The diffusion of innovations model describes how change takes place within a social system and provides a schema for the systematic study of the adoption of a product, a practice, or an idea by members of a social system. The most commonly used definition of diffusion of innovations is that articulated by Everett Rogers (1995): ‘Diffusion is the process by which an innovation is communicated through certain channels over time among members of a social system’ (p. 5).

The model offers a logical fit with the traditional task of epidemiology—to systematically study changes in the health of populations with a focus on the patterns of disease occurrence and the factors that influence these patterns. The diffusion model offers opportunities to study and analyze changes in products ...