
  • The adoption decision: An individual’s decision to adopt an innovation is rarely independent of other decisions. It may be:
    • Contingent: Dependent on a decision made by someone else in the organization.
    • Collective: The individual has a ‘vote’ but ultimately must respect the group decision.
    • Authoritative: The individual is told whether or not to adopt it.


Figure: The adoption model on adopter characteristics best fitting Greenhalgh’s findings (three components):

3. Assimilation

Assimilation is the equivalent of adoption, but in more complex settings (while adoption is on an individual level). Assimilation is about adoption in an organization, team or department.  This process is usually vastly more complex than adoption on an individual level.

Assimilation shows a modest organizational parallel to the “stages” of individual adoption (knowledge-awareness, evaluation-choice, adoption-implementation). But it is clear that assimilation is a messy model on organizations moving back and forth between initiation, development, and implementation, variously punctuated by shocks, setbacks, and surprises.

4. Communication and Influence: Diffusion and Dissemination
  • Social networks: Adopting innovations is influenced by structure/quality of social networks
    • Horizontal networks (e.g. doctors amongst each other): key factor is peer influence
    • Vertical networks (e.g. doctors towards nurses): key factor is autoritative decision making
  • Homophily: Adopting innovations is more likely when people have similar socioeconomic, educational, professional, and cultural backgrounds as other adopters.
  • Peer opinion: Peer opinion leaders exert influence through their representativeness and credibility.
  • Marketing (Harnessing the opinion leader’s influence): Deliberately using opinion leaders to influence others. This generally produces positive but small results.
  • Expert opinion: Expert opinion leaders exert influence through their authority and status.
  • Champions: By supporting an innovation key individuals in social networks can facilitate uptake.
  • Boundary spanners: People with significant social ties in- and outside an organization willing to link the organization to the outside world in relation to this particular innovation, can facilitate adoption.
  • Change agents (Formal dissemination programs): 5 steps to increase effective dissemination of an innovation through a planned dissemination program (led by an external change agency):
    1. Consider all potential adopter’s needs and perspectives, particularly the balance of costs and benefits for them.
    2. Tailor strategies to the specific demographic/structural/cultural features of different subgroups.
    3. Use a message with appropriate style, imagery, metaphors, etc.
    4. Identify and use appropriate communication channels.
    5. Rigorous evaluation and monitoring of defined goals and milestones.


5. System antecedents for innovation

An organization will adopt innovations more readily if it:

  • Is large (size)
  • Is mature (maturity)
  • Is functionally differentiated; divided into semi-autonomous departments/units (differentiation)
  • Is specialized, with foci or professional knowledge
  • Has decentralized decision-making structures
  • Has slack resources to channel into new projects (resource slack is the opposite of resource scarcity)


Absorptive capacity for new knowledge:
An organization will be better able to assimilate innovations when it has:

  • Pre-existing knowledge/skills base: Capacity to link it with its own existing knowledge base
  • The ability to find, interpret, recodify and integrate new knowledge
  • Enablement of knowledge sharing via internal and external networks


Receptive context for change:
A receptive context towards adopting innovation contains:

  • Strong leadership and a clear strategic vision
  • Good managerial relations
  • Risk-taking climate: A climate conducive to experimentation and risk taking
  • Clear goals and priorities
  • High quality data capture


6. System Readiness for Innovation

Even though an organization might be amenable to innovation, it might not be able or willing to actually assimilate a specific type of innovation. This is referred to as system readiness for innovation. Factors influencing this system readiness are:

  • Tension for change: Innovation is more likely to be assimilated when staff perceive the current situation as intolerable.
  • Innovation-System Fit: An innovation fitting the organization’s existing values, norms, strategies, goals, skill mix, supporting technologies, and ways of working is more likely to be assimilated.
  • Assessment of implications: Innovation is more likely to be assimilated when its implications are fully assessed and anticipated.
  • Power balances (supporters vs opponents): Innovation is more likely to be assimilated if the supporters outnumber and are more strategically placed than the opponents.
  • Dedicated time/resources: When an organisation has a sufficient budget and adequate and continuing resources to allocate to an innovation, assimilation of that innovation is more likely.
  • Monitoring and feedback (capacity to evaluate the innovation): Having tight systems and appropriate skills to monitor and evaluate the impact of the innovation, increases the likelihood of assimilating and sustaining an innovation.


7. Outer Context (interorganizational networks and collaboration)

External influences on adopting an innovation within an organization are:

  • Socio-political climate
  • Incentives and mandates (political directives): Governmental funding streams for an innovation can facilitate adoption. External mandates (political “must-dos”) increase an organization’s predisposition (i.e. motivation), but not its capacity to adopt an innovation.
  • Inter-organizational norm-setting and networks (informal interorganizational networks): An important influence on an organization’s decision to adopt is whether a threshold proportion of comparable (homophilous) organizations have done so or plan to do so.
  • Environmental stability


8. Implementation process (implementation and routinization)

Implementation can be seen as “the early usage activities that often follow the adoption decision.” At the organizational level, the move from considering an innovation to successfully routinizing it is generally a nonlinear process characterized by multiple shocks, setbacks, and unanticipated events. The key components of (6) system readiness for an innovation are highly relevant to the early stages of implementation. Additionally, the following elements are associated with successful routinization:

  • Decision making devolved to frontline teams (organizational structure): Adaptive/flexible structures and processes that support devolved decision making (e.g. strategic decision making devolved to departments, operational decision making devolved to teams on the ground) facilitate implementation and routinization of an innovation.
  • Hands-on approach by leaders and managers (leadership and management): Top management supporting and advocating the implementation process, and continued commitment to it enhance routinization success.
  • Human resource issues:  Involving staff early and widespread through formal facilitation initiatives to enhance their motivation, capacity, and competence, increases success rates of routinization.
  • Dedicated resources (funding): Dedicated and continuous funding facilitates routinization/implementation.
  • Internal communication: Effective communication across structural (e.g., departmental) boundaries within the organization enhances the success of implementation/routinization.
  • External collaboration (interorganizational networks): More complex innovation implementation processes depend increasingly on interorganizational networks for success.
  • Reinvention/development (adaptation): Adapting an innovation to the local context, increases chances of successful implementation and routinization.
  • Feedback on progress: Accurate and timely info on the impact of the implementation process, increases the chance of successful routinization.


9. Linkage

Design stage:
For successful adoption of an innovation, there should be:

  • Shared meaning and mission: Developers and potential users share an understanding  of the meaning/value of the innovation.
  • Effective knowledge transfer: A shared language between developers and users for describing the innovation and its impact.
  • User involvement in specification: Developers should involve potential users during development.
  • Capture of user led-innovation: To capture and incorporate the users’ perspective.


Implementation stage (role of the change agency):
If a change agency is part of a dissemination program, adoption success depends on:

  • Nature and quality of linkage with intended adopters:
    • A common language, meanings and value system
    • Shared resources
    • Facilitation of networking and collaboration among organizations
    • Joint evaluation of the consequences of an innovation


External change agents:
Change agents employed by external agencies will be more effective if they are:

  • Selected for their homophily and credibility with the potential users.
  • Trained and supported to develop strong interpersonal relationships with potential users and to explore and empathize with user’s perspective.
  • Encouraged to communicate the users’ needs and perspective to the developers of the innovation.
  • Able to empower the users to make independent evaluative decisions about the innovation.



Greenhalgh, T., Robert, G., Macfarlane, F., Bate, P., & Kyriakidou, O. (2004). Diffusion of innovations in service organizations: systematic review and recommendations. The Milbank Quarterly, 82 (4), 581-629. doi:10.1111/j.0887-378X.2004.00325.x.