Kate Rushton , that is a great idea. The project would be focused on a community, but that community could be of any size or scale; if it is too costly to test the idea throughout an entire town, perhaps just testing it within a small neighborhood with diverse demographics would be a good option.
We could identify ~10 older citizens who are at risk of injury from falls and other preventable causes, 2 licensed doctors who are wiling to participate in the experiment for pay, and 2 nurses or similarly trained assistants. A team of 1 doctor with 1 assistant would visit each patient on a schedule, to supplement whatever healthcare they are already receiving and help to improve the health and safety of their surroundings at home.
After 2-4 months of implementing the program, we could compare results with those of a pre-program survey, and see how patients' well-being has improved as well as whether falls and other accidents have decreased.