Is NPT restricted to complex interventions in health care?
No. We focus on health care because that is the area that most of work in. 'Complex Interventions' aren't restricted to health care though. Similar processes can be found in most kinds of organization - and the problem of 'embedding' new technologies and new ways of working is ubiquitous.

NPT doesn't seem to advance much on Diffusion of Innovations theory, how is it different? NPT is not intended to advance on Diffusion of Innovation Theory because it is about something different. Diffusion Theories are concerned with the transmission of innovations and often assume stages in transmission through social networks. NPT is concerned with what the work is as people seek to operationalise complex interventions and new technologies, rather than how innovations travel from place to place.

The mechanisms and constructs of NPT seem very rigid, are they? No, implementation processes, like other social processes, are dynamic and emergent. Their outcomes are often unpredictable and are always interesting. NPT gives us a way of understanding the drivers of these processes and a framework for exploring their effects.