Implementation of change in health care often has a focus on changing behaviour.  This can be challenging. Theories of change can help dissemination and implementation strategies by explaining how and why stakeholders might be influenced towards a desired outcome or describe the steps required for effective change.
We can organise theories of implementation in different ways. [1-3] One common way of thinking about different theories is whether they focus on the processes used or on what happened as a result of the implementation activity: 
Many of the generalised theories, models and frameworks (TMF) in implementation science draw on impact and process theories.  In this way these theories relating to change influence the activities associated with moving evidence to where it can be of benefit. Awareness of impact theories can be particularly useful in palliative care when you want to change behaviour of patients or health professionals.
Wensing  identified a number of impact theories relevant to change in health care. Information is provided below on some of these theories is described below where the impact is focused on individuals, on the individual in a social context, or the organisational system.
Process theories identify the elements that can influence effective implementation of change without articulating the assumption behind why the activity will drive change. Generally the theories of change are incorporated into a multi-step process to guide implementation at a practical level with an increased likelihood of success.  An example is the Knowledge to Action framework.
If you are interested in selecting a TMF to achieve behaviour change the supplement to Strifler's review of 159 TMFs is likely to be of interest. For each TMF the number of articles reporting on its use to assess level of behaviour change in individuals, organisations, community, or systems is indicated.  Application of TMFs to achieve individual-level change is common but less so for system-level change.
Read the NSW Agency for Clinical Innovation: Change management (110kb pdf)
Visit SA Health: Change Management toolkit
Read NHS UK's Leading large scale change: A practical guide (8.84MB pdf)
Last updated 06 May 2022