The best way to learn what works well is to ask people who are already in the business of reaching at-risk populations. You can conduct a simple interview or survey with people in and outside your agency who routinely communicate with members of at-risk populations. This might include professionals such as first responders (fire, police, and emergency medical services), people who are in charge of programs such as Meals on Wheels, tribal elders, instructors in English-as-a-second-language classes, ethnic media representatives, and health care practitioners at clinics.
You will be able to use this information to start planning appropriate ways to augment your existing communication plan to include at-risk population outreach. This survey interview can help you identify practices that succeed—some of which you might want to incorporate in your plan—and those that failed to accomplish any measurable objective.