Box 1: Origin and definition of frugal innovationFrugal means simple, plain, and using resources carefully. Frugal innovations are usually framed as innovations that are driven by resource scarcity and can refer to products, technologies, and services. 4 Frugal innovation can be traced back to the appropriate technology movement started in the 1970s by Ernst Schumacher. This movement focused on small scale, environmentally sound, people centred, and locally managed technology. 5 Despite varied definitions, frugal innovation is popular in many sectors, including healthcare. 6 Even though it is not always predicated on contributing to sustainability, it can lead to sustainable innovation. 7 Key criteria for a frugal innovation 6 1